During an intense heat wave, the temptation is great to turn on your air conditioner to enjoy a bit of coolness, or to get one. But at what cost to the environment?
“If we tightened the screws on air conditioners, how much CO2 would not go into the clouds? », asks Jacques Mercure.
Every summer, in Quebec, the sale of air conditioners explodes. Nearly two-thirds of Quebec households have one today, compared to 54% in 2013, according to Statistics Canada.
But despite the saving coolness they provide, air conditioners are not unanimously accepted. “It’s an unfortunate debate,” admits Dr. Stéphane Perron, of the National Institute of Public Health of Quebec (INSPQ).
In terms of health, numerous studies carried out around the world have shown that air conditioners save lives every year. They reduce the risk of mortality and health problems linked to heat, confirms a report published in 2022 by the INSPQ.
In addition, air conditioning helps reduce exposure to contaminants (chemical compounds, spores, mold, pollen) coming from the outside, provided that you keep the windows closed during use, ventilate in parallel and maintain the air well. he device – especially its filter.
Note, however, that an air conditioner set at too low a temperature can have the opposite effect. Torticollis, headache, allergic symptoms, dryness of the mucous membranes, thermal shock, cardiovascular problems: when the device is set to less than 20°C, the health risks multiply.
Air conditioners also raise several environmental issues.
According to data from Natural Resources Canada, in about 20 years, energy consumption used to cool homes has almost doubled – because although new appliances are more efficient, more and more households are using them. provide.
According to the Hydro-Québec calculator, central air conditioning from the 1990s with a capacity of two tons consumes more than 1,500 kWh during the summer. This corresponds to the added consumption of an electric stove, a dishwasher and a dryer over one year. But newer air conditioning can consume around half as much.
Air conditioners pose another challenge: their recycling. They contain a refrigerating gas – just like refrigerators – which circulates in a closed circuit and which cools the air. The most dangerous gases, chlorofluorocarbons (CFCs), were banned in 1985 thanks to the Montreal Protocol. They have since been replaced by others, whose environmental impact is less, but not negligible.
The problem is that when an air conditioner reaches the end of its life, we tend to leave it on the sidewalk. It can then end up in landfills or be collected by metal dealers who do not necessarily know how to treat these gases. These therefore often end up escaping into the atmosphere.
“If you leave your air conditioner in the street, all the efforts you make for the environment on a daily basis can be canceled out by this gesture,” summarizes Jules Foisy Lapointe, general director of GoRecycle.
Mr. Foisy recommends taking your old air conditioner to a GoRecycle collection point, the only organization recognized by Recyc-Québec to ensure the recycling of this type of device, so that these gases are treated and disposed of correctly. Currently, the organization estimates that it manages to recover and recycle less than 2 out of 10 air conditioners thrown away in Quebec.
Last issue, but not least. Perhaps you have ever felt a breeze of warm air in an alley where air conditioners line the exterior facade of buildings.
In an article published in 2020 in the journal Environmental Research Letters, French researchers showed that, during a heatwave that hit France in 2003, air conditioning helped warm the streets of Paris and its suburbs. Because of this hot air released outside, some neighborhoods saw the mercury rise up to 3.6°C higher than if there had been no air conditioners.
For Florent Barbecot, professor in the department of Earth and atmospheric sciences at the University of Quebec in Montreal, this is the heart of the problem.
He emphasizes that this also raises a question of social justice, since it is in disadvantaged neighborhoods that people own less, live in less well-insulated buildings and therefore suffer the most from the heat.
Several alternative solutions were proposed by the experts interviewed by La Presse, such as improving the insulation of buildings or creating more green spaces.
“The leaves of trees work like mini air conditioners,” says Florent Barbecot. Except that a tree has no negative environmental impact, it’s free and it brings well-being. »
But in the short term, the most effective solution for coping with heat waves remains to use an air conditioner moderately – Dr. Stéphane Perron suggests choosing a temperature between 22 and 26°C. Advice that is not limited to individuals: around the world, many companies and institutions are committed to having a lighter hand on air conditioning.
“As climate change progresses, unfortunately, air conditioners are going to be more and more essential. The goal is to try to use them intelligently,” he says.