Just poking my head in here too. This cross heat recovery unit has a major drawback. It sends moist air out, and dry air in. With a rotating wheel you will condense the moisture from the outgoing air, and evaporate it to the ingoing air, so you keep a decent humidity level indoors. Also, this helps against the unit freezing up. If only the outgoing air is dehumidified, there will be a build up of water, which might freeze if the outdoor temperature is cold enough. We regularly have -20 here, so even the wheel based models have some issues. My unit is made by ener(.no), and they have two large aluminium fins and a 3 way air walve that directs incoming and outgoing air back and forth between them. To my mind this should work better when it is really cold, as the hot and cold side will alternate. Also, the unit should be somthing like 93% efficient when running in low mode.
-Ko_deZ-
|