Keep cool this summer without using an air conditioner

Image of BC Hydro rep, Jeff White
BC Hydro community rep Jeff White recommends avoiding air conditioning in favour of strategic use of window coverings and windows. And for those windows on the hot side of your home, consider applying a sun-blocking film.

By being strategic with cooling, you can stay comfortable, keep bills low

Jeff White

As the summer months approach and temperatures rise, we'll be slapping on the sunblock and enjoying the beautiful countryside, lakes, and rivers in B.C. But when we come home from a long day in the sun, nothing feels better than stepping into a cool house.

How do you ensure your home is cool on the hottest days of the year? And how can you do it without turning to an air conditioner and increasing your electricity bill?

If you're using a heat pump, save it for the hottest days

If you've installed a heat pump in your home, you might use the air conditioning function provided by the pump to cool your home in the summer. However, it's important to note that regularly using your heat pump for cooling could increase your electricity costs significantly. And if you haven't used the air conditioning function in past years, you'll see a big year-over-year increase.

If you're thinking of buying a heat pump, keep in mind that an air source heat pump with a SEER rating of 20 will typically reduce cooling costs by 50%. And opting for a ductless split air source heat pump with a high SEER rating can save over 50% in cooling and heating over low-SEER heat pumps.

It may be more efficient to change the way you're using your blinds, windows and fans, and save the heat pump's air conditioning feature for only the hottest days of the year. Learn more about how to optimize your heat pump.

If your house is really hot, consider cooling just one room

Sometimes, it's all about getting a good night's sleep. One of BC Hydro's engineers installed an ENERGY STAR®-rated window air conditioner unit in the bedroom, and reports that it works wonders without adding up to huge additional costs on his bill. Even if that unit ran at night for three months over a really hot summer, it would add up to about $40 in additional electricity costs over that time.

Image of boy drinking lemonde
We all love the summer, except when it gets so hot that we can't be comfortable or get a good night's sleep in our homes.

Blinds and curtains aren't just for privacy

One of the most effective changes you can make to prevent heat from getting into your house is to install blinds or curtains, and to use them strategically. This can reduce your solar gain – the amount of heat generated by sunlight spilling through your windows – by 40 to 50%. Make it a priority to install blinds and curtains in the areas of your house with the most sunlight during the day – usually your south and west facing windows.

You should also consider whether you want windows that don't open, which tend to be more efficient in keeping out heat in the summer, or ones you can open. The ability to open windows provides you flexibility to open them in summer mornings and evenings when sunlight isn't an issue and the air flow can help cool your home.

The rule of thumb? During the day, when the inside temperature is cooler than outside, keep your windows closed. In the evening when the outside temperature is cooler than inside, open downstairs windows and place fans near them to create ventilation paths through your home. That flow will ideally pull cooler air through the home and push hot air out through other open windows.

An indoor-outdoor thermometer is a great tool to help determine when the outside temperature drops below the inside temperature.

Really want that view? Consider sun-blocking films for windows

Sometimes, you just don't want to block that view through the windows, or maybe you just need to keep an eye on the kids in the yard. To help cut the amount of sunlight warming your home, consider installing low emissivity films [PDF, 296 KB] (also known as "low-e films") on your existing windows.

Low-e films block out most of the heat from coming into your house while still allowing most of the light inside. From the inside, it's hard to tell that these coatings have even been installed, although they may give the window a slight mirroring effect.

Low-e films are also useful in the winter months to insulate and help keep the warmth in. Once installed, it will be important to take extra care when washing your windows to help the film last.

Not all windows are created equal

Do your windows need an upgrade? Consider installing new ENERGY STAR windows, and check to see that the windows you buy certified for your climate zone.

Many windows, doors, and skylights are certified for more than one zone. You may save even more on energy costs by buying a product certified for a colder zone than where you live. However, if you buy a window rated for a zone that's warmer than the zone you live in, you may discover that the window does not insulate as well as you expect.

Learn more about ENERGY STAR windows and window efficiency from Natural Resources Canada.

Finally, here are two other ideas to help keep your home cooler in the summer:

  • If you have ceiling fans in your home, switch them to rotate in a counter clockwise direction. This will create an artificial "wind chill" effect that helps you feel comfortable when temperatures rise.
  • If you're making changes to your outdoor space, install shades, awnings, and plant shade trees along sun-facing windows to help prevent overheating from the sunlight.
  • An indoor-outdoor thermometer is a great tool to help determine when the outside temperature drops below the inside temperature. When this occurs opening windows and doors will help to cool your home as opposed to heating it up.

Jeff White is a member of BC Hydro's community team.