Make-Up Air - Thermo Products VH8FA119P60B Installation And Operation Manual

B. MAKE-UP AIR:
Today's emphasis on home insulation increases the probability of inadequate air
supply to the furnace. Heavy insulation cuts off infiltration of outside air, which previously replaced inside
air removed by bathroom, kitchen and laundry vent fans, and air escaping up chimneys. This causes a
negative pressure differential within the home that reduces the supply of air available to the furnace for
combustion and ventilation.
The Spirit Make-Up-Air Control, installs quickly and easily on any warm air heating system, delivers
controlled, fresh air automatically during the winter and a constant supply of clean, fresh air for
comfortable summer living. It resolves the negative pressure differential problem.
6