Fractured said:I think the question pertains to heat transfer via convection blower. Do you get more heat in the room with the fan on high vs out the exhaust with it on a lower speed. Think of the tubes as a giant heat sink, the more air that moves through them the more heat would be absorbed by them to try to balance the ambient temperature in them. I run mine on the higher speeds if I have the fire to support it. I may be wrong, I have before.