two stage furnace thermostatThere are several factors to consider when making the decision about whether or not to buy a two-stage furnace, including the average temperature for your part of Ontario and, obviously, your budget.

Families living Woodbridge probably don’t need the same kind of furnace output as families in Thunder Bay, for example.

What we can say for certain right now is two-stage furnaces are far superior to their single-stage counterparts, and slightly less efficient than modulating furnaces. What we hope you can say by the end of this blog is whether or not a two-stage furnace is right for your family.

What do you mean stages?

Older furnaces are either blasting warm air or not. Burning fuel to produce heat or waiting to burn fuel to produce heat.

Two-stage furnaces operate at different increments, for example:

  • 100{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} when the temperature outside drops below -25.
  • 60{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} on most winter days when the temperature hovers around -15 or -20.

Your two-stage furnace may also start operating at 100{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2}, but drop to 60{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} to maintain the temperature.

The lower setting is important because it reduces the cold swings in your house and consumes less fuel in doing so. The furnace doesn’t blast out a lot of hot air, let the house cool, blast hot air, etc… It gets the house to the temperature you want and maintains that temperature through smaller, quieter, less noticeable burns.

How does the furnace know when to use a smaller flame?

two stage furnace pilot lightThe position of your fuel control valve is based on how often the thermostat is kicking your furnace on and off, in addition to the difference between the temperature set on the thermostat and the current measured temperature of the house.

The computer in the thermostat communicates to the furnace what is required, based on some nifty programming, and the furnace responds with the appropriate fuel burn.

How does that actually save energy?

Think about it like your car.

If you want to go really fast, like 100{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} fast, you put your foot to the floor and burn through fuel like crazy. You’ll go fast, but you will have to stop for gas sooner than you would if you only held the pedal down 60{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} of the way.

If your furnace can burn fuel at a rate of 60{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} and maintain the temperature in your house, you’re saving money. A single-stage furnace will burn much more fuel to achieve the same result.

The other bonus!

two stage furnace air filterA two-stage furnace filters your air better. It runs more often, circulates air through the filter more often and removes more harmful air pollutants that build up inside through the winter.

Stagnant air has the opportunity to collect and concentrate pollutants, while moving air has the opposite effect.

When you learn most indoor air is more dangerous to your family’s health than the air outside, you start to appreciate the value of good air movement and filtration from your furnace.

So is a two-stage furnace right for your family? It will:

  • Save on your energy expenses.
  • Heat your home more completely, eliminating cold spots and,
  • Filter your air better.

It will do all of this for a lower price than a modulating furnace.

If price is a consideration, two-stage is a great balance between cost and function. If you want the best of the best, talk to us about a modulating furnace.


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