Book - School of Science and Technology

20 The building in wintercoincide and, due possibly to a change in building use, these do not apply, then theheating system may well be undersized. In instances where, despite the last comment,some allowance is made, particular thought must be given to the needs of an intermittentlyheated building where a pre-occupancy boost may be required during the time whenno internal or solar gains are available.Past practice in design, for other than off-peak electrical heating systems, has been toignore the effect of such gains entirely in so far as calculations for the heat necessary tomaintain a given internal temperature are concerned. In calculations for energy consumptionand running costs per annum, however, the importance of these gains has beenbrought out by studies of actual fuel use in buildings. The case for adequate thermostaticcontrols is self evident.Conservation of energyThe past situation, when a seemingly limitless supply of fuels of one sort or another wasavailable has come to an end. In the new age which dawned following the `energy crisis' ofthe mid-1970s, economic forces have led to a startling rise in the cost of supplies, with theresult that many of the old standards of comparison no longer apply. The more recentstabilisation of fuel prices, largely brought about by the price of oil in the internationalmarket and the privatisation of the energy market in the United Kingdom, may beconsidered as no more than a temporary pause in the inevitable upward spiral of energycosts. Governments also have a role to play in energy conservation and the introductionof the climate change levy in April 2001 by imposing taxes on an organisation's energy billis an example of this.As a result of this situation, energy conservation in the sense of fuel saving is nowa doctrine of political importance as well as one of realism. In the context of this book,it has been estimated that between 40 and 50% of the national annual consumption ofprimary energy is used in services to buildings. By the introduction of sensible economymeasures, without real detriment to environmental standards or the quality of life, it ispossible to make significant savings in the context of heating and air-conditioningsystems. But the most dramatic attack upon energy consumption must come about as aresult of reconsideration of the building structure, readjustment of capital cost allocationsand improved maintenance of buildings and equipment.It follows that the first step in embarking upon the assessment of heat requirements fora building should be to ensure that they have been reduced to an economic minimum.This will involve collaboration between the architect and the building services engineer inconsideration of the building orientation, selection of materials, addition of thermalbarriers and reduction in window areas. Ideally, this collaboration should start at aneven earlier stage when the basic plan form of the building is being considered, bearing inmind that the major component of the total thermal load is through the perimetersurfaces.* In this sense, the most economical shape for maximum volume with minimumsurface area is a sphere and although this is hardly a practicable shape for a building, thenearer to it the better. A tall shallow slab building is obviously one of the worst in thisrespect.* Page, J. K., Energy Requirements for Buildings. Public Works Congress 1972.Jones, W. P., Designing Air-Conditioned Buildings to Minimise Energy Use. RIBA/IHVE Conference 1974.