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Aftermarket combustion air intake control

jduncan Member Posts: 6
In an idle hot water furnace, it is well understood that the furnace itself presents a serious heat loss. Such is not related to combustion efficiency as the burner is OFF (which is often most of the time) --it draws warm air out of the building, heats it with the largest, hottest convection "radiator" in the system and vents it up the chimney.

My question:
Is there an aftermarket control that turns off the combustion air intake when the furnace is idle? I thought of designing one myself, but would prefer one that is tried and tested.

I first ran across such a system about 60 years ago--it was an oil burner manufactured by Timkin. In today's world, such are standard equipment on many or most new furnaces, but how does one retrofit an old furnace?


  • Jamie Hall
    Jamie Hall Member Posts: 23,458
    Field Controls, among others -- several models of draught dampers. Quite common. Some of us talk the efficiency gains (minimal) and love them, some of us regard them as a potential single point of failure at oh dark hundred New Year's Eve in a blizzard and hate them.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England