REFRIGERANT SWITCH: A Greenheck DGX-P116 Makeup Air Unit. Greenheck Fan Corp. has begun offering direct gas-fired makeup air units with the lower-GWP refrigerant R-454B. (Courtesy of Greenheck Fan ...

If you buy something, we may earn an affiliate commission. Learn how we test. Party season is an open invitation to step away from your everyday routine because most of us expect extra from our ...