Cool Cooling Tips

By Alex Brooks

The Bureau of Climate Alarm has a warning: anyone using an air-conditioner this summer will feel desperately guilty for creating carbon footprints bigger than a Yowie.

Somehow, blessed AirCon has morphed into an environmental enemy for its reliance on coal-fired electricity. But is all the hype true?

Sustainability experts like Kinesis’s Bruce Taper says houses and apartments without “passive cooling” features like external shading, cross-ventilation and insulation may have no choice but to rely on air-conditioning to remain habitable on hot days.

“If you have to use an air-conditioner, it’s about running it responsibly,” he says. “Don’t install air-conditioners larger than you need and don’t leave your door open to the balcony while you have it running. It’s best to zone the rooms and control the cooling.”

“If you want to be comfortable without using an air-conditioner, then the fundamental issue is to keep your home cooler than the outdoor temperature – don’t let it heat up during the day,” says RMIT’s associate professor Alan Pears.

He says simple things like sealing drafts under doors, shading windows (external blinds are more effective than internal) and insulating walls are effective tools in the fight to stay cool.

“One square metre of window facing the sun directly is like hanging a single bar radiator from the wall and switching it on at the hottest time of year,” he says. “It’s best to shade north, east and west-facing windows on hot days.”

Pears suggests home owners experiment to find out exactly which windows, doors or uninsulated walls are most responsible for heating up their house. “On a hot sunny day, hang a white sheet in front of a window that you suspect heats up the house – the sheet will block 80 to 90 per cent of the heat. If the house is still hot, then you need to keep looking to find the culprit.”

Energy Australia efficiency expert Paul Myors says ceiling fans are cheaper than running an air-conditioner. “A ceiling fan costs the same to run as a light bulb,” he says. The bonus of creating fast-moving air is that feels up to three degrees cooler.

“Of course, people can just refuse to use air-conditioners – that’s the best environmental solution, but hardly realistic on really hot days,” he says.