Our air exchanger is bringing in cold air into the house - abour 12°C when its on exchagne and 16°C whne its on filter (average temp in hte house is 20-22°C) - even though there is suppose to be a heat recovery system. The unit is in the basment which is not heated and is usually at 12°. I've checked the unit and at the last service they said it was working fine. Is it that were losing too much heat in the unheated basement? What are the implicaiton of not running the unit in the winter? Obviously, this is not an issue during warmer months.