| buy book | THE ARCHITECTURAL EXPRESSION OF ENVIRONMENTAL CONTROL SYSTEMS By George Baird. London: Spon. 2001 This is a very thorough book with a very clear analysis of environmental systems fully referenced. It is a good source of writing about the subject. In addition, a set of examples is analysed taken across the world without the nationalist bias which creeps into most writing on architecture. Considering that the book is written by a person who originally trained as an engineer, there are very few numbers. It is very difficult to reconcile measured energy consumptions with design predictions. I worked on an electrically heated block of flats in the ’60s. Three years’ worth of bills for 1000 flats could not differentiate between flats with gable walls and exposed roofs from flats completely enclosed by other flats. The calculated heat loads were different by a factor of two but the bills differed by a factor of six and the variables masked anything caused by the construction. I believe the lesson to be drawn from this observation is that the variables (for example ventilation) must be brought under control. It is important to have observations of energy consumption so that reality can be reconciled with design, and the design of new buildings can be improved. This is one of the important aspects of the PROBE studies which are often referred to. Nearly all the subject matter of the book covers buildings where people work. The key issue of providing natural light is not really covered. Where people work, electric light is usually designed to provide around 500 lux. Housing is different and not so difficult. Rooms are small and shallow and 50 to 100 lux can easily be provided by small openings. If 500 lux is to be provided by an overcast sky (5000 lux) there is a real design challenge which is most easily solved using roof lights. Then a blue sky (10 000 lux) still needs large openings. Full sun (100 000 lux) imposes a real penalty of heat gain. Openings designed to provide enough light under an overcast sky impose a heat loss penalty on a winter’s night. These issues are understood by paying attention to the measurements and predictions of energy use and that is why I am disappointed not to get a more quantitative approach written by a renegade engineer. The issue of natural lighting relates to much of the evolved architecture which is often referred to by George Baird. MAX FORDHAM |