Four options for air conditioning

Canada may be famous for cold temperatures, but most of us also experience hot summers, too. If you’ll be installing or upgrading an air conditioning system this season, there are four main options to consider. The one you choose depends on the investment you’re willing to make and how much cooling action you need where you live.

WINDOW AC

This is the simplest choice that’s also the most economical to operate and the quickest to get up and running. Window air conditioners deliver the least cooling power of all the choices here, the most in-room noise and they don’t look great sticking out of a window. That said, window AC definitely has a place, especially in cooler parts of Canada. We use a window AC at our house, and even then some summers aren’t hot enough to bother installing it. When I do install it for the season, one 12,000 btu/hr unit upstairs does a good job cooling two floors totalling 2,000 square feet of floor space. We run it at night, when electricity is cheap, then close blinds during the day and coast on the cooled air until evening comes again. Used this way, it costs just a few dollars a day to make our home cool.

DUCTLESS MINI-SPLIT

If you’ve seen a louvred rectangular box mounted high up on a wall in a home or restaurant, you’ve probably seen the indoor half of a ductless mini-split. The other part of the system – the compressor – sits outside. When ductless mini-splits first appeared in a big way about 25 years ago, they were for cooling only. These days the best mini-splits deliver cooling as well as a modest amount of heat indoors when it’s cold outside. You wouldn’t want to rely on a ductless mini-split to get you through a Canadian winter, but they do provide heat economically during the shoulder seasons – two or three times more economically than baseboard heaters. As the name suggests, ductless mini-splits need no forced air ducts to operate.

CENTRAL AC

This may be the most common type of cooling system in Canada because it was installed for so many years and continues to be installed. Central air uses the same sheet metal ducting that a furnace would use for heating in the winter, except that cool air flows. Central AC delivers wholehouse cooling action only, with no heating capabilities. It’s also the most expensive to operate because it cools the entire house and duct system, air leaks and all. Central air is generally the least expensive whole-house system you can install.

With a name like this you wouldn’t think of cooling action, but today’s best heat pumps operate both ways, delivering whole-house cooling as well as whole-house heating. Heat pumps come in two main types, ground/water source and air source. When it’s hot indoors, a heat pump moves that excess heat outside, making your home cooler. When your house needs heat in winter, heat pumps harvest heat from the air, soil or a nearby body of water, then concentrates this heat energy before delivering it indoors. Since heat pumps move heat energy around (as opposed to generating it from scratch like an electric baseboard heater) they deliver much more heating action for a given unit of electricity. For a given quantity of heat delivered by a baseboard resistance heater, a heat pump will deliver two to three times more heat for the same electricity consumption. It’s a great deal, but heat pumps are one of the most expensive systems to install.

We Canadians might not live in what’s considered a hot country, but still, a little AC action goes a long way to boosting comfort when humidity rises and the cicadas start to sing.

We Canadians might not live in what’s considered a hot country, but still, a little AC action goes a long way to boosting comfort when humidity rises and the cicadas start to sing. HEAT PUMP

Today’s best mini-split units like this one can deliver air conditioning during hot weather, and modest amounts of heat during winter.

This air source heat pump moves excess heat out of your house during hot weather. During cold weather it works in reverse, harvesting heat from the outdoors and concentrating it in your home.

This ground source heat pump functions as air conditioning in summer and a heat source in winter. Installations like this deliver roughly three times more heat from a given quantity of electricity than resistance heaters.