This Cool Air Conditioning System is Making its Way to Cities Worldwide

It’s a perfect summer day, 85 degrees and sunny. There is a light breeze and the birds are singing in their nests. Inside the house, you are perfectly cool and comfortable. After all, your air-conditioner cools your house to a pleasant 75 degrees. Did you ever wonder how an air conditioner works? How does it take 85-degree-air and cool it to 75 degrees? Well engineers in Toronto know, and they are actively finding ways to improve it.

How your air conditioner works
Live Science has the scoop. The typical air conditioning unit works thanks to chemicals called refrigerants. These substances are shot through your A/C pipes at freezing temperatures in liquid form. 

The hot air in your house interacts with the refrigerant and cools down to the perfect temperature. Meanwhile, the refrigerant, now heated to gas form, exits the house and enters a compressor and condenser unit that reverts it back to liquid form so it can circulate yet again. 

Luckily, modern air conditioners do their jobs well and keep our homes from getting too humid. Unluckily, the refrigerant is a terrible pollutant and can cause increased greenhouse gasses if leakage occurs. One A/C unit full of coolant can cause as much pollution as burning 1,100 gallons of gasoline according to Tech Crunch.

Lake Ontario to the rescue
Modern problems require modern solutions and the city of Toronto has found a uniquely innovative way to cool homes, while providing clean drinking water to residents. And it uses a fraction of the energy that traditional air conditioning units do.

According to The Washington Post, the deep lake water cooling (DWLC) system uses (as the name implies) deep lake water in place of refrigerant, compressors, chillers and condensers.

It turns out that the bottom of Lake Ontario, 280 feet under the surface, is cold. Really cold. The cold air sinks to the bottom of the lake, keeping it at a consistent four degrees Celsius (39.2 degrees Fahrenheit.) And that’s good news for the air-conditioning industry. 

The solution is very simple. Cleantechnica explains, freezing water is piped out of the bottom of Lake Ontario. It is used to super-chill city air conditioning pipes. Then, those systems, cooled by the lake water, circulate, spreading the chill as they go.

Buildings that are connected to the DLWC system, which includes prestigious places like the ScotiaBank Arena, City Hall and the Toronto General Hospital, act as conduit for the frigid solution that cools their air. The best part? After the water does its job cooling the city, it doesn’t simply get  evaporated away.

Instead, it continues on to its final destination- a water treatment plant, where it is purified and made potable and gets a new lease on life as part of the drinking water for ordinary Torontonians. According to Enwave, the company running Toronto’s DLWC, the system saves up to 220 million gallons of water annually!

DLWC’s global presence
With the push for greener cooling systems, DLWC systems exist in dozens of places worldwide, including Bahrain, Cornell University and Hong Kong. But Toronto’s system dwarfs them all. Enwave has grown from having only a handful of customers in 2004 when they set up shop to hundreds of major city buildings. This is good news for Enwave that needed to invest 170 million Canadian dollars to set up the infrastructure.

So, if you ever find yourself comfortably cool while cheering on the Raptors at the Toronto Scotiabank arena, you can thank the Great Lake.