Keeping your house cool without heating up the planet

As the days get warmer you might start dreaming of air conditioning in your home. However, there are many other ways keep your house more comfortable during our hot summer days that are easier on your wallet and the environment.

  • Jun. 7, 2011 8:00 p.m.

Thermalstat! by Chantal Keerak

As the days get warmer you might start dreaming of air conditioning in your home. However, there are many other ways keep your house more comfortable during our hot summer days that are easier on your wallet and the environment.

Humidity and air movement play a big part in determining how comfortable we feel at a particular air temperature. Humidity makes the room air feel warmer so reducing activities that generate humidity and using ventilation fans during showers and cooking will help keep the home more comfortable.

The wind-chill effect created by fans can make a room feel 3 or 4 ºC cooler than it is. Ceiling fans in the bedrooms work wonders and portable fans can be quite effective as well. A typical ceiling fan will use about 10 – 100 Watts which is a very small fraction of what an air conditioner would use. If you are looking at purchasing a ceiling fan look for one that is ENERGYSTAR rated, has the ability to turn in both directions, and the lights can be turned off without turning the fan off. A ceiling fan can also be run on low in the winter months to help disperse the warm air that rises towards the ceiling. We often get asked what direction the fan should be turning in summer and what direction it should be turning in winter. The best way to tell is to stand under the fan and try it on high in both directions. The direction that you feel the most breeze is the one you should use during the summer months.

Running the furnace fan will help circulate the cooler air in the basement throughout the rest of the house.  If you can’t turn on your furnace fan from your thermostat, a switch can be installed on most furnaces to allow you do to this. Placing a fan in front of some of the windows and running bathroom exhaust fans at night will help draw the cooler air in and bring the temperature of the home down.

Attics can reach temperatures over 60ºC on hot summer days. If there isn’t much insulation between the ceiling and attic a lot of this heat is going to be transferred into the house.  Increasing attic insulation can make a big difference in the comfort level of a home and will also cut your heating costs in the winter. During my first July in our house we added R40 insulation to the poorly insulated attic and the temperature inside the house dropped by 3 – 4 ºC on hot days. Proper attic ventilation is also important in keeping your house cool and extending the life of your roof. Without it your attic won’t cool off as much as the sun goes down and will continue to heat your house throughout the night.

Windows on the south and west sides of a home can let in a lot of heat. Thicker shades and curtains on the south and west facing windows can help reduce this. Many fabric stores carry a lining that can be attached to most curtains or drapes which helps to keep the heat out. Other options for window shading include tinted and reflective films (speak to your window manufacturer to ensure it doesn’t affect your warranty), awnings and exterior window shades. One thing that I do which is very effective (but may get a few raised eyebrows from the neighbours) is to put a piece of reflective insulation, which looks like foil faced bubble wrap, in my south facing bedroom windows. It doesn’t look very pretty but it works wonders at keeping the temperature lower in those rooms.

When landscaping consider strategically placing deciduous trees and shrubs in locations that provide some shade to the west and south sides of your home. Also try to minimize the use of unshaded rock, asphalt or cement beside your home on the west or south sides as it increases the temperature in these areas and radiates heat to your home even after the sun goes down.

If you still can’t bear the heat in your home you may want to consider a heat pump. This will give you very efficient heating in the winter and also the option of cooling in the summer. If you are looking for a heat pump, air conditioner or fan look for ones that are ENERGYSTAR rated as these are the ones that have been proven to be more energy efficient.

There are grants available through LiveSmart BC for heat pumps, insulation, ventilation fans, upgrading air conditioners and other energy saving retrofits.  For more information on these grants visit

This is the final editorial in a series of eight. I’ve enjoyed writing these columns for the Revelstoke Times Review and hope that the readers have enjoyed them as well.


Chantal Keerak is a professional mechanical engineer. Her Revelstoke based company, VerdaTech Energy Management and Consulting BC, provides heating and ventilation system design and energy efficiency assessments for residential and commercial buildings throughout BC. She can be reached at 250 814-8719.