The Cost Of Cool.
issue 319 - December 1999
Michael Peel reports on the rich
world’s love affair with conditioned air.
There is a chill in the air at Cannons gym, a favourite lunch-time haunt of City of London workers. The sports centre, plagued this year by soaring temperatures, has souped up its air-conditioning so much that at quiet times a session resembles a polar version of purgatory.
It is just one example of the casual over-use of air-conditioning apparent in the Western world. It has become a central feature of work and play, a prestige symbol of humanity’s ability to control the climate.
But the electricity air-conditioning systems burn up make them a significant and growing contributor to climate change. They are unpopular even with those they serve, most of whom prefer old-fashioned cooling methods such as opening windows and sitting in the shade.
Yet in Britain the use of air-conditioning is predicted to grow four-fold by 2020. Per-capita, the US is already drawing almost seven times that forecast, and Japan twice as much. In both countries, air-conditioning accounts for more than five per cent of the total electricity used in buildings.
These figures are far greater than they ought to be, says the Building Research Establishment (BRE), a consultancy formerly owned by the British Government. Many air-conditioned buildings could make far better use of other cooling methods. They could take advantage of daylight and natural ventilation, reduce glare and have thicker walls that absorb heat during the day and radiate it away at night. These measures may sound obvious, but they can yield telling results: the BRE has put up a prototype office building that uses 30 per cent less energy than the best of the present bunch.
While the project might attract environmentalists and companies looking to reduce running costs, it cuts less ice with developers. For them, the emphasis is on throwing up a building in the shortest time for the lowest capital outlay. What follows completion is largely irrelevant.
Also many offices are built speculatively, meaning they are less energy efficient than if they were designed with a specific end use in mind. Location can be a problem, too, as the built-up areas where companies want to buy often allow little scope to exploit features such as prevailing winds and sunlight.
Energy efficiency often comes low on the list of priorities for builders of houses, too. Here the main problem is one of duplication: a building designed to benefit from facing a certain way is of little use on an estate where homes are oriented in many directions. It is, however, far too simplistic to blame developers alone for this orgy of inefficiency. Companies reason, quite logically, that people will work better when cool and unflustered. If that entails air-conditioning and higher running expenses, so be it. But the drain from equipment can also be heavy, with the air-conditioning used to keep a computer’s temperature down typically costing as much to run as the machine itself. The energy that goes into cooling a subterranean City dealing floor packed with people and hardware is ‘astronomical’, says the BRE.
Despite all this, innovative systems of cooling are being developed and offices are being better tailored to their functions. A museum under construction in Bristol features a tank of eutectic salts, which absorb energy as they melt in the heat and release it as they re-solidify when it gets colder.
Traditional cooling methods pioneered in some of the world’s hotter countries could also provide solutions. Such as the onion model in which a building is divided into several layers, with the inner core providing cool in the summer and warmth in the winter.
There is, of course, always the siesta option – but that would require a pretty sharp change in public attitudes in frenetic societies such as Japan and the US, not to mention chilly old Britain. Why even vehicle air-conditioning is recording a phenomenal growth in Northern European countries where the climate hardly makes it essential. In Britain, the number of cars with it installed is expected to rise from 5 per cent in 1992 to 62 per cent in 2002. It is, says the Society of Motor Manufacturers and Traders, what people want.
Yet a Harris Research Centre poll of office workers could cast some doubt on this conviction – 89 per cent of them preferred buildings without conventional air-conditioning. If all else fails, this might just be the stumbling block that stops artificial cooling methods in their tracks. air-conditioning feels unnatural, and no amount of advertising or technical refinement is going to persuade people otherwise.
This point has already been made subconsciously by the Cannons members who complained about the gym’s atmosphere earlier this year. The main reason it seemed unsatisfactory was surely because it suffered by comparison with the crisp river air available outside.
Michael Peel is a Financial Times journalist.