[DanO2772]

Being a COB (cheap ol' bugger) and living in a superinsulated house, I abhore sending all that hot dryer air outside to heat the great outdoors. My house has a air-to-air heat exchanger which basically pulls in outside air, transfers the heat from the outgoing air (warm) to the incoming air (usually cold - Montana, more than a mile above sea level).

Does anyone know where I can find info about doing the same with my dryer output. Basically surround the outgoing dryer pipe (4") with a larger pipe (I'm thinking 8"). The 8" pipe would suck in house air at 72 degrees near where the 4" pipe leaves the building. That 72 degree air would flow by the 4" hot dryer output pipe and in the process transfer heat from outgoing air to the incoming "house" air. On the "dryer end" of the 8" pipe, that would be vented to the air supply of the dryer (usually supplied by the room air surrounding the dryer).

The result would be that theoretically the air leaving the house would be cooler due to the house air flowing by it. The air entering the dryer would be pre-heated, thus requiring less energy to heat it. ( Less heat wasted )

There would be a moisture condensation problem with the hot, moist air cooling down and releasing condensation.

Maybe I should actually provide the supply air from outside where the delta T (difference in temperature) would be greater and the heat transfer would be greater. In my sealed house, if air is going out in one location, it is being pulled in from somewhere else outside.

If there's any other whackos who know somewhere to look for this info, I'd appreciate the input.