Cooling Britannia?

That's according the latest climate change predictions from the DTI (UKCIP02 for short). And as a result of these changes UK shops, offices, and homes will get hotter in summer, and the demand for them to be cooled will grow. That means the amount of energy required will grow, by as much as four times over the next 20 years. So says DEFRA's Market Transformation Programme. Even if DEFRA's figures aren't spot on, we're looking at a serious increase in energy use for cooling and air conditioning. Does it matter?

The DTI's climate change report suggests that "the climate of the second half of the 21st century will be increasingly influenced by the volume of greenhouse gases emitted over the next few decades". In other words, whether the energy demand from air conditioning is going to rise threefold or fourfold, it matters.

We could follow the Swiss approach and ban air conditioning unless a specific case can be made for a particular building. We could suggest to the Treasury that air conditioning would be a good target for another stealth tax, with an excellent predicted long-term rising yield. Somehow, neither of these seems to be a likely candidate for success. So what could work?

There is no single simple solution, but there is a variety of options to choose from. Increased awareness of passive design options would be a start. Can the building be orientated and massed to minimise solar gain and maximise shading?

A check on the design margins might be prudent. Are the predicted maximum cooling loads accurate? Or do they include an allowance "for good measure"? Margins are even more notorious sources of error than climate change predictions, so it is worth asking awkward questions early.

It may be that the site is on a busy city road, with noise and pollution around so that natural ventilation is not acceptable. Or the processes going on in the building are generating cooling loads that demand mechanical cooling systems. All is not lost. Is the system specified efficient? Can it be controlled so that it provides the cooling required, when required? Are the components chosen with any thought to their energy efficiency? The Market Transformation Programme website provides access to a growing database of information about the efficiency of such equipment, and CIBSE Guide B2 provides guidance on the design of mechanical cooling systems.

As with many other design questions, asking them early can be cheap. The later they are asked, the more costly they become. But the more they are asked, and become common practice for design, the slower the demand curve will rise. And the more the industry – whether designers, installers or clients – challenges equipment suppliers to provide low energy solutions to cooling problems, the more likely that innovative solutions will be offered.

This may seem idealistic. It need not be. Economic cars doing 40 mpg with low exhaust emissions, power steering, anti-lock brakes, and many luxury items are taken for granted today. Yet a brief recollection of what we drove a mere 10 years ago shows what can be done with a combination of government targets and consumer demand on the one hand, and industry innovation on the other.

The air conditioning industry could follow a similar course. There are incentives to reduce energy use, though not yet powerful; there are clients who want low running costs, though they are not yet the norm; there are manufacturers pushing the boundaries of performance for those willing to buy on performance and not cost. The signs are that the recent energy review may stimulate further measures to promote energy efficiency to add to this mix. There are already signs that government is looking at barriers to low carbon technologies in its consultation on the energy review, which is due to lead to a white paper on energy later this year. And the new EU directive on the energy performance of buildings will provide a further stimulus in that direction. A Swiss-style ban may seem unrealistic, but if the growing demand for energy for cooling is not abated by market forces, the case for intervention and forcible restraint will grow. Who knows, in the worst scenario it might even attract the attention of a not so stealthy tax. With good design and consistent innovation it should never be needed.