Sales of air-conditioning units boomed during the July heatwave that saw many areas of northern Europe enduring record-breaking temperatures. Such units keep people cool, but the carbon dioxide they churn out could wreck attempts to meet Kyoto protocol targets, says a report by the London-based Association for the Conservation of Energy (ACE).

The UK government is hoping that energy-efficient housing will cut the country’s CO 2 emissions in 2020 by 5.5 million tonnes. The scheme is one of the central planks in the country’s strategy for meeting Kyoto protocol targets, and is particularly important because residential energy use has been growing at 1 per cent a year – about three times the rate of the commercial sector. But the ACE report, released this week, predicts that by 2020 emissions of CO 2 from domestic air conditioners could hit 4.9 million tonnes per year.

The study assumes that as global warming sends temperatures soaring, Europeans will come to expect the same level of comfort as people in the US, where two-thirds of homes have air conditioning, compared with 5 per cent in Europe. In the UK, ACE predicts this will rise to 16 per cent of homes by 2020, concentrated in southern England, where a whopping 84 per cent of homes are expected to have air conditioning, says Anson Wu, one of the study’s authors. Neighbouring countries such as France, Germany and the Netherlands are likely to see even faster growth in air conditioning because the continental climate has greater extremes of temperature.

The best way for healthy people to cope with hot weather is to use blinds to keep out the sun during the day and to open windows at night, says Wu. If you must have air-conditioning, avoid mobile units with exhaust hoses that have to be put out of the window. “That just lets in the hot air.”


Terry Dix, a ventilation specialist with the international civil-engineering consultancy Arup, says we should avoid domestic air conditioning completely. “That should be readily achievable.”

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