Good morning to all from Denny and Ida and HAPPY NEW YEAR, I want to see if any one on this forum has a perfectaire fresh air exchanger in there home. We have an older model (model # 100) in our home and have not used it. I would like to start utilizing the unit but I would like to put a new filter in it before we do start using the unit. I have looked on the internet to see if I can find it , but no luck. the filter is about a 8x8x8 block filter that is in the unit. If any one has a unit in there home with a filter like this please let me know. PERFECTAIRE FRESH AIR EXCHANGER thank you!!!