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Environmental control
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Utilities, conservation of resources and environmental control

Shade system to large glazed skylight

There is a general belief in the West that the oil-producing States of the Gulf are prosperous. This notion has been fostered to a large extent by the publicity given to the new life styles, the knowledge of the large oil and gas reserves, and the West’s general assistance in the development of the new States. It is also significant that the States set for themselves, or had set for them by the West, socio-economic development goals that were unrealistic and which, in endeavouring to attain them rapidly, created the impression of deliberately uncontrolled expenditure.

The four-fold increase in oil prices of the mid-seventies was met by considerable criticism and resistance in the West, though it was only thirty years since the Gulf States were able to share the profits from their own oil and gas. Regrettably, and for a number of reasons, within this period of time they were not able to develop the necessary diversified industrialisation and production bases, nor the indigenous labour development that would encourage self-sustaining growth.

The expansion, based on oil and gas reserves, has not been met with overall enthusiasm. A recent debate at the Qatar Foundation found a majority believing that ‘oil has been more of a curse than a blessing the Middle East’, though this was tempered by the realisation that oil in itself wasn’t the curse, but the way it was utilised.

During the explosion of wealth in the seventies, policies were formulated that were designed to improve the lot of both the Qataris and the expatriates who were brought in to assist with the administrative and technical functions required to develop the State quickly. A generous Government set no personal income taxes nor insisted on payment for water and electricity, among other things, despite advice from Western consultants of the necessity to establish the principle of payment for services provided by the State. With high personal incomes and expectations it was not unnatural that the consumption of these basic utilities would increase at an alarming rate to the position where summer requirements were only just matched by output.

In 1989 the Government began to tackle the problem in two ways: by an advertising campaign asking that electricity and water be sparingly used, and by the first demands to pay for utilities. This was begun only from expatriates who, although being the larger population, do not consume the greater amount of the utilities. Generally this was resented by many as none of the buildings occupied by expatriates – and nationals – were insulated and, consequently, required considerable power to keep cool in summer and warm in winter. The government’s policy was followed up in 1999 when it limited the provision of free electricity to nationals’ households with payment required for consumption above a set threshold.

This helped government when, in early 2000, it began the privatisation of its power generation and distribution systems. Under Emiri Decree 10, assets of the Ministry of Electricity and Water were transferred to the Qatar Electricity and Water Corporation – QEWC and known as ‘Kahramaa’ – the government retaining 43% of QEWC’s shares with 57% controlled by local investors.

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Conservation of resources

Much of the problem has been complicated by the manner in which designers have been trained and in which many of them practise. In addition to the normal programme requirements to which designers must respond, it is imperative that their constructed designs should respond well to the climate under which they been constructed. Although this element of the designers’ training is established as a normal educational requirement, it is surprising how soon it appears to be forgotten in practice, or how designers seem to be unable to make the changes required by working in a country whose climate and customs are so very different from those where they received their education. Reinforcing this problem, regrettably, is the fact that text books are soon out of date and that some books have information set out in them which is inappropriate or even factually incorrect. In today’s information climate, this is no longer a valid excuse for poor design.

Many of the expatriate consultants and designers seem to forget something of their training when they design for Qatar. To some extent they may be led into a state of suspended professionalism by a combination of the pressures on them to produce work to the timescales and value for money demanded of them, together with the apparent wealth of the society in which they find themselves. But although the State has considerable reserves of oil and, particularly, gas this is no reason why the standards of professional advice they would be required to give and apply in their own countries should slip.

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Islamic viewpoint

In particular they should be aware of the Islamic viewpoint where man is seen to be a guardian of the environment, safeguarding it for the future. The logic for this is that man contains the spirit of God – 38.72-73:

When thy Lord said unto the angels: lo! I am about to create a mortal out of mire, And when I have fashioned him and breathed into him of My Spirit, then fall down before him prostrate.

and has been given authority to act as God’s representative in relation to activities on Earth – 33.75:

We did indeed offer the trust to the heavens and the earth and the mountains; but they refused to undertake it, being afraid thereof. But man undertook it (the trust);

In accepting this trust, it is argued that man has accepted the responsibilities to act on behalf of God in an equitable manner. The exercise of this trust is codified by the sharia which establishes the manner in which man should interact with the environment. In this it is imperative for man to understand that, in acting on behalf of God, he is not setting himself up to compete.

More directly, man must understand that the Quran tells him that he has the authority, as well as the duty to safeguard the environment – 15.19:

And the earth – we have spread it out wide, and placed on it mountains firm, and caused life of every kind to grow on it in a balanced manner, and provided means of livelihood for you as well as for all living beings whose sustenance does not depend on you.

but, also that he is only a small part of the creation of nature – 40.57:

Greater indeed than the creation of man is the creation of the heavens and the earth.

The Quran enjoins man to use, but protect the environment. Many Muslim commentators now see that there is much in the Quran that points to man being appointed to the stewardship of nature. But both man and nature were conceived by God and so man must behave in a beneficent manner towards nature because, at the end of the day, he is going to have to answer for his actions – 36.54:

Then on that Day, Not a soul will be wronged in the least, And ye shall but be repaid the meeds of your past deeds.

There is much here that points to the sensible consideration of the use of resources in development, not just in the short but also in the long term.

Designers in the West are now familiar with the argument that the design and building of a project is likely to represent a very small percentage of the lifetime costs of that project – perhaps as little as 3-5% – and that the other costs will be expended not just in maintenance and replacement but in personnel, running costs and management. It follows that expenditure on a project which is designed to take account of the longer term costs in both financial and environmental terms, is money well spent.

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Carbon footprint

For that reason designers must make clients aware of this way of thinking. They should argue for the construction of projects with regard to ecological and environmental issues such as carbon footprints, and to build into their projects conservative systems for their running and management.

There are the beginnings of such initiatives in the region. A company in Dubai is considering a building which, they hope, will achieve a reduction in its total energy consumption by up to 65%, and water consumption by up to 40%. It will feature:

  • a 66 storey, commercial office tower,
  • 400 metres high,
  • with three 29 metre diameter, 225 KV wind turbines, and
  • 4,000 photovoltaic spandrel panels

to achieve the above-mentioned targets. There is likely to be some experimentation before it is completed and, they hope, it will set an example for future developments.

But a larger and, potentially more important, scheme has also been mooted in the United Arab Emirates, this time in Abu Dhabi. The importance of the project lies in its scale as well as its green initiatives. A six million square metre development is to be established with the intention of creating the first zero-carbon and zero-waste city in the world.

The city is interesting in a number of respects but it is particularly notable in that its design is based on traditional Arabic city design with a relatively high density and narrow, shaded pedestrian sikkak together with easy access to personal transport systems for those unable to walk easily or who need to travel to other parts of the regional network. The principle of using sikkak is in strong contrast to the character of buildings being produced in Dubai and Qatar and may signal a change in direction as lessons are learned from it.

I don’t intend to write about the issue of carbon footprints here as there is so much written about it elsewhere, though you should be aware that there is considerable controversy relating to its calculation and application. However, it is an issue that should be considered and raised in the design and construction of building projects, no matter how wealthy the client may seem to be. There is no reason why novel solutions should not be incorporated into buildings in the attempt to conserve resources: in fact, as I’ve briefly set out above, it’s a moral imperative.

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Electricity and Water production

Most of the country’s power plants are powered by natural gas due to the massive reserves under its control. By 2002, Qatar had an electric generation capacity of 1880 MW, producing 9.7 billion kilowatt-hours of electricity. This had increased by 2005 to:

  • Ras Abu Fontas A – 260 megawatts,
  • Ras Abu Fontas B – 609 megawatts, and
  • Ras Abu Aboud and sub-stations – 502 megawatts.

The residential sector consumes 70% of Qatar’s electricity, but this proportion is declining as the power demand associated with Liquid Natural Gas – LNG – export terminals increases.

Water production at the power and desalination stations are:

  • Ras Abu Fontas A – 70 million gallons per day,
  • Ras Abu Fontas B – 23 million gallons per day, and
  • Ras Abu Aboud – 8 million gallons per day.

Daily production at subterranean water wells is:

  • 5.1 million gallons.

The total design output capacity of water from all sources is:

  • 112.5 million gallons per day,

while the actual daily requirement for water is, in 2005, about:

  • 90 million gallons.

It seems obvious, and imperative, to inhibit the continuing expectation of relatively inexpensive utilities, and to encourage an understanding of – and a more conservative approach to – the use of limited resources. It is interesting that this is an issue bearing in mind how central the husbanding of resources is to Islam. At an international level the issues relating to a cleaner environment – pollution, the greenhouse effect and rising global temperatures – are beginning to be discussed within OAPEC, though in these initial stages it appears to be perceived as an issue relating more to the implications for their exports – oil and gas. Perhaps this shouldn’t be seen as a criticism as many Western and other countries either fail to believe in global warming or find themselves arguing about their position in the league of polluters, unable to bring their voting populations to make the necessary adjustments to their individual and collective life-styles.

Large quantities of water and electricity are consumed in Qatar for two reasons:

  • the harsh climate, and
  • the inappropriate response of building designers and users to the environment.

Construction of most buildings – which is discussed in more detail in the Gulf Architecture section – is virtually always with concrete frame and concrete block infill, rendered inside and out.

Water is used in massive quantities by everybody, and the only effective cooling systems are those supplied by air-conditioners – mostly wall mounted with some split systems and a relatively small percentage of central systems. It is notable that many of the Gulf countries are continuing to reinforce the use of air-conditioners by developing their own industries as a part of the general principle of industrial expansion.

There seem to be two general issues that must be approached in resolving the problems associated with utilities:

  • firstly, the production of the utility and,
  • secondly, their use.

As noted above, the production of electricity and water takes place in two sea-side sites, Ras Abu Aboud and Ras Abu Fontas, which are three or four kilometres apart just outside Doha. The electricity is supplied to the national grid which is supplemented by diesel generation in some of the more outlying areas. Water is mixed with well or ‘sweet’ water to make it more palatable, and distributed through an underground system of mains supplemented by tanker delivery where necessary.

Ras Abu Fontas was planned to accommodate six gas turbines and six desalination plant units, but this was increased to fourteen of each due to hesitation in proceeding with a planned power station north of Doha at Al Lusail.

In order to improve the supply of electricity, Ras Laffan Power Company Limited – RLPC – was established by Emiri Decree 44 in 2001 to operate Ras Laffan power and water station. It was promoted as a strategic step to confirm Qatar’s commitment to implement and expand the privatisation programme of the country’s electricity and water sector. The company is owned by Qatar Petroleum – 10%, Qatar General Electricity and Water Corporation – 25%, Gulf Investment Corporation – 10%, and AES Ras Laffan Holdings – 55%. The aim of the project is to establish and operate a gas-driven power generation and water desalination station with an output capacity of 750 MW of electricity and 40 million gallons of water.

However, there is still concern for consumption. In August 2005, Qatar announced a five-year plan to double the nation’s electricity capacity, which includes the building of major primary substations and secondary substations. The demand for electricity in Qatar rose 16% in 2004, with power outages experienced in parts of Doha due to overloads of the power distribution grid. This was a relatively common occurrence in the nineteen seventies and eighties. Qatar’s booming economic growth, accompanied by large-scale infrastructure projects, has applied considerable pressure to the nation’s electricity supplies.

Hostilities in the Gulf war demonstrated the vulnerability of the power stations to the threat from oil in the sea, and it was only by a concerted effort involving successive barriers and labourers in the water removing lumps of oil that the intakes to the power station were kept clear. Tankers cleaning their tanks illegally continue to represent a problem, and it will require only a single serious oil spill to require the power stations to shut down. Hulls of ships sunk in the Gulf war discharged oil for some time and, as yet, there is no legislation for dealing with the dumping of industrial or chemical waste into the sea. The Environmental Protection Committee is in its infancy and is may not be able to deal effectively with an emergency. I do not know what supply of water there is in the reservoirs, but it has been as low as two days. Although the situation is not precarious it is obviously not ideal, and complacency has to be avoided.

Alternative sources of utility production have been looked at by the State over a period of time, but none looks as promising as those associated with the use of their greatest resource – gas from the North Field – which is situated under the sea north-east of Qatar, and which has a conservative capacity of over a hundred years’ supply.

As for other sources of power, political consideration will not allow the State to build nuclear plants, the sea does not have the range of tides necessary for wave action to power suitable generation systems, and the wind is neither constant nor strong enough for this purpose. Photovoltaic and other systems are still too early in their development stages to have an impact upon thinking in Qatar.

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Quality of electricity and water


Electricity

The State provides an electricity supply to the consumer through 132kv, 66kv and 11kv sub-stations, feeding 416v to major projects and 240v to domestic consumers. In the past there has been criticism of the supply on two accounts:

  • firstly, the possibility of a break in supply caused by over-consumption – or under-provision, depending on which way you look at it – and,
  • secondly, the lack of stability of voltage.

The first issue is a direct function of the inability of the Ministry to produce the quantities demanded by consumers. This is now being dealt with by the methods discussed previously. Until the advent of automatic switching it was possible for greater continuity in the electricity supply to be organised from the sub-stations, but this has now suffered from automation which has not been as responsive as the previous manual system.

Some concern has also been felt for what was thought to be extremes of fluctuation of the electrical supplies, and there have been claims that domestic supplies have varied between 220v and 260v. Although there have definitely been variations in the current supply it is probable that these figures are exaggerated, as is claimed by the Ministry. However, equipment has been damaged by some eccentricities of the system, though it might be due to any combination of poor electrical installations, irregular voltages, unsuitable equipment, high humidity and temperatures.

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Water

Water has also been a problem in many respects; those relating to supply are dealt with elsewhere.

The quality of the water in Qatar is an emotive subject, especially to those who have had a traditional relationship with the desert. Many Qataris who have spent time in the desert, and even those who have lived in the towns, have come to recognise the flavour or tastes of the various wells. In the nineteen seventies, with the increase in size of the towns and the associated problems of pollution of the water supplies both by saline ingression and septic tanks, Qataris became increasingly sensitive to good sources of water. Itinerant water sellers were a common feature on the roads of Doha selling water from oil drums on carts pulled by donkeys. In the desert the drilling of wells was an important factor in the development of cultivated gardens based on the areas of rawdha or sweet soil. It was, and still is common to see Qataris sampling the water from the ground in different parts of these gardens in order to identify the best tasting water for domestic consumption. In fact there are three Qatari companies abstracting water and selling it as mineral water as there is a universal dislike of tap water. These companies compete both with companies within the Gulf, but also, to a lesser extent, with the more well-known Western brands.

There are four reasons for this concern for water.

Firstly, a mains supply to all houses has not been fully implemented – some of the newer residential areas still having a tankered supply. The mains are not always well constructed and there has been a serious problem with the ingress of polluted water into the mains. This, and other problems, have been exacerbated by the rising water table below Doha and, to a lesser extent, other Qatar towns.

Secondly, the general arrangement of water supplies to residential properties leads water into a water tank at ground level from where it is pumped to a roof tank. Generally there is insufficient pressure within the Ministry’s distribution system to enable the roof tanks to be filled without a domestic pump boosting it up to the roof.

The third problem relates to the materials through which the water is led. For some time, with the increasingly common introduction of copper piping within houses, pipework distributing water was mostly of galvanised steel ostensibly to British Specifications – a requirement that was rarely maintained by contractors.

Finally, the water that was given to consumers was a mixture of desalinated water from the power stations and well water together with some chemicals designed to rectify the more glaring omissions from these two sources. This water is acidic and attacks many of the materials with which it comes into contact.

All these factors have conspired to affect the safety and taste of water supplies. Water supplied to the domestic tap in many parts of the country can be a reddish brown in colour and flat or insipid to taste. Those who experience this problem first pass it through a filter, and it is common to boil it or use it only when taste is not a factor. Because of this, bottled mineral water is consumed in large quantities in Qatar, and there are still some who prefer to have water tankered to their house when the alternative supply from steel pipes is heavily coloured.

Towards the end of the nineties the Ministry of Electricity and Water embarked upon a programme designed to rectify many of the problems associated with the quality of water. With the introduction of two chemical treatment plants potable water was re-carbonated and fluoridated.

Re-carbonation is designed to re-introduce into the distilled water calcium bicarbonate which it has lost in the distillation process and, at the same time, convert the aggressive character of the water to a more neutral, non-corrosive one. It is recognised that the ensuing harder water causes problems with furring of heaters and kettles as well as lathering of soap, but it is thought that, on balance, it is a sensible upgrading to the potable water supply.

Fluoridation has been discussed in Qatar and elsewhere for years, and proponents and opponents of compulsory fluoridation have not yet come to a meeting of minds. The Ministry elected to add the chemical to the distilled water for the general benefit of the population. It is interesting to note that most of the wells have a very high fluoride level – higher than 3.5 parts per million – and a level which is associated with endemic cumulative fluorosis, contributes to skeletal damage and was common in Qatar prior to the public supply of potable water. The level of fluoride in the programme will be held to between 0.6ppm and 1.0ppm in conformity with the World Health Organisation recommendations for the Qatar climate.

A warning about water consumption

The issues arising from the use of water are increasing around the world, not just in the Gulf but, as can be seen from this newspaper article in a local newspaper, August 2008, there is concern in other parts of the Gulf as well as Qatar. The increasing use of water is due to a number of factors which are socio-economic and even cultural in character, and may not be easily diminished as there is still the belief that there are funds enough to guarantee continuing consumption.

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Solar power

For some people, an interesting potential source of power common to the region is that of solar energy. Experimental work is being carried out on this within the region where Saudi Arabia, Abu Dhabi and Kuwait are carrying out experiments as well as constructing projects such as the initiative at Masdar, to test their work. Previously desalination plant producing about 80 tons a day and powered by solar energy was constructed in Abu Dhabi in 1984.

Of course elsewhere in the world similar work is being carried out. The general consensus appears to be that crude oil will continue to be the main source of energy for the world, its contribution to the energy consumed remaining in the range 40-45% of the total demand for some time. Although solar energy is anticipated to grow at around 15% p.a., its contribution to the total energy requirement of the world will not exceed 0.5% for this time. Qatar is considering research into the field but little of practical effect has been carried out so far.

A number of proposals involving foreign Universities and Qatar have been discussed but mostly seem to be speculative. It was foreseen that there would first have to be a foundation for the teaching of research work to students, and that this might be followed by research in Qatar on the specific problems the State faces such as those relating to cooling water in greenhouses. At a later stage it was thought that there might be a demonstration of the practical applications of the work through the construction of prototypes. There have been discussions but it seems that the objective moves with time. It appears to be realised that solar energy provision in Qatar is unlikely, but that there might well be development aimed at helping less fortunate countries.

The Qatar State Electricity Department has experimented with the use of a number of small commercial packages to light isolated mosques and gardens in the desert and have experienced a number of problems, particularly in the electronic circuitry associated with the solar cells as well as the omnipresent dust. It is felt that the state of the art is not yet sufficiently advanced to take account of the extremely high ambient temperatures in Qatar. If it is decided to move away from the present methods of energy supply, a solution is more likely to be found in solar reflectors concentrating heat to produce steam on a large scale, rather than on the domestic scale implied by commercial solar panels.

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Well water

If this were to happen the well fields would not be able to cope. Qatar lies over a large body of water in the centre of its land mass, but this supply has been steadily compromised by three factors: the over-consumption of well water both for drinking and farm irrigation, the failure of the rainfalls to replenish the field, and the progressive concentration of salts in the water due to saline water incursion, increasing fluoridisation and the depositing of nitrates from the agricultural farms.

In the past Qatar was well served by the body of sweet water below its surface, and this was one of the reasons for its popularity with the Bedu who moved into Qatar in the winter months from the Arabian hinterland. Even today the quality of this water is appreciated by many Qataris and two suppliers of bottled water obtain their supplies from this reservoir. Although there have been attempts by the Government to regulate the abstraction of water from the well fields this has not been successful, nor have there been the amounts of desalinated water to recharge the reservoir, although this has been mooted from time to time. It had been intended that Al Lusail would systematically recharge the underground reservoir with its surplus but, without the water that would have been injected if it had gone ahead, there is now a significant problem underground. With present policies it is anticipated that the well fields will last, but with increasing associated difficulties.

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Comfort

The enjoyment of comfort in buildings is essentially a function of three factors:

  • relative humidity,
  • temperature, and
  • the rate of air flow across the body,

to which can be added a factor relating to the amount of activity carried out by the individual. This latter factor needs to be considered both for the activity carried out

  • within a particular space, as well as for
  • a change in the level of activity either
    • within the space or, more commonly,
    • for a person entering or leaving the space.

For instance it is common for a person coming into a space from the outside – even if it’s just the car – to want an immediate cooling effect. It is not uncommon for people having central cooling systems to have an additional, local, cooling system that will give an immediate burst of cold air to cool them down.

Kitchens are normally the most difficult rooms to deal with but spaces such as majalis can require additional cooling due to the numbers of people using them and their doors being left open. The kitchen is really a separate problem and I’ll deal with that later in addition to the requirement for conditioning areas where waste is stored.

Physical, psychological and psychosomatic difficulties can be caused or aggravated by artificial environments, and this has been exacerbated by the speed with which this change has been accepted into the society. Inevitably there is a learning curve in the acceptance of air-conditioning systems both in the hot, summer months as well as the colder, winter months.

The initial use of air-conditioning in the Gulf was in the provision of wall-mounted, separate units. Electricity was provided in three phases and, with the regular cutting of one or more of the phases, it was common for householders to have a long cable which, in the event of a partial cut, could be taken to whichever socket outlet was still working in order to provide power to the room where cooling was needed. These units were then developed to incorporate a heating coil for the winter, providing year-round conditioning to the main rooms of the house. Only storage and bathrooms were not provided with conditioning.

Wall-mounted units are extremely noisy, not just in themselves, but also in the reverberation and vibration they create. People got used to this noise and, with the advent of central systems, there was the anticipation that there should be noise associated with them as well. In fact the lack of noise was sometimes criticised. However, since those days my experience is that it is noticeable that Gulf installations can be much quieter than those now being installed in Western countries.

High temperatures may not be uncomfortable if there is little humidity or if there is a relatively high flow of air across the body; comfort may also be enjoyed with high humidity at low temperatures or modified by relatively high air flows. As body’s temperature approaches the temperature of the surrounding air the normal methods by which it loses heat – by evaporation and radiation – become less effective. Increasing air motion across the body becomes more important as a means of achieving some degree of comfort. At its simplest, the use of a manually operated fan traditionally cools in hot climates.

Human body temperature is normally about 37°c, and must maintain a relatively constant state within a wide range of environmental conditions if illness or injury is to be avoided. It is subject to the same laws of physics as are other objects in that it gains or loses heat by

  • radiation through space,
  • conductance between bodies and/or substances with which it is in contact,
  • convection involving the transfer of heat from a warm body to a body of air above it, and
  • evaporation, which requires the body to give up some of its heat.

Unlike many objects, however, the body generates its own heat through the intake of food, and the heat generated by the metabolic processes must be dissipated. At rest the average adult male generates approximately 290 BThU/hour and, although the rate can be increased eight times by violent exercise, over a twenty-four hour period, heat production is likely to be 130% for sedentary work and 300% for heavy manual labour.

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Heat gain and loss processes for the human body


Mechanism

Gain process

Loss process

 

 

 

Metabolism Basal heat production
Digestion
Activity
Muscle tensing and shivering in response to cold
 
Radiation From solar radiation – directed and reflected
From radiation by radiators
To the surrounding air
Conduction From air above the skin temperature (increased by air movement)
From warm bodies in contact
To air below skin temperature

To cooler bodies in contact
Evaporation   From the respiratory tract
From skin covered with perspiration or applied water

 

In the past traditional architectures developed to provide a degree of natural conditioning in order that the users of buildings could live a more comfortable life. Over the last three thousand years in the Middle East these systems became quite sophisticated and have worked surprisingly well. Now, with a number of people calling for a return to traditional systems there is an increasing interest in seeing their return to ‘solve’ the problems of modern architecture in relation to what is seen to be their over-dependence on expensive supplies of electricity and water.

However, three points have to be borne in mind when looking at the way buildings are designed to respond to their climatic environment.

  • Buildings used to have openings in them which are nowadays closed by glass. Window openings were
    • situated at a relatively low level,
    • barred for security – particularly if within a room on an external wall as, typically, was the majlis, and
    • had wooden shutters for additional security as well as privacy.
  • In the past, families using their houses did not have the range of personal and family possessions that are now common in all houses. Traditionally many of these possessions would be moved physically from room to room as the hourly conditions and social habits had occupants move in the past. Nowadays most furniture in a Qatari house is neither designed nor constructed to be able to accommodate the temperatures, humidity and dust of the Middle East – even that furniture which is built and sold within the region.
  • Related to the second point is that fact that the activities carried out in modern houses are different in range and degree from the past. It is a fact that some air-conditioning is required in all modern houses in the Middle East, and that the best that can probably be aimed for is a minimal use of modern conditioning methods where users will allow and require it. For without their demanding it there will never be a reason for requiring the more traditional, passive air-conditioning systems. Particularly, with those who are living in modern houses for the first time, there appears to be an overwhelming desire to ensure they enjoy the immediate response of cold air and flowing water.

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Heating delay

The construction of buildings in Qatar was generally from relatively massive walls of stone – hasa – and limestone mortar – juss. These walls had a considerable potential thermal mass in them and, additionally, took some time to react to the solar radiation which was the main heating element upon them. The architecture that developed had three essential characteristics from the point of view of environmental performance:

  • heavy load-bearing walls,
  • tall internal volumes, and
  • relatively small openings.

The external walls absorbed the heat from the sun slowly, building up their heat throughout the day with the internal face of the rooms developing their heat only slowly with the passage of time. Within the rooms the relatively cool night air was trapped for the enjoyment of the users through the day and, by the late afternoon when the walls were at their warmest, their effect would become noticeable inside the rooms. At that time the windows would be opened both to facilitate better air movement and to allow the ingress of the cooler evening air. This would begin to cool both the inhabitants and those elements of the interior of the building which had become warm through the day, whilst the building would begin to lose its heat through convection and re-radiation.

One specific characteristic of the warming of the massed walls was the need to keep away from them by the late afternoon. The heat gain in the walls radiates as low wave energy and, sitting close to them can cause discomfort and, in some cases, illness in those not aware of the effect.

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Shading

Traditional Arab towns, particularly those in the Gulf, were well designed for protection from the sun. Their irregular plan form with its narrow thoroughfares and close compaction exposed only the minimal areas of building mass to the direct rays of the sun. The introverted courtyard always gave, somewhere inside it, shadows to the benefit of the user and, with careful design, was able to optimise the requirement for coolness in the summer as well as assist in keeping the occupants warm in winter, a requirement which is often overlooked. In many parts of the Middle East housing developed a number of rooms with specific characteristics usually responding to times of the year. In some northern Arabic houses there developed summer rooms and winter rooms, the former north facing and the latter south facing – both of which were used in conjunction with the east- and west-facing rooms to give a usable house, winter and summer.

In Qatar there was apparently little need within the relatively small housing complexes for this refinement. Beside the sea, where the majority of the towns developed, houses were normally orientated with regard to the sea in order to take advantage of the prevailing on-shore/off-shore breezes. In practice houses at ground floor level were sited to turn their backs to the north and west, and on the first floor, to the west or to the north and west. Inland houses were all sited to turn their backs to the north and west and, in this, partly reflected the practice of locating traditional tents with their backs against the shamal from the north-north west, adding to this the need to protect the residents from the strong, setting summer sun. This also had the advantage of reducing solar loading on the structure – tent or load-bearing wall.

Within the courtyard the houses normally had a verandah facing the south which gave protection from the direct rays of the sun in summer but permitted a sun of lower trajectory in winter to have some beneficial effect on the rooms behind the verandah. The second storey development in Qatar was nearly always on the west side of the complex and this aided in providing shadow to the users of the house. Finally, within the courtyard, there would nearly always be a tree to give additional shading from the intensive summer climate, and both aural and visual relief.

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Environmental damage

We have all benefited in recent years from the invention and introduction of chemicals that were intended to make our life better in a variety of ways. We have now discovered that this progress has been made at considerable cost to the environment and that we are now at risk from the repercussions of the very inventions designed to improve our lives.

Over a period of years there has been considerable publicity given to an assertion that the ozone layer protecting the earth is being damaged by emissions from a variety of sources. The increase in concentrations of greenhouse gases – carbon dioxide, methane, CFCs and nitrous oxide – were specifically singled out for concern. It was held that, unless methods are found to stop and reverse the present trends the earth will be damaged from the warming that will affect weather patterns, temperatures and sea levels, as well as from a variety of other factors. Now, scientists state that not only is the damage to the ozone layer halted, it is healing. It is not possible to determine at the time of writing if this is a definite reversal of the damage or a temporary halt to be followed by a continuation of the damage. Whichever it is it seems sensible to continue to assume that chemicals and practices that damage it should be stopped.

The chlorofluoro-carbons, CFC-11 and CFC-12, are recognised as being two of the more dangerous of these compounds, their prevalence being due to the low cost of their basic chemical – carbon tetrachloride. Breaches of the ozone layer are linked with increase in skin carcinomas, cataracts of the eyes and global warming – the latter leading to unpredictable climatic changes and rising sea water levels. As well as being used in the construction industry where they are used to blow foamed insulation products, CFCs are also used extensively in air-conditioning refrigeration systems and in fire protection equipment.

It is anticipated that CFCs will eventually be replaced by hydrofluoroalkenes (HFAs) – a group that includes hydrofluoro-carbons (HFCs) and hydrochlorofluorocarbons (HCFCs) and which have a much lower ozone depleting potential (ODP) as well as a lower global warming potential (GWP). In particular, HFC-141b is likely to replace the discredited CFC-11 as HFCs tend to have ODPs in the region of 0.05 compared with CFCs of 1.0. However, this is still recognised as only a medium term answer to the problems facing the ozone layer.

At present this is seen to be a medium term answer to the serious problems created by substances escaping into the atmosphere. It is realised that, even if the production of CFCs could be halted immediately, it would take until the 2070s for the chemical compounds already in the atmosphere to break down. Pressure is mounting to place an immediate ban on compounds that release chlorine – the element causing destruction in the ozone layer – into the stratosphere, but there are three arguments militating against this policy:

  • the Third World generally will contribute an increasing proportion of the damage to the environment in their determination to improve their industrial bases and, perhaps, their lack of concern for the dangers perceived by the richer industrial Western nations,
  • secondly, there are rearguard actions being fought within the West against stopping the use of chemicals such as CFCs as well as the more dangerous methyl chloroform which is found in uses ranging from electronics to typewriter correction fluid, and
  • thirdly, some scientists believe that the openings in the ozone layer have stopped and may or will be reversible. It is seems safer to assume the danger still exists and to continue to attempt to prevent it.

In addition to the hole in the ozone layer over the Antarctic there is concern for the Arctic, an opening there caused by bromine which is used in halons such as those employed in fire extinguishers. Levels of methyl bromide are increasing at up to 15% per annum. Unless there is:

  • universal recognition of the dangers posed by the use of dangerous chemicals,
  • a considerable improvement in the pace of invention of ecologically safe technologies,
  • a concomitant transfer of these technologies from the West to the Third World,
  • the re-introduction of environmentally safer design, and
  • a real attempt to use these technologies world-wide

there will be grave and increasing dangers for the World.

A number of institutions are attempting to come to terms with reducing the use of CFCs and are issuing guidelines on the appropriate use of materials. The Environmental and Energy Policy Committee of the Royal Institute of British Architects, for example, has suggested that the following guidelines should be followed by members:

  • Avoid the use of CFC blown materials. This would include polyurethane, polyisocyanurate and phenolic foams, extruded polystyrene and aerosol sprayed foam insulation.
  • Use built forms and fenestration that permit natural or simple mechanical ventilation, eschewing full air-conditioning and the use of associated refrigeration plant.
  • Where refrigeration plant is necessary, ensure that there is compliance with the CIBSE policy on CFCs – use refrigerant R22 until safer substitutes become available; ensure adequate design permits suitable maintenance to provide long term containment; include access space for leak checking as leakage currently accounts for 50-75 per cent of refrigerants used; incorporate detection alarms; require refrigerants in refurbished or decommissioned plants to be re-cycled.
  • Avoid the use of halon fire control systems particularly as fire tests usually require full-scale release of the gas. Investigate ways of minimising leakage.

The policy statement from the Committee also sets out a series of steps it recommends its members take:

  • At the outset refer to BS 8207 and the Energy Efficiency Office ‘Best Practice’ documents.
  • Specify low-energy, high efficiency plant, fittings and appliances.
  • Employ up-to-date controls to ensure that buildings respond appropriately to internal and external conditions.
  • Ensure that buildings are orientated and respond to natural features and micro-climates.
  • Specify timbers only from sustainable forests.
  • Ensure that insulation standards are at least up to present requirements and that buildings are air-tight within ventilation recommendations.

The recommendations go on to suggest a number of initiatives by Government:

  • Provide substantial subsides for retro-fit insulation, perhaps linked to national energy design advisory scheme.
  • Introduce minimum efficiency standards and labelling for plant and appliances.
  • Require privatised utilities to promote energy conservation.
  • Make initial subsidies for manufacturers of low-energy fittings until production achieves economies of scale.
  • Introduce mandatory energy efficiency rating of all new domestic buildings.

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Sick building syndrome

There is considerable concern in the West for the problems suffered by occupants of deep buildings which have an artificial environment. The syndrome demonstrates itself with occupants suffering from a range of maladies from headaches, running noses and eye strain to a number of psychosomatic complaints which might not, on first examination, appear to be related to the building in which they are working. Common consequences are a general disaffection with work and an increase in absenteeism.

The problem appears to have two basic causative components:

  • there are physiological aspects caused by the treatment of the air within buildings and the amounts of chemicals and dust moved around it by the air-handling system, but
  • there are also respectable arguments which suggest that unnatural surroundings and the feeling of a lack of control over the occupants’ surroundings give rise to strong psychological tendencies leading to loss of output and absenteeism.

The factors which seem to be common to buildings where there is considered to be the presence of sick building syndrome have been further characterised as having:

  • hermetically sealed air-tight shells,
  • mechanical heating, ventilating and air-conditioning systems,
  • materials and equipment giving off irritating and toxic fumes and/or dust,
  • fluorescent light contributing to photochemical smog,
  • the application of energy conservation measures, and
  • a lack of individual controls.

To some extent these difficulties have to be considered in domestic buildings within the Gulf because, in the nature of their design – particularly the manner in which they are serviced, their component materials and their links with the outside – they can demonstrate many of the characteristics of larger commercial developments.

The problems which are now seen to be associated with the servicing of buildings have recently combined with the ‘green’ concern for the environment and the conservation of resources to create a setting for more novel approaches to the design of buildings as a whole. What is significant about these approaches is that they demonstrate that the problems will not be resolved purely by eliminating the creation of chlorofluorocarbons and the use of endangered hardwoods. Given that the United States is unwilling to make a significant impact upon the reduction of contaminants in the environment either within its own borders or, by extension, upon other countries of the world; and that Third World countries see themselves necessarily using irreplaceable resources or pollutants in their drive towards their own development, then it is inevitable that countries generally will attempt to live with reduced levels of pollution rather than try to eliminate them to the benefit of the world. However, in the West it is inevitable that designers should attempt to improve their buildings within the framework of the palette of materials and practices that are being developed in response to environmental concern.

A report on the subject makes some interesting points about the costs of building in environmental terms. For instance, although they claim that concrete frames are ‘greener’ than comparable steel frames in terms of energy use, the report goes on to say that laminated timber from renewable sources would be even better for the environment. For some time now there has been concern for materials which are commonly utilised within buildings, but these concerns – like those relating to the over-consumption of electricity and water within Qatar – have not really percolated through to the users of buildings within the State, nor in any large degree to those who create and control the development of buildings for them. Consequently there are a large number of areas for improvement in the performance of buildings, although there is the real possibility that, certainly in the short term, the costs of construction will rise.

The common building materials in Qatar are concrete and concrete blocks, but these materials bring with them a range of problems, particularly in their poor response to the aggressive climate of the region. However, it’s not just the climate that creates difficulties for the designer; there are a range of problems for the designer to consider and for the user to be concerned about in the character of the limestone from which the aggregate is obtained and the qualities of the cements.

The limestone of the country is relatively soft and initiatives to introduce aggregates from outside have been unsuccessful with the exception of those for the marine defences of the Corniche. The limestones yield aggregates that are porous, absorptive, relatively soft and excessively dusty on degradation. Dust and excess fines result in lower strength concrete and significant shrinkage.

These problems are exacerbated by the aggregates’ developing chemical reactions within the concrete. A number of reactions occur within the concrete:

  • reactive chert and flint which occur as nodules in local limestones generate silica-cement reactions,
  • carbonate-cement reactions develop more slowly with the presence of carbonate-rich clay in the crystalline structures of dolomitic limestones causing volume disruptions,
  • there is extensive contamination of salt in the limestone aggregate, affecting expansive sulphate reactions and electro-chemical corrosion with reinforcing steel, and
  • there is significant cracking and spalling due to the progressive growth of salt crystals.

Concrete can demonstrate deterioration within fifteen years of construction and a number of buildings in the Gulf region have had to have remedial works carried out on them. Commonly, and in decreasing order of importance, concrete suffers from

  • reinforcement corrosion,
  • sulphate attack,
  • salt weathering and cracking due to shrinkage,
  • thermal gradients, and
  • aggregate-cement reactivity.

In order to obtain a sound construction there are no short-cuts. Nor is the method for obtaining a good product any different from what is required any where in the world: a well-considered specification along with sound construction practice. It is suggested that the criteria for specifications should be based on considerations of strength and durability, though it is notable that in certain cases these can be contradictory. Aggregate evaluation and gradation, binary aggregate proportions, cement type and content, water-cement ratio with respect to strength and permeability considerations, type of reinforcement and depth of cover are the issues that have to be concentrated upon in order to deal with this issue satisfactorily.

It is not just the selection of the materials of construction which are sometimes suspect; there are also potentially dangerous materials which are not always considered by designers and builders. Products such as

  • those incorporating asbestos are no longer imported to Qatar from Europe, although it is still possible to find them in other countries of the world;
  • materials utilising fire retardant chemicals have an affect upon the users of buildings either through allergic reactions or, in the event of fire, through inhalation poisoning;
  • concerns are also expressed for the carcinogenic effects of certain wood preservatives, particularly those incorporating chemicals such as the fungicides tributyl tin oxide (TBTP) and pentachlorophenol (PCP) or the insecticide Lindane;
  • rigid urethane foams are now recognised as being dangerous and aerosol devices attack the ozone layer;
  • although it is preferable to have timbers treated at the factory with low toxicity preservatives such as copper or zinc naphthenate, there is always the possibility that treatment will be site supplied, sometimes within an air-conditioned environment for finishing works; and
  • working within a conditioned environment also tends to increase the concentration of fumes from a variety of paints, varnishes solvents and other chemicals, and there are serious risks to workers or residents from this work.

There are few statistics relating to the presence of toxins within buildings except the radioactive gas radon and, because of this, Bristol University carried out research into the presence in homes of nitrogen dioxide, volatile organics, formaldehyde, ammonia, viable particulates such as mould, mites and bacteria, air leakage rates, temperatures and humidities. A three year study was carried out into the manner in which housing improvements relate to health. In general there is the feeling that improvements in heating and ventilating have generally improved air quality, but that changes in the manner in which buildings are constructed have introduced volatile elements from which occupants and site operatives are at risk in varying degrees.

An interesting and possible solution to many of the chemical causes of sick building syndrome within buildings has been suggested by scientists at the National Aeronautical Space Administration working on alternative ways to purify air in space craft. They have found that plants have been found to eliminate up to 87% of air pollutants within a twenty-four hour period and that, for instance, fifteen Mother-in-Law’s tongue plant will keep 160 sq.m. of office or house formaldehyde-free. They have discovered that certain plants can be effective in dealing with specific chemicals:

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Pollutants, sources and solutions


Pollutant

Sources

Solutions

 
formaldehyde foam insulation, plywood, clothes, carpeting, furniture, paper goods, household cleaners philodendron, spider plant, golden pothos, bamboo palm, corn plant, chrysanthemum, mother-in-law’s tongue
benzene tobacco smoke, petrol, synthetic fibres, plastics, inks, oils, detergents, rubber English ivy, marginata, Janet Craig, chrysanthemum, gerbera daisy, warneckei, peace lily
trichloroethylene dry cleaning, inks, paints, varnishes, lacquers, adhesives gerbera daisy, chrysanthemum, peace lily, warneckei, marginata

In addition to the benefits to be gained from plants, the simple cleaning of buildings is also likely to have a significant effect upon reducing sick building syndrome. The steam cleaning of three offices reduced mites and, with them, a forty per cent reduction in the symptoms of the syndrome. Research in Finland has also discovered that raising humidity by twenty per cent and keeping the temperature below 21°c also reduces the symptoms of eye, nose and skin irritation, headaches and lethargy.

Contrasting with this is the claim that lowering humidity will give long term relief to sufferers from asthma, hay fever and other allergies. House mites have been identified as the main cause of asthma. Buildings which have limited ventilation tend to increase the growth of house mites. The study claims that the threshold limit value for maximum exposure below which there is no increased disease risk, is 100 mites per gram of dust. This requires a maximum indoor humidity in winter of 7 gms/kg. This can only be achieved by mechanical ventilation with heat recovery, where at least one air change per hour is necessary. The Building Research Establishment tends to confirm this in their experiments carried out in February 1992. Mechanical ventilation with heat recovery provided homes with no more than 100 mites per gram of dust. The control homes demonstrated ten times that number of mites.

It is recommended that the problem must be tackled at source as traditional methods of ventilation have little or no effect on the problem. Opening windows produces high energy loss and there is a large reservoir of water vapour within buildings in their building materials, fabrics, furnishings and natural human respiratory functions. It is suggested that designers should:

  • avoid building materials that produce organic pollutants such as particle board and foam insulation,
  • reduce pollution before the building is occupied by ventilating before decorating,
  • avoid damp proof materials that release toxic chemicals,
  • apply wood preservatives at the factory and not on site,
  • avoid the use of lead based paint primers,
  • surround fibrous loft insulation materials with a membrane,
  • ensure a good membrane or proper sump where the area is prone to radon, and
  • use low energy artificial lighting with high frequency ballast to eliminate the flicker which causes eye strain.

In addition to the problems of poisoning of occupants and site staff there are the problems associated with the treatment of the site in the construction stages. Small scale domestic projects are rarely well organised. Site staff will have had little experience and no training in the hazards associated with pollution of the site and its surrounds – either to themselves or to the general environment. In addition to the normal fly tipping which is difficult to control, it is not uncommon in Qatar to see dumped concrete, cement slurry which can find its way into the underground water systems, plastics and other building materials buried in the site, and the spilling of diesel oil from the generators.

Finally, there are the problems associated with sites which are not readily perceived, and for which no work has been carried out in Qatar. Radon, for instance, has caused significant problems elsewhere in the world and, where it is formed below sites it must be abstracted safely and disposed of. Hazardous wastes do not appear to be a problem at this stage in the development of Qatar, yet there are no comprehensive methods for dealing with the safe disposal of waste and the safeguarding of sites in the long term. Regrettably, in most parts of the world codes have only been discussed when there is perceived to be a problem.

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Legionnaire’s disease

As yet there have been no reported incidents of Legionnaire’s disease in Qatar although a limited survey of hot and cold water systems in different British buildings demonstrated that a high proportion of them contained legionella bacilli. Legionella occurs in natural sources of water but, so far, there have been no reported incidences of legionella in Qatar water. The consultative document produced by the British Health and Safety Executive in November 1990 recommended that the threat of this disease should be dealt with by a code of practice or regulations or a combination of the two.

The disease appears to be mainly demonstrated in wet cooling tower systems and, as no properly installed and maintained system is thought to have been responsible for any difficulty, the general trend has been toward dealing with the issue by codes of practice rather than by regulation. Despite this, there are significant commercial initiatives to make products which are claimed to improve the risk of legionella in water systems. These designs are based upon the fact that legionella pneumophila can not survive at high water temperatures.

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Temperature thresholds


Temperature

Activity level

 
20°c No growth of legionella (dormant)
37°c Legionella multiplies rapidly
46°c Multiplication ceases
50°c Legionella can survive up to one hour
60°c Legionella can survive from three to five minutes
70°c Legionella is killed almost instantaneously

Despite this, it should be noted that many commercial units have devices which limit the temperature of water to 43°c – the temperature which was recommended by the Kingston General Hospital study following an outbreak there in 1979, and accepted by the DHSS Health and Safety Executive.

There are several principles which should be considered when installing a plumbing system that will resist the introduction and multiplying of legionella.

  • Reduce storage capacity. Water should not be permitted to stand for long periods as stagnation allows contamination with particulate matter settling out and creating the nutrients needed by the bacilli to colonise.
  • Filters will help reduce suspended particulate matter.
  • Ensure filters are readily accessible and periodically maintained.
  • Cold water should be stored and circulated at less than 20oc and, preferably, below 15°c. Consider routing and insulation to prevent heat gain.
  • Hot water should be heated and circulated at between 50°c and 60°c in order to kill off the bacilli.
  • Additionally or alternatively more localised heating systems might be introduced. Low water content high output heaters and plate heat exchangers are now commonly being produced.
  • Introduce secondary return pipework in order to avoid stagnation. To reduce energy consumption microbore pipework could be considered. 08. Keep final hot water connections as short as possible – preferably less than 300 mm.

It has to be borne in mind that Legionnaire’s disease is transmitted through contaminated spray. It is not only found in domestic water systems but can exist in ventilating and air-conditioning systems.

The human being is used to having control over his immediate environment and, in modern Qatari houses, much of his choice is made for him. We are used to experiencing varying quality and quantity in lighting, temperature and air volume over the body. Modern designs have aimed to improve and standardise in an attempt to create a ‘better’ environment and, in doing this, have taken away from the occupant of the building a range of controls in order that the technical elements of the building should function more efficiently. Within the necessarily controlled environment of a Qatari house, the controls of lighting, heating, cooling and ventilation must be addressed not only in the overall design of the building, but in the controls for the occupants within each space within the building.

There is evidence that the effective control of the environment in domestic buildings may not be far off, although there is concern that the increasing sophistication of the control systems has not been matched by a proper understanding of how building managers might best use the systems, and there is a feeling that the use of such systems for domestic buildings may be some way off. Computerised systems are increasing in sophistication in response to market opportunities. If these trends to control the various elements affecting the climate within buildings continues there is little doubt that such systems will be sought after for domestic housing, particularly in countries such as Qatar where the use of conditioners of one sort or another are considered to be not a choice but a necessity. However, the lack of real concern about global environmental difficulties will continue to hamper the adaptation of such systems to domestic use in the Middle East.

The systems which are now being developed normally comprise a central user interface, communication network and data acquisition equipment, and these systems at present are common to non-domestic buildings. Concern within the industry has seen the development of a Building Automation system model at the Building Research Establishment. The Building Management System they are developing suggests that an intelligent building incorporates a system which incorporates a self-learning facility giving maximum control; individual controls which communicate with each other in order to improve the overall performance of the system; and an efficient method of informing users what is going on within the system, why and suggesting appropriate action.

At the least such a system should be able to incorporate the clients’ standards, monitor the relevant data for each space and function, maintain the clients’ requirements, identify problems, report on problems and advise on remedies. Some of the requirements would be built into the system prior to purchase – obviously the effective range of the equipment will require this, but the client must be able to comprehend easily his ability and scope to control the environment within his building.

A model for controlling conditions within domestic buildings might be envisaged which would:

  • Establish standards for spaces within the building
    • Set upper and lower limits for each space
      • temperatures
      • humidities
      • air changes
  • Establish utilities standards
    • Set upper and lower limits for
      • domestic hot water temperatures
        • baths
        • showers
        • wash hand basins
      • domestic cold water temperatures
      • drinking water temperature
  • Establish conditions likely to affect the internal comfort of rooms
    • solar path and its affect on the building envelope through
      • the day
      • walls
        • solid
        • glazed
      • roof
  • Predict performance for each space through 24 hour cycle
  • Monitor spaces
    • temperatures
    • humidities
    • air changes
  • Monitor supplies
    • domestic hot water temperatures
      • baths
      • showers
      • wash hand basins
    • domestic cold water temperatures
    • drinking water temperature
  • Monitor systems
    • air temperatures
    • air handling volumes
    • humidities
    • water temperatures
  • Compare with established standards
  • Assess acceptability
  • Diagnose systems’ conditions
  • Identify any problems
  • Bring problems to the clients’ attention
  • Determine causes of problems
  • Evaluate impact of problems on future performance
  • Advise on remedies
  • Act on instructions

In order to ensure that domestic buildings incorporate a suitably designed environment, many assumptions will have to be changed. In addition to the revisions to the design of the building and the need for building energy management systems to become commonplace, other elements of current services thinking will have to be re-examined. For instance, variable mechanical ventilation might become more generous; heat recovery to control condensation extended; ventilation air to be re-cycled; variable speed hydraulic circulating pumps; better control of air humidity, and so on. In addition to an increasing cost of utilities to the users, it is the building management system which is likely to bring home to them the need to improve the performance of the services under its control as the design input for these services is normally not within their supervision.

Such a system should be capable of recording essential data, if required by the client, and it is also possible that there will be other systems which would benefit from being monitored and integrated into the Building Management System. These might include, but not be limited to:

  • Monitor electricity to the site
    • quantity
    • stability
  • Monitor water to the site
    • quantity
    • pressure

Other utilities and systems might be separately considered:

  • Security
    • peripheral
    • internal
  • Communications
    • telephones
    • video
    • audio-visual
  • Cleaning
    • internal
    • external
  • Refuse
    • organic
    • inorganic
    • recycling
  • Supplies to the garden areas
    • water
    • lighting
    • sound systems
    • fertilisers

From the foregoing it can be seen that there is a direct relationship between the conditions obtaining inside and outside a building – in the case of this study, a residential building. It is at the interface that much can be done to deal with the problems of creating comfortable conditions for the user of the building and its plot. The skin of the building – its materials, construction, adjacent materials and the manner in which air is brought into and directed out of the building – is crucial to the effectiveness of comfort control.

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Planting

Rarely are landscape designers employed on a project in its initial stages, and with the scope and similar levels of responsibility to that of the project designer. Even in the West landscaping is often seen as an exercise carried out after the important decisions on planning and architectural design have been settled. Little attention is given by designers to the integration of landscaping into their projects. Yet, there is a strong case, aesthetically, psychologically and practically to consider planting at the same time that decisions on the uses, orientation, massing and materials of a project are made. The proper use of planting will have a significant bearing on the response the building is able to make within a specific environment as well as that of its occupants to their general and specific environments. This is particularly so for building in the harsh environments of the Gulf.

As has been mentioned elsewhere, there has been considerable integration of planting into Islamic developments over a period of time. This planting has usually been located in a manner which not only reinforces the manner in which the Muslim views nature, but also constitutes a practical vocabulary for developing responses to the aggressive climate of the Middle East.

In Qatar towns were not as well developed as those of the more prosperous northern Islamic countries, and were not able to demonstrate much more than a few specimen trees within a housing courtyard; but the fact that there was planting at all demonstrates that the aesthetic and practical principles embodied in planting were understood. Outside the towns, where there were areas of rawdha soils suitable for cultivation, houses were related more suitably to the planting.

In the desert, areas of cultivation normally had peripheral planting of trees to protect the crops, and housing associated with the cultivation would also be able to take advantage of the relief from the prevailing shamal.

The soils most commonly found over Qatar are relatively shallow, 10-30 cms. being typical. These are a calcareous sand loam, covered with rock debris, overlying a layer of rock fragments over limestone bedrock. In addition to this, over the country there are a little less than two thousand depressions which contain colluvial soils made up of calcareous loam, sandy loam and sandy clay loams to depths of between 30-150 cms. Generally these soils are known as rawdha and are the main source for the agriculture of the country. A third character of soil is the sabkha which is located around the littoral of Qatar and has been formed by wind driven soils filling shallow areas of the sea.

The nature of the rawdha soils is unfortunate in that they have only a small amount of organic matter, low water retention properties and poor structural properties. This gives rise to surface crusting which interferes with the plant-air-water relationship and inhibits the emergence of seedlings. Water generally available for irrigation contains between 1,000 and 2,000 ppm of total dissolved solids and this discourages filtration and leaching, causing the soil to become saline rapidly. This, together with the inundation of saline water into the underlying aquifers and the unauthorised extraction of increasing amounts of water from these aquifers, is increasing the problems of landscaping the peninsula. Generally, fertility is low with respect to nitrogen and phosphorous, and the soils are also deficient of iron, manganese and zinc.

Although there is little to be seen in the desert it is surprising what can be seen in the winter months, particularly when there have been sufficient rains to bring out the dormant plants. Six types of plant community have been identified in the peninsula. These community types are:

  • coastal sabkha,
  • coastal sand,
  • rawdha depression,
  • sand dune,
  • acacia tortillis, and
  • zizyphus nummularia.

The plant communities of the coastal sabkhas and sand are mainly halophytes:

  • halopeplis perfoliata, and
  • zygophyllum coccineum.

The rawdha communities contain mixed and pure stands of

  • acacia tortillissamr,
  • zizyphus nummulariasidr, and
  • lycium shawiiawasij.

Interestingly, the aeolian sands, which are greater in the south of the peninsula than the north, have affected the storm water run-off and permitted a denser incidence of these plants with fagonia indicaas ground cover.

There are notes on species selection on the Islamic garden page.

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Relationship with planting

Notes on planting have been made on a number of pages, but it might be useful to add a note here as there is a direct relationship between planting and environmental control that is not as well considered as it might be. Leaving aside the psychological benefits of planting, the essential beneficial characteristics of plants lies in their shade and transpirational qualities. Both of these can have a marked effect not just on people, but also on buildings and built elements of the environment around which people live and move.

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Shading

There are many references in Arabic and Persian literature to plants and their benefits, particularly trees. While much of this may be romantic, there is certainly an understanding of the relief and comfort plants, particularly, trees may bring in their shade. Not only are trees and shrubs useful in protecting people from the sun and, to some extent, the wind, they are also effective in moderating the environmental response of buildings.

At its simplest, trees can shade buildings, preventing or moderating the sun from striking window openings and so inhibiting solar gain within buildings. Deciduous trees have the added advantage of providing foliage to screen the sun in summer months, while in winter their bare branches permit the sun to pass through and into window openings, thus allowing the warming of a building.

The selection of plants, whether trees or shrubs, is important in consideration of the provision for the shading of buildings, as is their positioning. The closer to windows, the more likely a plant is to be able to provide shade. Flowers, creepers, bushes and the like can provide shade to windows by planting them close to windows, window boxes or planters being a sensible design addition for a number of reasons. Plants can also be trained up solar screens, or screens providing privacy for the occupants of a building.

Locating shrubs near openings can also help in cooling an interior as air, moving through the shrub will be cooled as well as slowed in its motion, producing a cooler, lighter breeze within the building.

With regard to trees, it is important to consider their growth pattern and select those that will be effective when they have reached a certain degree of maturity. The other considerations relate to the distance to plant from a building – the nearer, the more likely there may be a problem with roots damaging foundations – and location with regard to the orientation and positioning of the building.

Alternative shade patterns from different sun heights with a eucalyptus tree Alternative shade patterns from different sun heights with palm tree

These two crude diagrams are intended to illustrate, with a eucalyptus and palm tree respectively and of similar heights, the relative shapes and effect of the trees’ shadows in relation to an opening in the building. Firstly, it is evident that the lower sun casts a longer shadow and that, with a tree with foliage higher than its width, this will be more effective in protecting the opening.

The converse of this suggestion is that tree shadows are more effective when the sun is lower in the sky for the deciduous tree – by implication morning, evening and winter – and that they are less effective in the middle of the day unless the tree is planted very close to the building. The difficulty with this is that it is extremely difficult to provide cover for the whole of the day unless a number of trees are planted side by side.

Trees are living organisms, and each species changes its shape and size with age and season. In addition to this, the shade of a tree moves across the surface of the ground and adjacent building, covering and uncovering as the sun travels. It follows that, in order to provide shade for a specific opening, either the tree will have to be able to cover the opening for the times when the interior of the building is at worst risk, or more than one tree will need to be planted in order to provide continual cover during this time. Another way to deal with this issue is to provide shade only for a certain period of the day or to provide more than a single system to give optimal cover. For instance, trees for the latter part of the day, and a natural or artificial screen that would be effective for the early part of the day – or vice versa.

There are significant differences in the apparent path of the sun across the sky, not just over the period of the day, but also with regard to its path through the year. While we all have experience and a general understanding of this, we do not necessarily understand how marked this can be, nor how we may benefit from this understanding in designing the elements that surround buildings, most usually the landscaping and ancillary buildings.

Shadow path in summer from 6.00 am to 6.00 pm Shadow path in winter from 8.00 am to 5.00 pm

These two diagrams illustrate the shadows cast by the path of the sun through the sky on the 1st June and the 1st January in Doha, with the shadows thrown by a notional sphere, four metres off the ground and six metres in diameter. The shadows have been amalgamated on the diagrams and, for simplicity, have been taken on the hour. The Summer path is marked from 6.00 am to 6.00 pm, and the Winter path from 8 am to 5 pm. Both illustrations are looking at the sphere from the north.

The first point to note is that in summer, the sun rises and sets north of east and west, and its path is higher in the sky. As a consequence, much of the shadow falls south of the east-west axis at the hottest part of the year. In winter, the sun rises and falls south of east and west, and is in the sky a shorter period than in summer. All the shadow falls north of the east-west axis and this is true for most of the year, despite what is demonstrated in the middle of summer.

As I have mentioned elsewhere, the worst solar loading of buildings comes in the afternoons when the ground and buildings have had time to warm up. Although it might be thought sensible to guard windows facing east – in fact many textbooks dictate it – experience is that the emphasis for protecting openings should be from the sun as it falls in the afternoons, the south-west and west orientations being the most sensibly requiring protection from solar gain. This is also true of the building fabric generally. Heavy materials store solar energy, giving it up slowly in the form of low wave radiation both inside and outside buildings where there is no insulation.

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Transpiration

Transpiration is the process by which plants lose water to the atmosphere. This is carried out not just through their leaves, but also through their flowers, stems and roots. The process is complex but at its simplest, plants take in sustenance through their root systems in the form of water that carries nutrients. The evaporation of water from the plant results in a negative hydrostatic flow which draws the nutrients up the plant to its extremities. Coincidentally the process cools the plant and increases humidity in its immediate vicinity.

The quantities of water lost by plants differ greatly. Those that have evolved in desert conditions are notably different from those in cold or humid regions of the world in this regard, their appearance reflecting this in their character and form. Desert plants tend to retain moisture and are designed to minimise transpiration through a variety of evolutionary mechanisms. Cacti are, perhaps, the most easily recognised adaptation of the need to retain moisture.

In countries such as Qatar, the large quantities of water used to maintain plants masks the suitability of many plants to their environment. The water that is poured onto them moves through their systems and into the atmosphere, large plants such as trees commonly giving up hundreds of gallons of water into the atmosphere, though this depends upon a number of factors, particularly relative humidity. The higher the humidity, the less will evaporate. This transpiration, together with a proportion of the water poured onto them, creates a higher degree of humidity in their immediate environment, one that can be marginally beneficial to people in their immediate vicinity, but more so to other plants that will benefit from the micro-climate created by the larger plants. In fact, in some parts of the Middle East, Iraq, for instance, plants are grown together, sometimes in different ownership, each providing beneficial conditions for those growing below their canopies.

The amount of water given off depends on a number of factors, the most important of them being relative humidity, light, sunlight, air and windspeed, temperature, soil humidity and plant type. Note that, apart from soil humidity and plant type, these are also factors in the comfort of humans.

While moisture evaporates to the atmosphere and, in doing so, cools the leaves, it is important not to damage the plant by the action of water on the leaves burning them. This is one of the reasons why the natural process of drawing moisture into the plant from a trickle irrigation system below the surface of the ground it preferable to watering the plant directly from a hosepipe, for instance, and why it is also preferable to water after the sun has gone down when the water will have a chance to settle into the soil. More has been written about this on the page dealing with gardens.

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Health

With both electricity and water it is notable that there are difficulties associated with the demands of the users. The problems of the waste of resources by over-use of water and electricity have been mentioned elsewhere, but there has developed a requirement for an air-conditioned environment which can be positively unhealthy.

The body generally responds best to temperatures which are as constant as practicable: where there are as few dramatic changes as possible in temperature or humidity during the course of the day. In the past this was easily catered for by the smaller and gentler range of temperatures to which the body would be subjected to in the winter or summer. People then were more accustomed to dealing with temperature differences and it can be argued that there were less pressures on them.

It may not have been as comfortable as present circumstances allow but, nowadays, many users require extremely cold temperatures in their buildings during the summer months, which causes the body to be subjected to regular, dramatic adjustments as it moves to and from internal and external environments. It is perhaps not surprising that many people suffer from respiratory ailments in the summer.

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Climate

Qatar enjoys a maritime desert climate. Although the country is not large, this climate differs considerably between the inland areas of the state and the littoral areas where the majority of the important towns, including the capital, Doha, are located. Traditionally there have been a number of passive devices used to maintain or provide conditions of comfort within housing and neighbourhoods, but not all of them have been used in Qatar.

Doha Port is situated on latitude 25° 17.75’N and on longitude 51° 33.06’E, and it is from here and the airport a kilometre away, and near the coast, that the meteorological information available on Qatar is substantially drawn. The airport at Doha has maintained climatic records for a long time and is the usual source for accurate figures. I have taken these mainly from here, though I have added figures from other sources in order to give a relatively rounded picture of the climate. Please treat them as indicative rather than literally correct. They relate solely to the capital, Doha, and are given here for you to obtain a rough understanding of their variation and range.

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Climatic information – over 20 years


 

Year

Jan.

Feb.

Mar.

Apr.

May

Jun.

Jul.

Aug.

Sep.

Oct.

Nov.

Dec.


Temperature


Max. °c 45 27 29 33 33 38 40 45 45 37 31 28 23
Min. °c 10 10 12 14 19 22 24 27 27 23 21 17 14
Av. °c   17 18 22 27 32 34 36 35 33 29 24 20
Highest recorded 48 32 33 39 43 47 48 47 48 46 42 39 32

Average rainfall


inches 3.2 0.6 0.8 0.6 0.5 0.2           0.1 0.5

Morning and evening average relative humidity


a.m. % 71 81 82 76 66 55 52 59 67 78 78 80 82
p.m. % 43 52 52 46 38 31 28 37 41 46 45 49 54

Average wind speed


m.p.h. 12 11 13 13 13 14 13 17 12 9 9 11 12

Temperatures are, as you would expect, higher in the afternoons than the mornings, and humidity higher in the morning than the afternoon.

Winds are generally from the north north-west and can bring dust. Winds are relatively constant but there is variation near the coast each day with onshore breezes moving in as the land mass warms up.

It is important to know that rainfall varies widely from place to place and year to year as it does in many parts of the world. There is heavier rainfall in the north than in the south, and the rain can fall extremely heavily, causing damage as well as localised flooding. There is occasional hail.

Qatar is categorised as enjoying a maritime desert climate and its weather is strongly influenced by its being a relatively small peninsular land mass joined to the Arabian peninsula at its southern end. In particular it should be noted that climatic conditions vary considerably between littoral and inland sites.

General character of the weather

In general Qatar enjoys four seasons of weather, though winter and summer – particularly the latter – are the periods that tend to characterise the weather which forms the basis of most building design responses. Although Qatar is believed to have a very hot and humid climate, the weather can be extremely pleasant much of the year.

December is considered by the Qataris to be the first month of winter. The air temperature decreases and remains in the mean below sea temperature, and the latter continues to fall. There is increasing cloud cover and occasional rain. Winds from the north-west occur on most days with strong gusts, dust haze and early morning fog. In this month Qatar experiences the least solar radiation.

January is normally the coldest month of the year. There are outbreaks of rain more often than not with associated thunderstorms and prevailing winds from the north-west. The mean monthly sea temperature reaches its lowest point of the year.

February sees the air temperature rise a little from that of January, particularly towards the end of the month, with occasional rainfall and thunderstorms.

March is the first month of spring with land and sea temperatures rising steadily. Frontal system weather disturbances can cause rapid drops in temperature and outbreaks of rain. Winds continue to prevail from the north-west.

April sees the temperatures rise steadily, particularly towards the end of the month, and there is an increasing difference of temperature between day and night. The frontal weather can continue into this month.

May is the first month of summer and is hot and very dry during the day time. Nights can still be moderately cool and there can be occasional heavy rain storms at the beginning of the month, though the end of the month is very sunny and dry. The prevailing winds from the north-west gather in strength, and the sea temperature rises rapidly through the month.

June is dry and very hot. The prevailing winds from the north-west can be violent, creating sand storms and dust haze. This is the windiest month with the longest days and greatest solar radiation. Sea temperatures continue to rise.

July has the highest mean air temperature of the year. Humidity is a little higher than in June, but some days are extremely dry, especially at the beginning of the month. There is little cloud and no significant rain. Winds are less strong but more variable than in June.

August is usually very hot and uncomfortable due to the increasing relative humidity. There is no significant cloud or rainfall. The winds blow more frequently from the north and east bringing moister air from the sea, and sea temperatures are at their annual maximum.

September sees the air and sea temperatures beginning to reduce although the humidity is relatively high. This is the least windy month of the year.

October is the first month of autumn with falling air temperatures, but increasing cloud cover and relative humidity. There are occasional outbreaks of rain and the winds are relatively light and of variable direction.

November sea and land temperatures continue to fall, cloud cover increases and there is some rain. Sea and land breezes are most pronounced in this month with the north-westerly winds becoming more established.

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Variations of the weather from the norm

Although these are the theoretical patterns there has been in the past years, at least, similar divergences from the norm as have been experienced in Europe and elsewhere around the world, perhaps as a result of the greenhouse effect which is thought to be the reason behind Europe's weather patterns. Nevertheless, the weather in Qatar is significantly hotter than Europe, winters are relatively cold, and precipitation is slight though sometimes being deposited within a very short time. It is also noticeable that there are significant differences between inland and littoral areas.

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Design approach

Elsewhere I’ve mentioned difficulties with modern design, particularly those relating to the unsuitable character of building design in relation to a variety of environmental considerations. For a long time there was little attempt to produce buildings that were designed to ameliorate harsh climatic conditions such as those associated with solar gain, ventilation, heavy rainfall and dust ingress. The lack of design skills and experience were, to some extent to blame, but there was – and still is – a desire to produce iconic buildings that paid, and pay, little attention to optimal orientation, shielding, insulation, integrated design planting and the like.

The position is slowly changing, though there is still a tendency in countries with significant gas and oil reserves to ignore issues that would conserve energy. Qatar has introduced recommendations, as have many of its neighbours, to reduce power loads and water consumption:

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Electricity conservation


  • Regularly maintain your air conditioners,
  • close all doors and windows and pull the curtains down when the ACs are on,
  • switch off the AC in unoccupied rooms,
  • don’t use the water heater in the summer,
  • adjust the air conditioner thermostat to 25°c – 77°f,
  • avoid using electrical appliances such as washing machines, irons, or vacuum cleaners during the following two peak periods: 1pm to 4pm and 10pm to 1am,
  • use daylight as much as possible to light your house and office,
  • thermal insulation reduces the level of energy consumption, which helps to minimise the problems caused by excessive loads of generators and distribution networks, and reduces its initial cost,
  • thermal insulation reduces the consumption of electrical energy up to 40% during the cooling process inside the building,
  • don’t use lights excessively or during day time, especially external lights, and note that
  • thermal insulation minimises AC usage and the load on AC cables and ducts. This helps to reduce the cost of power consumption and electromechanical items’ initial cost.

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Water conservation


  • Instead of washing dishes under a running tap, just fill the kitchen sink;
  • don’t let your children play with taps and hoses;
  • don’t let the water run when you brush your teeth or when washing your hands and face because most of it will be wasted;
  • don’t clean vegetables and fruits under a running tap. Use the kitchen sink stopper instead;
  • plant drought resistant trees and shrubs. Some beautiful plants thrive with very little water. Minimise grass, because grass consumes a lot of water;
  • check all your pipes for leaks. Even a small leak wastes large quantities of water. Have it fixed;
  • when washing clothes by hand, use a wash tub instead of a running tap. Use a washing machine for full loads only;
  • don’t leave the hose open to clean your floors, use a mop and a bucket;
  • don’t use a hose to wash the car. A bucket of water is quite adequate;
  • water during the cool parts of the day. Early morning or evening; and
  • only water your lawn when it needs it, water just long enough for the water to seep down its roots. Frequent light sprinkling is wasteful.

Note that the above are advisory in tone, not mandatory

Since writing the above, Law No. 28 of 2008 was passed making it an offence to use drinking water to wash vehicles or to clean open areas in front of buildings. Cars may now only be washed in car wash or service stations. The law also creates fines for those permitting water to leak wastefully as well as those who have external lighting on between the hours of 7.00am and 4.00pm. It is apparent that Kahramaa will be tasked with attempting to reduce the waste of electricity and water, though there is comment in the press about how effective the inspectorate will be.

One final issue I should mention is the character of the climate in terms of theoretical design accommodation. Qatar has a humid, maritime, desert climate. It’s hot and humid. This suggests that passive environmental controls are best accommodated with open buildings permitting the flow through them in order to cool them. This, of course, is completely antithetical to the use of air-conditioning. Here is the present dilemma.

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Passive controls

As I mentioned above, there are three elements that need to be considered in dealing with the control of comfort. They also are the elements that will be manipulated in organising and designing buildings:

  • relative humidity,
  • temperature, and
  • air flow.

A number of organisations are attempting to come to terms both with the problems created by diminishing energy sources and by pollution. In addition they are beginning the process of educating clients to these problems in order to produce more environmentally benign buildings. The most useful products of these initiatives are those which begin to identify the issues that must be addressed on the effects of energy use on the environment.

There are may ways of structuring considerations; one such recommendation sets out nine key issues:

  • siting and orientation,
  • built form,
  • internal environment,
  • means of ventilation,
  • lighting and daylight,
  • insulation levels,
  • controls,
  • fuel choice, and
  • targeting, monitoring and maintenance.

To this might be added – or broken out, the

  • building envelope – roof and wall,
  • fenestration – windows and doors,
  • building materials, and
  • landscaping.

Although recommendations such as this are designed for the United Kingdom, they also make sense for situations in other parts of the world, such as the Gulf, although some recommendations have to be considered in the light of practice and capability within the area. Recommendations include the need to:

  • orient the building to maximise solar gain in winter,
  • use shallow plan forms to maximise opportunities for daylighting, natural ventilation and cooling,
  • provide solar protection in summer,
  • provide automatic lighting control and low energy lamps,
  • superinsulate the building fabric using CFC free insulation and multiple glazing units, and
  • select plant and equipment of the highest energy efficiency.

In addition it is useful to incorporate mass into the buildings in order to level out loading and reduce peak demands for air and chilled water systems. In sustainable energy terms there has to be a trade-off here between the environmental costs of incorporating large amounts of concrete into a structure with the reduced loading enabled by the heavy massed materials. Other devices to reduce solar loading might be incorporated into building design. I have previously suggested reflective materials – with the proviso that any reflection should not cause danger or nuisance to people and planting, or additional loading on other buildings – should be considered on building surfaces. Another method suited to roofs is the incorporation of thick levels of gravel to reduce solar loadings and there appears to be an opportunity for exchange mechanisms operating in gravel, water or manufactured units located on roofs. As an aside, many domestic buildings in the Gulf have a part of their roofs covered in light fabrics which serve a dual purpose; the fabric cuts down solar loading on the roof surface, and the air gap between fabric and roof encourages air movement, further cooling both roof and anybody using the roof.

To the above should be added issues that I believe important, which are local to the region, and which might not be considered to the same extent outside it:

  • ultra-violet component of the sun’s radiation,
  • allergens local to the area and, particularly,
  • issues relating to dust.

There are known to be problems associated with air-conditioned buildings. No significant work has been carried out on residential buildings although its known that there are a number of problems with offices. However, the main problems associated with air-conditioning is now realised to be the release of chlorofluorocarbons into the atmosphere, their effect upon the ozone layer and the consequential effects upon global weather patterns and individuals through increased levels of ultra-violet radiation. The chief problem facing Qatar and other Gulf States is in reducing the amounts of air-conditioning required by building users.

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Calculation for the provision of heating and cooling residential properties


Assume area of residential plot is 1,225 sq.m.
Assume area of house Minimum 350 sq.m.
Maximum 612 sq.m.
Assume ceiling height is 2.75 metres
Volume of house Minimum  350 x 2.75 =    962.5 cu.m.
Maximum 612 x 2.75 = 1,683.0 cu.m.
Assume: Winter heating levels 18°c to 24°c
Summer cooling levels 18°c to 24°c

What follows is an attempt to discuss briefly the issues raised above. One of the problems here is that it is difficult to compartment them logically, as you will find…

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Solar characteristics

The sun and moon are very important influences on the life of Qataris. The sun is probably the most significant element in the climate enjoyed in Qatar. Daily its effect can be seen on the way people behave, and an understanding of its effects is necessary for all designers.

The path described by the sun through the year is readily understood. At its zenith in summer, the sun rises and sets just north of east and west and, at mid-day is almost overhead. The rate at which it rises and falls appears to be fast and, when there is little dust in the atmosphere to act as a diffuser to the light source, the rate at which daylight appears or disappears can be extremely fast giving none of the slow dusks or dawns to which Europeans are accustomed. In winter, as in Europe, the sun rises and sets south of east and west and describes a much flatter trajectory within the southern sky. This period tends to coincide with there being increased cloud cover when the lighting effect can be more diffused and similar to Europe.

Solar path through the year

This diagram illustrates the different paths the sun describes as it moves across the sky during the year. The sun is at its highest on the summer solstice – 21st June, lowest on the winter solstice – 21st December, and on the median path for the autumnal and vernal equinoxes – 21st March and the 23rd September. The sun’s paths are set against a notional building arranged with its longest side on an east-west axis.

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Orientation and solar loading

You can see on the urban design page that there is little consideration of orientation in the disposition of most buildings. In a relatively flat country it can be argued that there are not the views that many might like to enjoy, though there are certainly views near the sea. But views are only one of the factors for influencing the orientation of a building. In hot climates, solar loading must be a strong consideration.

One of the few benefits in the urban planning of the roads are that many are laid out on a north-south, east-west axis. The advantage this has is that it can be used to optimise the solar load on the building. In theory, the optimal solar loading on a building occurs when its plan form is long in one direction, and that axis aligns with the east-west compass points.

In practical terms, as we all know, this means that the sun rises earliest in the morning – and sets latest – in the middle of summer, and rises latest – and sets earliest – in the middle of winter. It also rises and sets in different positions on the horizon describing a varied path across the sky through the year’s cycle, for which design decisions must be taken to deal with the problems and benefits this brings.

With a building, predominantly long along its east-west axis, the solar loading is theoretically improved. But this has to be associated with other design thinking in order to give full benefit to those who live in and around the building.

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Built form

It will be a benefit to the solar loading of the building if the amount of external envelope is minimised or, better, optimised with regard to the sun’s path during the summer months. Having said that, it is also beneficial if the sun can be used to warm the building during the cold, winter months. Manipulation of the envelope introduces more conflicting design parameters, one of the joys of the designer…

The basic principle to be remembered is to

  • minimise solar gain, and
  • maximise heat dissipation.

In winter, of course, this should be to

  • maximise solar and other source of heat gain, and
  • minimise heat dissipation.

So, the smaller the external envelope, the less heat will be picked up by the building. This parameter can be affected or modified by:

  • orientation,
  • modelling or three-dimensional form variation,
  • floor heights and depths,
  • the degree of fenestration, and the
  • protection and shading of,
    • the building, and
    • openings,

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Façade management systems

It appears that one of the keys to reducing the loads on buildings is to develop building elements outside the building that will modify the effect of the natural elements upon it. These can either be permanent elements of the building such as balconies, brises soleil and the like, or fittings such as curtains, blinds and awnings, and these latter elements can be manually or dynamically operated. Both elements have a design impact on the building, though architects tend to forget the effect of blinds and awnings, sometimes treating them in the same way they treat mechanical plant on roofs, balconies and walls.

However there are significant benefits to using external systems. One of the chief ones is that dynamic façade systems can pay for their incorporation within a very short time period.

The difficulty with operating façade systems is in determining the extent to which they should be manually or dynamically operated. Manually operated systems rely on

  • their presence,
  • the building populations’ awareness, and
  • the populations’ will

in order to have the building controlled effectively. Not only do these three factors differ in extent and understanding, but there is often conflict within any particular building governing their use. For this reason dynamic façade systems tend to be preferred and there is considerable benefit to the building from their incorporation. The main difficulty in achieving their effective use is organising a sensible interface between automatic and manual controls as few people seem to share the same taste in controlling temperatures, humidity and air movement. If those using a building can be governed by relatively simple choices giving them the comfort and temperatures with which they are happy, then significant savings can be made in operating the building through its annual and daily cycles.

A final consideration relating to façade systems is that relating to glare. Within an internal room there is likely to be unusually wide variations in light levels where there is no glare protection to external windows. With glare controls much higher comfort and use levels can be obtained.

The point of this has much to do with people being comfortable and happy in their internal environment. When people are comfortable in their building they should be more productive, and the operation comprising the building and its internal operation will be more economic.

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Solar protection

type and reason

Reflective glass – nuisance and possible danger to site users, neighbours and passers-by.

10°c difference between whitewashed and plain roof. Articulated architectural features increase the area of material available for solar radiation heat gain.

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Internal environment

space values, ventilation, lighting, psychological requirements, controls

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Lighting control

The control of lighting in Qatari buildings is approached slightly differently from the way it is considered generally in the West. There are three reasons for this:

  • cultural habits,
  • environmental issues, and
  • building types which, partly, are a reflection of the environmental issues.

Each has to be understood separately and jointly in order for designers to be able to develop vocabularies which respond to the particular conditions obtaining in Qatar.

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Daylight, sunlight and artificial light

Most Qatari houses require constant internal lighting due to the character of natural light and insistence upon privacy with externally orientated buildings. This wasn’t a problem with traditional buildings due to orientation and the lack of need for high levels of illumination. Nowadays the incorporation of low lux efficient lamps should be considered in all houses as background illumination with task lighting where needed.

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Daylight

The character of daylight in Qatar is different from the understanding of many Western designers. They tend to assume that the majority of light comes from direct sunlight as there is little cloud cover – except in the winter months, of course.

As a general rule it is important to understand that, much more so than in Europe, lighting comes from two sources created by the sun. Firstly there is that component which comes directly from the sun and is extremely aggressive and direct. The second is that from diffused sources. As stated earlier, in winter this is often from cloud cover acting as a diffuser of the solar source but, for much of the year, the main source of diffusion is from the dust and pollution in the air which is mainly situated relatively low on the horizon. The two lighting components for the working day are, therefore, situated in vertically different parts of the sky, and a particular characteristic of Qatar skies is the small amount of usable light which penetrates a normal building. The light which enters a window generally has a very strong horizontal component as it comes from the secondary source close to the horizon. In the past this was not so important as there were few activities in the house which required light to fall on a place at or close to the horizontal.

Notional illustration of lighting and its relationship with clouds in the atmosphere

This first diagram illustrates how daylight is generated in those winter months, a system which is similar to that which operates in the more cloudy atmospheres in the West. The clouds which generally cover most of the sky are illuminated by the sun and become a secondary source of illumination. This can be perceived as being similar to the manner in which a pearl light bulb works when compared with a clear light bulb. This light effect produces an even illumination both from above and from the side, creating a more or less regular and evenly distributed daylighting source, one which is free of the glare associated with sunlight.

Notional illustration of visibility and its relation to dust in the atmosphere

This second diagram illustrates what happens in Qatar during the summer months. The first thing to remember is that there is nearly always considerable dust in the atmosphere, the larger particles hanging lowest in the air. Indeed new arrivals in the area are often surprised when they see the results of their first photographs to discover how little blue sky there is. Looking directly up the sky is certainly blue; looking towards the horizons there is a clear sand-coloured haze. This aerial pollution acts in a similar manner to the clouds described above. Illuminated by the sun they act as a secondary source of daylighting. In real terms they are the primary method of illuminating buildings: useful illumination arrives horizontally within a room rather than vertically or at an angle. The corollary to this is that there is a useful form of daylighting; and it needs to be understood to be used appropriately and well.

Traditionally manipulation of the daylight was effected by using floors or walls to reflect and bend the light. Today, with the dramatically increased requirement to read and write – particularly for schoolchildren, as well as those carrying out sewing and tasks dependent on strong lighting, it is imperative that light should be made to fall with a strong vertical component. The standard treatment in modern Qatari houses is to employ artificial lighting, or to carry out the activity at the window, provided that the privacy of the individual is not compromised. But for daylighting to be effective in a room, it needs to be turned in order that the more usual activities which are carried out within buildings can be properly accomplished without the need for artificial light.

The direct light from the sun is a difficult but potentially useful source of lighting within buildings. In the summer months its direct presence within a building will cause two main difficulties: glare associated with the contrast between areas lit by the sun and those in shadow; and strong heat gain. A third, associated difficulty is damage caused to materials due to direct light or heat. However, in the winter months, there are a number of benefits to introducing the sun into a building. In particular these are: heat gain to the benefit of the user; additional illumination which can satisfy both a physical requirement for task lighting, and a psychological need for visual warmth.

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Glare

The dust and pollution within the atmosphere create another effect of which designers must be aware. Glare is a constant problem in Qatar as there is always dust suspended in the air. Looking at the horizon on any particular day it is possible to see the graded effect of this dust, the heavier particles being obviously nearer the ground. Light reflects from this dust and can be a constant source of irritation to the eyes, but it can also be utilised as a source for improving the light within buildings. Most text books state that buildings’ windows should be kept small to the south and opened up to the north. The effect of this is to ensure that the view which is being observed from south-facing windows – from a house this would normally be a two metre high boundary wall – is in constant shadow and not a source of reflected light.

Conversely, a large window in the north of a building usually looks out onto a wall or building which is in brilliant sunshine and is physically difficult to look at unless heavily planted. This can have the effect of appearing more restful to the eye, but may be a psychological effect created by viewing plants, movement or the colour green. However, there is still glare experienced by viewing to the north as the light, having its source behind the observer, reflects off the dust particles and into the eyes of the observer. On the other hand, viewing to the south with the sun in the same quadrant of the sky, the component of the light reflecting into the eyes is much smaller; a situation that is considerably more comfortable for the viewer.

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Reflection

The other characteristic of solar sourced lighting, of which designers should be specifically aware, is reflection. The sun’s reflection can be hazardous if coming off a highly reflecting surface. The sources of this type of reflection which are most commonly experienced in Qatar are glass and metal and can be extremely dangerous if not damaging. Designers should be aware of the effects within their buildings both from sources beyond the building and from within the elements which create the building and its surrounds. They should also be aware of the potential danger to others caused by their designs.

For instance, it is not uncommon for car drivers to be temporarily blinded at certain times of the day and year, and rooms can be dramatically illuminated for a short period of time. In addition it is possible to damage plants by locating them in position which receives a lot of reflected light. It is possible, of course, to use reflected light to advantage, but the moving character of the source of light – the sun – militates against a sensible design unless it is controlled by a moving reflector of the kind most commonly used on solar furnaces. The dangers inherent in this powerful source of lighting most probably rule out all but the most refined and, therefore, expensive design solutions.

The general point which can not be over-emphasised is that the sun, as a design consideration, must be constantly borne in mind when designing in Qatar.

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Moonlight

As is described elsewhere, the practice of Islam is closely associated with the lunar month, and the moon can be seen in the sky most of the year: a daily reminder of the phase of the month. Given the normal clarity of the night sky, moonlight can be a significant source of light, and there is often the ability to use it constructively, particularly in residential buildings where its relatively low luminosity may be beneficial.

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Sunlight

In addition to daylight there is the sun as a light source in summer, but this is more difficult to handle and is generally to be avoided as a light source at this time of year, though is ideally used as a source of energy.

That is not to say that the sun doesn’t have a place as a source of illumination. I have mentioned elsewhere the possibility of using light tubes for illumination, illustrating the concept with a type which is readily available commercially. But other designs are possible either used passively or even tracking the sun, though this brings with them difficulties attendant on the need to maintain moving parts: it must be remembered that dust and sand get everywhere in Qatar.

In addition to this there should be an obvious consideration for reflected light from the sun. The negative side of this is the need to avoid reflected sun causing problems, particularly burning plant material, shining in the eyes of drivers, or illuminating rooms directly. One of the problems associated with using the sun as a reflected source is the obvious one: it moves throughout the day.

In winter, of course, there is a good reason to have sunlight come into rooms to warm and give them life. At a lower angle the sun is not as dangerous as it is when high where it is moderated by atmospheric haze.

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Artificial light

I mentioned above the fact that, almost regardless of how natural lighting sources are used, there is likely to be a need for artificial lighting within buildings. This is due to a number of reasons.

Firstly, there are the physical factors associated with designing large rooms which have various forms of control on their window openings. Although the aim of moderating the entrance of light to the building should be paramount, there are conflicting requirements for security and privacy which are likely to reduce the amounts of light introduced to the room. A secondary reason associated with the design and planning of houses is that, due to the number of rooms there are often corridors or distribution spaces which have no direct lighting. In fact I have seen families using internal spaces by preference, and where there is no possibility of natural lighting.

Secondly, there is the prevailing character of interior design favoured locally. This tends to be visually heavy within the room and, even though colours favoured may often be light in tone, the textures tend to absorb light. But more than this, most windows are treated with hanging curtains. Even when these are not used properly, they are still likely to be dressed to partly cover the window opening, thus reducing both the light entering directly as well as masking the window jambs which are an extremely useful method of reflecting light into rooms.

A third factor is the habit of some to keep their curtains drawn all the time and use only artificial lighting. This may be the result of many designers creating houses having insufficient privacy for their inhabitants, and their obvious reaction in creating the privacy they require by drawing curtains.

There is a fourth factor and that has to do with the introduction of electricity to the country. I can’t tell the extent to which this is still a factor, or whether it has been subsumed within the foregoing points, but I’m aware that some people wanted to be able to use the new resource simply because it was available, and free.

So, the point to bear in mind is that some degree of artificial lighting is likely to be required within buildings during the daytime as well as at night. The colour temperature should be carefully considered with regard to the external colour of light in Qatar as well as the tasks the lighting has to cover. I shall look at the design implications elsewhere. This is particularly relevant today with the emphasis there is on changing to more suitable sources with which to light buildings.

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Wind

character and direction

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Ventilation

There are two forms of ventilation to consider, natural and mechanical – the former, passive, system being that traditionally used in the Gulf.

Traditional devices attempted to maintain comfort for the users of buildings by doing one or a combination of four things. They

  • sought to avoid heat gain by shading against the effects of the sun,
  • attempted to delay the effects of heat gain,
  • tried to lower temperature by increasing the air flow across the body, and
  • attempted to increase humidity in arid areas.

These systems differed depending upon the local conditions obtaining and the sophistication and wealth of the inhabitants.

The badgheer has been the traditional device designed to increase and direct air across the user of a space. In essence it consists of two parallel, vertical slabs offset from each other with a narrow gap between them through which air is channelled down from a prevailing breeze or wind. For this to work properly there must be a means for air to escape on the other side of the space.

The badgheer was usually employed at a relatively low level and worked by flushing the air over the ground either within a room or over a terrace. In this way not only would there have been cooling by the warmer air moving across the relatively cool, hard internal floor, but there would have been the benefit of air movement to those sitting inside the room where sitting was normally arranged peripherally around a room, and at floor level.

External terraces also employed the badgheer and here the benefit for the residents was to have the cooler night breezes drawn down onto the ground where they would sleep at night outside the rooms which would have become warm from the day’s radiation on the fabric of the building.

Wind scoops and wind towers were also developed in a number of areas of the Middle East. These were designed to bring wind or breezes down from a relatively high level into the close-packed development of the town where normal breezes were unable to penetrate. In this sense they were essentially ventilators but, with various amendments they were also capable of significant cooling. Wind scoops were normally designed to face only the prevailing wind and were not designed to be moved, although I have seen tented versions which were more readily re-oriented. Wind scoops are not as much of a feature in the Gulf as are the wind towers. The latter developed into quite considerable architectural structures and were mainly designed to accommodate wind directions from a number of sides, normally four. The tower in which they stand is usually square in plan, and is divided into four segments by an arrangement of septums which comprise the two diagonals of the square.

With a larger number of sides there was an increase in the structure’s ability to have an opening face a prevailing wind, but a concomitant decrease in the amount of wind that was able to penetrate the structure due to turbulence at the entrance to the tower. Within the Gulf the structures are virtually all of the four-sided version.

Three other factors which affected the working capability of the towers were the

  • cross-sectional area,
  • its relationship to the length of vertical passage for the wind, and
  • the size of the openings facing the wind.

These three factors were critical to establish the correct size for the prevailing conditions as sufficient air must move down the shafts with enough velocity to enable the air to be of use to the occupants. The shaft itself, slowly heated by the day’s sun, also acted as a chimney in periods when there was little or no wind, its warmth venting the warmer air from the space below it, drawing in cooler air from the spaces surrounding that space.

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Humidity

In arid regions the designers of houses attempted to ensure that there was moisture introduced into buildings for the comfort of the user. Qatar, enjoying a relatively humid maritime desert climate, did not need to, the problem within houses being to reduce humidity, not increase it. However, within the interior of the country, high humidity was not as great a problem as it was on the coast and the air could appear to be relatively humid.

The methods which were designed to increase humidity all had the same basic theory behind them: they led air across water prior to moving into the space which required humidifying. In the Alhambra air was led over areas conditioned by fountains, enabling the air to be humidified and cooled by evaporation before passing on.

The more usual form of humidifier was much simpler and varied from place to place. In Iran wind catchers might have a mat of rushes inserted in the opening and this would be soaked with water to give the desired effect; in Iraq low window openings had mats or bushes stuffed into them and water poured over them to give the same result. This also modified the light within the space and reduced the potential air loss from the relatively cool interior; in Egypt air was led across water moving over a carved slab of stone, shadirwan, onto which water was poured from a salsabil. Evaporative cooling of warm external air was also possible by leading the air over a cool slab of marble, as was done in some old Arabic houses, and a similar effect obtained by placing a porous pot of water in an opening on the windward side of a house, simultaneously lowering the temperature of the air and of the water in the pot. In simple desert houses in Qatar, cooling could be carried out by stuffing desert bushes into openings and pouring over them.

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Psychological factors

With Qatar’s humid maritime climate, it was important to reduce humidity rather than increase it though, as I have mentioned, inland and when humidity was low, an increase might have been seen as beneficial from time to time. I understand that, when there were relatively dry, driving winds, the physiological and psychological need for a degree of humidity might have been sought.

In addition to the above methods of actually increasing humidity when there is a necessity to do so, there were also psychologically effective refinements that evolved.

In most peoples’ minds the sound or sight of water is synonymous with increased comfort, particularly in dry lands. The fountain, as a natural element, was able to excel in that not only did it increase humidity but it also gave a strong visual display, sparkled in the light, and could be heard for some distance. Water courses, particularly those which employed devices to break up the flow, were also both aurally and visually significant in benefiting the building user. The shadirwan is an example of this, sparkling as the light caught the water moving across its carvings.

The paradox relating to the provision of fountains, waterfalls and the like to bolster the impression of coolness and peace is the fact that they are, in fact, humidifying the atmosphere.

Reinforcing the practical methods of reducing the effective temperature were a number of related factors which must have developed naturally and which helped the Arabs to feel comfortable. A particular consequence of heavy walls, small openings and shaded external areas is the feeling of sanctuary both from an oppressive climate and from a public life or, conversely, an emphasis on the privacy of the individual and the family. This connects directly with what I have described elsewhere, the central role of the household in the Muslim’s relationship with his religion.

I believe it was not accidental that the colours of the tilework in buildings are cool and that the repetitive geometrical shapes and patterns developed under Islam both in the planning and decoration of architecture encourage the quieter, contemplative character of the viewer and, in so doing, reinforce the feeling of coolness and peace. The use and integration of the natural elements of planting and water into buildings contributes in large measure to the tranquility and peaceful character of Islamic buildings.

The soothing colours, movement, sound and smell all contributed to relaxation and the feeling of comfort, as well as the plants providing a degree of physiological cooling through evapo-transpiration.

Air barriers and vapour retarders. Position of these dependent upon the internal/external relative conditions, but both obtain in Qatar.

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Air-borne impurities

Many people believe that the air in Qatar is clean and relatively pure. People of Bedu stock still enjoy the smell of the desert and it is not uncommon to find families, miles from a road, ‘drinking’ the air, as it is termed. The desert certainly has a taste or smell to it which differs as you would imagine, from place to place. But it is a clean feeling reinforced, when experienced at night, by the ability to see much of the night sky and its stars. By the same token urban areas have the problems with which we are familiar in the West – those associated with pollution from the obvious culprits. The reason why people of Bedu stock visit the desert is not just their love of the desert but to escape the smells of urban life.

The most common polluters are motor vehicles and light and heavy industrial processes. With regard to the latter, the State has always endeavoured to locate polluters or processes which have smells associated with them – such as sewage treatment and certain industrial activities – down wind or at some distance from existing or likely residential areas.

While most people will understand that some degree of pollution in public places is not uncommon, the insides of private house plots and, particularly, their interiors should be pollution-free.

  • those entering into the system through intakes etc.
  • those which are developed inside – stale air, cigarette smoke etc.
  • positive and negative ions – no evidence the latter is useful yet.
  • use of internal planting to make oxygen and reduce impurities
  • need to evaluate modern materials which cause physical disorders
  • formaldehydes etc.

There are two important materials which can cause problems and of which people are more likely to be aware:

  • allergens and, particularly,
  • dust.

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Allergens

types and reasons

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Dust control

To a greater or lesser extent, most countries have to deal with a certain amount of dust in the atmosphere, but it is a real issue in Qatar as it is in the region. Some think of it as a housekeeping function and, in the past, it was one of the problems which had to be put up with both in the desert and town. Today it is much more of a problem due to the increased value of the interiors of households and the desire of Qataris to have their houses looking good all the time. Having servants or extended family to carry out the house work helps, but it is difficult to explain to anybody who hasn’t experienced it, what effect dust has, particularly in the middle of a dust or sand storm.

The effects of a sand storm

The wind that scours the peninsula, the shamal, brings dust down the peninsula often, as mentioned below, from far away. Whatever the source, sand or dust storms can be extremely unpleasant as well as a danger to traffic. This photograph is a good illustration of the character of a storm, though bear in mind you can often see far less than this.

Dust gets everywhere. Its most obvious appearance is on horizontal surfaces but it also has a distinctive smell. It is difficult to seal a building against it as the size of the particles can be very small. When the level of atmospheric dust increases, there is nowhere the dust doesn’t go, with the potential for causing problems with much of the electronic equipment most owners own.

Dust can be taken to range in size from 0-50 microns, sand from about 60-2000 microns (two millimetres). The largest particles moved by the wind are in the region of ten millimetres, though these will bounce and not be capable of being picked up.

Elsewhere i have mentioned sand dunes and their movement, this movement caused by the prevailing wind, the shamal. Wind is the major factor in moving silts and sediments around. The peninsula can be very hot and, when there is no rain, winds move these materials over long distances depending, of course, on the size of the particles. The dunes are generally composed of the larger grains which roll and bounce along the desert floor, while the lighter grains and particles are taken into suspension and can travel significant distances. Sometimes, in Qatar, dust of a very different colour from the sands of the peninsula fall, having been brought hundreds of miles.

Fine dusts can be a nuisance if not a hazard at quite light wind speeds. Sometimes these dust hazes originate locally but often they are generated within the Arabian peninsula or as far away as Iraq. There may be little distinction between the two types. Wind speeds of as little as 45 km/hour can produce this haze; at 75 km/hour the haze becomes a hazard to aircraft as well as a serious nuisance at ground level.

The season for dust is late Spring and particularly early Summer as the soils begin to dry out and become mobile. September sees the beginnings of reduction of the haze with the increasing humidity and the start of the rains in the northern deserts. By November the dust will have virtually stopped.

Traditionally tents and houses both suffered from dust. The best that could be done to reduce its effect was to close the openings as efficiently as possible and wrap clothing tightly around, particularly the face and nose. Within compact urban areas there was a slightly better chance of avoiding the dust due to the action of the housing acting as a filter. But the dust still got through. One device that helped to reduce the amount of particulates that were drawn into the houses was a sand-trap at the bottom of the badgheer which collected the heavier particulates.

Nowadays there are essentially two ways of reducing sand and dust in buildings, though neither is perfect:

  • natural, through the use of vegetation, and
  • mechanical, through the use of settling tanks and a variety of equipment.

In a sense there have always been these two options available but, as you would expect, they were resolved in a simpler manner than they are today.

Planting on as large a scale as possible helps to bring dust particles down and acts as a filter for particulates in the air. Planting also helps to stabilise the ground, reducing the amount of material available for movement, both the heavier particles which bounce and roll along the ground as well as those likely to be drawn up and taken into suspension. The State has a policy of planting for recreational and amenity purposes.

Wind driven sand and dust encroaching onto the tarmac of a suburban Doha road

This photograph clearly illustrates how the sand and dust is blown onto roads creating a number of problems relating to signing, driving and drainage as well as being aesthetically unpleasant. Development along roads and in public parks helps in the general goal of reducing particles in the air and to some extent along the ground. This is supplemented by private planting both of which have some effect in cleaning the air. The State has also been responsible for planting in the desert, particularly along roads, and there have been traditional uses made of planting upwind of areas where people live and farm. This planting has been designed to bind what little topsoil there is and also to help fight the accretion and movement of sand in the form of dunes, protecting farming areas from inundation.

Wind tower wind flow

The most widely used mechanical device to reduce the amounts of sand coming into buildings was the burj al hawwa. Designed to introduce higher level air movement into dense urban areas, by its nature this was accomplished at the expense of also bringing dust and sand. In order to reduce the amount of particulates getting into the house there was an area at the bottom of the burj al hawwa which collected the sand and was separated from the circulation area of the house by a raised step. While this prevented the heavier particles from moving into the house it was not as effective in keeping out the lighter particles due to the wind speed within the system and the almost direct route the air was designed to take to into the houses.

Diagram of a sand trap

Where similar systems are used today they are not part of a system for bringing cooling breezes into buildings. Designs focus instead on slowing down the flow of air in order to allow it to release as much of the particles as is practicable, before moving the air through a relatively fine filter and on into the air-handling plant of the building. This produces a system that has optimal and manageable maintenance on it. In theory, as you will see from this diagrammatic representation, it is similar to the principles behind a petrol or grease trap.

Equipment designed to remove dust falls into four categories:

  • settling chambers, as illustrated above,
  • inertial dust separators,
  • mechanical filters, and
  • electro-filters.

Filters are not sieves and generally have apertures considerably larger than the material that passes through them. They rely upon slowing down the passage of air and its suspended particles, and allowing those particles to fall out of suspension onto collectors which may be constructed from a variety of materials.

Electro-filters gain their effectiveness by charging suspended material by means of a high voltage electric fields, causing them to be attracted by electrodes on which they are precipitated, releasing their charge.

Both types of filter are sensibly used in series with a settling chamber in order to clear the heaviest particles first.

Dust is a nuisance both psychologically as well as physically. Today there is less likelihood of building owners putting up with the discomfort of the amounts of dust associated with storms, and even less likelihood of their wanting to put their equipment and material goods at risk. Housing, and other buildings of course, should be properly weather-sealed not just from the ingress of water but also from dust. Bear in mind that dust can move in any direction in its attempt to enter buildings.

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Insulation

amounts and character

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Rain

character

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Effects of urban development

Much of what has been said so far relates to all buildings in Qatar, however there is a significant series of effects which are directly related to urbanisation and are consequently more relevant to the larger conurbations where it is anticipated that the majority of new housing will be located.

Urbanisation creates an effect that has been referred to as the city climate. Although research is not available for the peninsula, it is instructive to look at the effects measured in Europe to observe the pattern whilst understanding that, even in this case, the figures should be viewed with circumspection:

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Effects of urbanisation


Element

comparison with rural surroundings

Radiation global 2-10% less
ultra-violet – winter 30% less
ultra-violet – summer 5% less
sunshine duration 5-15% less
Temperature annual mean 1-2° more
sunshine days 2-6° more
greatest differences at night 11° more
Wind speed annual mean 10-20% less
calms 5-20% more
Relative humidity winter 2% less
summer 8-10% less
Precpitation total 5-30% more
Cloudiness cover 5-10% more
fog – winter 100% more
fog – summer 30% more
Contaminates condensation nuclei 10 times more
gaseous admixtures 5-25 times more

The rise in temperature is a function of the high proportion of secondary energy within the city, combined with the altered absorption circumstances and the slighter cooling effect.

Buildings and sealed surfaces possess a higher thermal capacity than the desert and, at night, give up their heat more slowly. The level of long wave heat radiation is increased in a dense urban situation by the reciprocal effect of reflection and absorbtion. In certain cases it is possible for individuals to feel sick from this effect.

Cooling effects in winter through evapotranspiration are mitigated by the loose density of most urban development, and because there are no bodies of water and little vegetation.

Wind velocity is difficult to gauge. Although urbanisation tends to lessen ground level velocities unless there is a channeling effect, it is fair to say that modern urbanisation slows down wind velocities generally, and buildings are not designed to lead breezes into courtyards or passageways as did earlier systems of development. It should also be noted that buildings produce more disturbance of wind patterns, often creating unusual wind effects.

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Monitoring and maintenance

manuals, values

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West Bay watering standards

The standards set out below were developed in order to obtain an initial estimate of the watering requirements for the New District of Doha. The units mix imperial and metric as that was the way it was done at the time, but I shall amend this later. The main concern was to find out what was needed to establish and maintain the landscaping of the area, and from there to determine the plant, equipment and personnel required to support the figures.

Please bear in mind that these were estimates at the time and that events have varied many of the figures.

Item


rate

rate per unit

Private housing


Senior Staff @ 1,500 sq.m 1.33 gals/sq.m/day 2,000 gals/day
Popular house @ 600 sq.m. 1.33 gals/sq.m/day 800 gals/day
Embassy residences @ 6,500 sq.m. 1.33 gals/sq.m/day 8,650 gals/day
Public gardens 1.25 gals/sq.m/day  

Roads


 

 

Corniche

   
median @ 15 m. grass 1.8/sq.m/day 27 gals/sq.m/day
4 rows trees @ 6 m. 11 gals/tree/day 7.3 gals/m/day
median shrubs 2 @ 3 m. 5 gals/shrub/day 3.4 gals/m/day
kerb @ 12 m.shrubs 4 @ 3 m. 5 gals/shrub/day 6.8 gals/m/day

Primary roads

   
median @ 15 m. grass 1.8/sq.m/day 27 gals/sq.m/day
4 rows trees @ 6 m. 11 gals/tree/day 7.3 gals/m/day
median shrubs 2 @ 3 m. 5 gals/shrub/day 3.4 gals/m/day
kerb @ 12 m.shrubs 4 @ 3 m. 5 gals/shrub/day 6.8 gals/m/day

Roundabouts

   
2,800 sq.m. grass 1.33 gals/sq.m/day 3,725 gals/day

Secondary roads

   
2 rows trees @ 6 m. 11 gals/tree/day 3.7 gals/m/day
kerb shrubs 2 @ 3 m. 5 gals/shrub/day 3.4 gals/m/day

Local access roads

   
  Similar to Secondary roads  

Culs-de-sac

   

   Senior Staff

   
3,875 sq.m. grass 1.33 gals/sq.m/day 5,150 gals/day
75 trees 11 gals/tree/day 825 gals/day
75 shrubs 5 gals/shrub/day 375 gals/day

   Popular housing

   
940 sq.m. grass 1.33 gals/sq.m/day 1,250 gals/day
20 trees 11 gals/tree/day 220 gals/day
20 shrubs 5 gals/shrub/day 100 gals/day

Schools


 

 

pitch 8,800 sq.m. grass 1.33 gals/sq.m/day 11,700 gals/day
peripheral trees 2 @ 6 m. 11 gals/tree/day 640 gals/day
school garden 3,000 sq.m grass 1.33 gals/sq.m/day 3,990 gals/day
50 trees 11 gals/tree/day 550 gals/day

 

The figures given above were looked at and amended slightly to give the following basic requirements for the various simplistic elements of the New District of Doha.

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Basic watering requirements


 

 

Private gardens

   
Qatari Senior Staff   2,500 gals/day
Popular house   1,000 gals/day
Embassy residences   8,400 gals/day
Public gardens 1.25 gals/sq.m./day  

Roads

   
Primary 57,500 gals/day/km  
Roundabouts 4,200 gals/day  
Corniche 73,300 gals/day/km  
Secondary 10,300 gals/day/km  
Local access 10,300 gals/day/km  
Culs-de-sac    
Senior Staff 7,330 gals/day  
Popular housing 1,460 gals/day  

Other

   
Schools 30,100 gals/day  
Pitches 13,250 gals/day  
Ministries 64,000 gals/day  
Hotel and Conference Centre 120,000 gals/day  
Embassies 4,300 gals/day  

 

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