The Highest Efficiency Rating Is Found in Condensing Furnaces
Condensing furnaces capture heat that would otherwise be sent up the chimney
Venting efficient furnaces is simple
Furnaces with efficiencies of 89% or above are “condensing” or “modulating-condensing” designs. Condensing furnaces use a secondary heat exchangerDevice that transfers heat from one material or medium to another. An air-to-air heat exchanger, or heat-recovery ventilator, transfers heat from one airstream to another. A copper-pipe heat exchanger in a solar water-heater tank transfers heat from the heat-transfer fluid circulating through a solar collector to the potable water in the storage tank. to condense water vapor in flue gases and capture heat that would otherwise be sent up the chimney. Because flue gases are cooled, they can be direct-vented with plastic pipe rather than piped into a masonry or metal flue. The corrosive condensate from the heat exchanger is ...