Finned Tube heat exchangers are most commonly used for forced air heating and cooling systems, such as with indoor and outdoor wood furnaces, boilers, and stoves.These units rely on air-to-air heat exchange through evaporator units similar to those used for air conditioners. Finned Tube can also be suitable for liquid cooling applications. Copper is specified in supply and return manifolds and in tube coils. Finned Tube heat pumps have been used for residential and commercial heating and cooling for many years.