Half of residents hit by air-con exhaust

PUBLISHED : Monday, 27 September, 2010, 12:00am
UPDATED : Monday, 27 September, 2010, 12:00am

Poorly designed buildings expose half the city's residents to hot air blown from neighbours' air conditioners, a survey by an environmental group has found.

Green Sense polled 1,262 residents this month and found 53 per cent were forced to switch on their air conditioners because of hot exhaust from neighbours' air conditioners making their flats uncomfortable.

It also studied 13 public, private and Home Ownership Scheme estates and found the air-conditioner positions of 11 were poorly designed.

Green Sense chairman Roy Tam Hoi-pong said the temperature of air conditioners' exhaust could be as high as 40 degrees Celsius, and would increase the temperature of the surroundings by two or three degrees.

'We did not expect the number of residents affected was that high,' he said. 'This shows that the floor-plan design of many buildings is very wrong.'

He said the situation on Lung Mun Oasis, Tuen Mun, was the most extreme, with air conditioners just 10 to 30 centimetres away from the living rooms of adjacent flats. He said its floor plan was typical of other Home Ownership Scheme estates, with 10 flats on each floor. He estimated at least 20 other HOS estates had similar air conditioner positioning.

Public estates were no better. Air conditioners on Yuen Chau Estate, Cheung Sha Wan, were on average one metre from adjacent flats.

'The government used one floor plan in designing all the public housing. So if the plan was problematic, all the estates were affected,' Tam said.

The same problem existed on some private estates as well. Air conditioners on La Grove, Yuen Long, developed by Sun Hung Kai Properties, did not affect adjacent flats, but exhaust was directed into a gap two to three metres wide between buildings. Tam said exhaust fumes confined in this small space would accumulate and breed bacteria easily.

Two buildings that earned a merit from Green Sense are York Place in Wan Chai, and Island Crest in Sai Ying Pun. Both private buildings have good ventilation for exhaust from air conditioners.

The green group urged the Buildings Department to update guidelines to require adjacent buildings to be 15 metres apart. It suggested developers conduct heat exhaust emission analysis when they design buildings. Tam said this could help ease the heat island effect.

Tam also asked residents not to switch on air conditioners when the temperature was below 28 degrees Celsius and to use electric fans instead of air conditioners, which use 10 times less energy.

The group has organised a 'No air-con night' on Wednesday. So far, 100 schools, 45 enterprises and 50,000 families, including those of Environment Secretary Edward Yau Tang-wah and Observatory director Lee Boon-ying, have pledged not to use air cons from 7pm to 7am.

Big appetite

An air conditioner uses this many times more power than an electric fan: 10