Kay Bishop writes:
"You do great service and I thank you as I can not purchase this item in this town so look to you each summer to get my filters for the winter season. Thank you so much!"
All separated combustion units MUST BE equipped with both combustion air and exhaust piping to the outdoors. The unique concentric adapter assembly, required for UDAS heaters, allows for both combustion air and exhaust piping with only one horizontal or vertical penetration hole in the building.