Designers, scientists look to reduce air conditioning’s environmental impact

July 15: Canada is often thought of as a winter country, but our summers are sometimes brutally hot. The blast of air conditioning is sometimes the only thing that can bring relief, aside from jumping in a body of cold water.

But many Canadians are concerned about the effects of climate change brought on by the energy consumed by air conditioning systems.

This is spurring some innovation, and some do-it-yourself experiments. But a fully environmentally friendly air conditioner may still be a long way off.

How bad are they, really?

For many, the idea of living without air conditioning during a hot summer is a sweaty, uncomfortable nightmare. And when it’s hot out, there’s only so much a person can do.

“If you’re cold, you can put more clothes on and the more things you put around your body, the more you’ll insulate your body,” said Alan Hedge, a professor of design and environmental Analysis at Cornell University in Ithaca, N.Y. “But if you’re hot — once you’re completely naked, you can’t get rid of anything else. That’s as far as you can go.”

Walk down the street in any major Canadian city and you’ll see stand-alone air conditioner units perched outside windows. And many houses and apartments have central systems that run cool air through the entire building.

But these systems are generally not energy-efficient, and they also make use of chemical refrigerants that are harmful to the environment.

“There’s not a system I know of commonly available that would have no refrigerant in it at all,” said Tyler Hermanson, a Leadership in Energy and Environmental Design designated home designer in Calgary. LEED is a designation given to energy efficient and sustainable buildings.

He said the cheaper the system, the more likely it is that it uses lower-grade, higher-risk refrigerants (although ozone-depleting refrigerants were banned in the ’80s).

Stand-alone window systems are the hardest on the environment, said Hermanson.

“Those ones can be really bad both in terms of energy consumption and also in terms of the refrigerants they use,” he said. “They’re going to have all sorts of nasty stuff in them.”

Chemical companies are constantly designing refrigerants to lessen their environmental harm.

“They’re hoping they’re going to find this magic chemical combination that will work, but at the present time, the refrigerants we’re using are decent, but they’re not the best they could be,” said Robert Carder, a heating, refrigeration and air conditioning professor at Conestoga College in Kitchener, Ont.

Build it better

Hermanson said that if a house is well-built, it doesn’t need air conditioning. He said the same things that keep a house warm in the winter will keep it cool in the summer.

“If you make smart choices in terms of your wall insulation and your air-tightness and your window selections, design for proper shading in the summer and things like that, you can drive down the air conditioning loads to the point where it doesn’t make sense to have air conditioning at all.”

Hedge said traditional Roman villas made use of courtyards in the middle, often with some kind of water feature at the centre.

“That’s a mechanism for keeping the house cool in the summer,” he said.

Hedge said buildings made in hot climates are often built to incorporate a lot of air movement. They’re also often painted light colours, like many houses in the Greek islands.

But for the rest of us who don’t live in a Roman villa, on a Greek island, or in a LEED-designated home, what are we do to?

What about solar?

Scientists have been experimenting with solar power for years — it doesn’t eliminate the use of refrigerants, but it does use an energy source that is environmentally friendly.

Marie Nghiem is part of a team of engineers that created a solar-powered heating and cooling system for a building in Mandelieu, in the south of France. The goal of the project was to reduce emissions, as well as the energy bill, for buildings where it’s installed.

The system uses large, curved glass panels to capture solar energy. That energy is then run through their specially designed system and used for cooling or heating.

Nghiem said it has the ability to reduce a building’s energy bill by 80 per cent. The project is promising, but currently, it has a few downsides. It only works when in full sun — it switches to a biomass system when it’s cloudy or raining.

Another downside is the expense — it costs from 100,000 to 500,000 euros to install, making it viable for industrial buildings only.

Until the cost can come down, it’s unlikely you’ll see solar-powered air conditioning units in every window.

DIY options

Some people have been looking at do-it-yourself options when a simple fan won’t cut it. Videos have been cropping up online promising a cheap, simple solution to your air conditioning needs.

They generally work by retrofitting a cooler with a fan, vents, and some ice. Megan Keenan and her boyfriend, who live in Toronto, were inspired to try it. They invested about $50 and half an hour to assemble the device. But it didn’t turn out the way they hoped.

“It just wasn’t cooling the bedroom — it was disappointing,” she said. “Unless you’re right next to it, it doesn’t make a difference.” Hopes dashed, Keenan said they ended up using a regular fan. And they had to throw out the now useless cooler, which was riddled with holes from their experiment.

For those of us hoping to beat the heat while not hurting the environment, Carder and Hermanson suggest an air conditioner that also takes the humidity out of the air. That will help a house feel cooler when the humidex is high, without having to decrease the temperature as drastically.

You can also use a fan, or if all else fails, dunk yourself in cold water. cbc.ca