I had a new central A/C unit installed last spring. It is a Lennox variable speed air handler with the PureAirâ„¢ Air Purification System. I can get additional specs if needed. My concern is that during the winter months the fan circulates the air within the house to take advantage of the purification system. In doing so, as the air comes through the ceiling registers, it is fairly cold. While I would expect some heat loss as it flows through the attic but I would assume that the air ducts in the attic should be pretty well insulated, correct? Is this normal?