Cottage Q&A
QUESTIONWe visit our cottage all winter. It is heated by oil and we turn the thermostat down to 4°C when we leave. I have been told that if I go to the cottage every weekend, I shouldn't turn the heat down so far because more energy is used to heat the place up than to keep it warm while I'm gone. Is that true?
ANSWER
Without knowing the construction details of your cottage we can't give you an exact setback temperature. Finding an appropriate number depends on both the outside temperature and the building's construction: the quality of insulation; the amount of air leakage, in and out; as well as the efficiency of mechanical and heating systems.
However, Ernie McFarland, a professor of physics at the University of Guelph, says "it always saves energy and money to turn the temperature down, whether it is for five minutes or five days." A furnace is intended to replace the heat as it escapes from the building. The slower the heat escapes, the less your furnace will have to kick into action. The rate of heat escape depends on the temperature difference between the outside and the inside. The closer you make the inside temperature to the outside temperature, the slower the heat will escape. Even if it takes several hours to reheat the cottage once you return on Friday, you'll still be using less energy than if the furnace had to cycle on and off to maintain a higher temperature during the week.
So, when you consider just how low to go during the week, use common sense: Think about how cold it is outside and how well insulated your cottage is. A professional energy assessment will also help. For more information, go to the Office of Energy Efficiency website at www.oee.nrcan.gc.ca or visit the Canada Mortgage and Housing Corporation at www.cmhc.ca.
A final word from Pierre Gallant, technical advisor for Natural Resources Canada's Office of Energy Efficiency, who warns that setting your thermostat as low as 4°C will make your pipes vulnerable to freezing if there's a power outage or cold snap.
* Published in the November/December 2006 issue of Cottage Life
