The IN-FORCER™ fresh or combustion air intake system is designed to provide a cost-effective solution to improve poor indoor air quality. Outside air is drawn in through 3-in. PVC pipe and tempered with inside air before being delivered to the room. Other features include a user-programmable timer on fresh air models, and combustion air models interlock with heating equipment to eliminate back drafting.
—Tjernlund Products, Inc.
White Bear Lake, MN