Save energy - use air conditioners properly

PUBLISHED : Monday, 05 June, 2006, 12:00am
UPDATED : Monday, 05 June, 2006, 12:00am

Many people switch on their air conditioners at night, especially during summer. But a survey has found that 25 per cent of respondents kept their bedroom temperature so low that they wake up shivering.

The study was conducted by Deng Shiming, associate professor of building services engineering at Hong Kong Polytechnic University, between September 2002 and May 2003.

Questionnaires on sleeping habits were given to 554 people. The findings of the survey will be published in the academic journal Energy and Buildings.

Dr Deng and environmental organisation Friends of the Earth (FoE) Hong Kong announced

the survey results at a press conference last month.

The study found that 80 per cent of respondents kept their bedroom temperature at 24 degrees Celsius or below and 20 per cent kept it at under 20 degrees Celsius, well below the 25.5 degrees Celsius recommended by green groups.

Fifty-two per cent of the respondents said the cooler temperatures did not significantly improve the

quality of their sleep.

A quarter of the respondents said they sometimes woke up shivering as the bedroom was too cold.

Dr Deng said this showed that people set their room temperatures too low, which was a waste of energy.

He also pointed out that half of the respondents covered themselves with thick blankets while the air conditioner was on.

'Some people even wear long-sleeved shirts and pants to adapt to the cold bedroom. That's ridiculous! It's a waste of the Earth's valuable resources,' said Dr Deng.

'There is an urgent need for educational campaigns to help people develop the right attitude towards using air conditioners. The purpose of having air conditioners is to make us comfortable, not to make us shiver with cold.'

FoE (HK) suggests that people keep the room temperature at around 25 degrees Celsius and wear shorts and T-shirts instead of pyjamas.

People should also adjust their air conditioners to avoid a cold draught blowing directly at them, the green group said.

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