HRV systems in Calgary?

[daplatapus]

I've installed many HRV's in my work. And while they do help cut down on humidity, that function really is only a byproduct of it's main function and will not always be effective at removing humidity. Basically a HRV draws air from outside, passes that air through a heat exchanger, then distributes that now warmer air to the home. At the same time, another fan draws air from your home, passes that air through the other side of the heat exchanger, and exhausts it outside. So what you are really accomplishing is preheating cold air from outside with your exhaust air from inside.
Warm moist air from inside your house condensates in the heat exchanger that is made cool from the incoming air from outside and in effect de-humidifies your inside air. But you're exhausting that air anyway so in effect an exhaust fan will do the same thing, but the HRV re-captures the heat you spent money on to produce by your heating system.
The less temperature difference between your inside and outside temp, the less de-humidifying you'll see.

I hope that makes sense. If not, ask away and I can try to answer you.
FYI here's a quick pic of an HRV to show the heat exchanger. The air from inside your home and outsde never actually mix, they just pass by one another in the heat exchanger.
http://www.popularmechanics.com/cm/p...ihwab-1-md.jpg