Originally Posted by twinAK
Nice looking work. We're going to have one of these installed in our house when we get to that stage, probably another 2 years out. How did you figure out the unit sizing and ducting required? Since the air is not stale anymore, I bet you don't get sick as often. We had too much humidity in our old house and installed a bath fan switch on a programmed timer as a fix since retrofitting an HRV was very expensive. But I'm convinced the HRVs are the way to go from the start, at least in a cold climate.
As for the unit sizing there were different methods posted on the web, but the easiest was figuring for the number of occupants and then so much per room/kitchen/bathroom. The smaller unit wasnt that much less in price, the 1.0 model, and the 2.0 was too much air, so the 1.5 seemed to be just right for this setup.
As for duct sizing, the unit has 6" ports so your main trunks would be 6" for this unit, if you had multiple branches for your all your rooms, then you could likely use 5" for these. The instructions gave good information about selecting the proper duct size for the minimum CFM air movement.
As for being sick, we were doing very well all winter until last week our son got sick and we all got it, but I would have to say the fresh air really helps with indoor air quality, like when cooking the odor clears out of the house much faster. I have decided to not go ahead with a kitchen exhaust fan to the outdoors now because the HRV does so well. When you put your face near the fresh air register you can smell the freshness, its like being outside yet without the really cold part
This unit can be retrofitted with an ERV core, I am thinking of doing this for the summer just for the basement so I can refresh the basement air yet not bring in the outdoor humidity. I will have to see how much the ERV core will cost.