Abstract: A combination heat exchanger and blower unit suitable for connection into the breeching between a heater and the stack to admit hot flue gases into the unit. The flue gases enter a fan section wherein the hot flue gases and recirculated gases within the unit are accelerated by a fan. A helical coiled tube heat exchanger is positioned within the unit and is bombarded by the gases which are discharged by the fan. The turbulence created within the unit causes the heated gases to impact upon and to pass between the heat exchanger coils many times at high pressure. The repeated impacts of the heated gases upon the tube heat exchanger breaks down the boundary layer of stagnant gas surrounding the heat exchanger coils and results in greatly increased heat exchange efficiency.