I was looking into a heat exchange unit for the forced air heating system. Natural i would like more fresh air. I don't have a very big house or big heating requirements. Seems the air is still recycled with heating recycling unit but the fresh is added to the return vent. Wouldn't it just be easier to cut a 1-1/2" hole at the intake return to the furnace and run a pcv pipe out through the wall so it can get bit of fresh air add? I could just block it up in the warmer times and use it when it gets really cold. Time you pay for the HRV and the fan is suppose to run might as well just let a little fresh air into the intake? The unit is $1000 plus the power to run the fan.