A “counterflow” system pulls in room air at the top of the furnace, warms the air across the combustion chamber and delivers it at the floor level. This gives an equalized floor-to-ceiling temperature.

Direct-Vent Forsaire Counterflow Models include 4007732, 4007731, 6007732, 6007731, 4007332, 4007331, 5507332 and 5507331.

Top-Vent Forsaire Counterflow Models include 6008532, 6008531, 3508632, 3508631, 5008632, 5008631, 6508632, 6508631, 3508232, 3508231, 5508232 and 5508231.