Forced air heat buffer?

abogart · 02-06-12, 08:09 AM

I have been wondering if there would be any advantage to adding an air/water HX with an insulated tank and pump to a forced air furnace. One of the benefits of hot water heat is the ability to add heat storage capacity in the form of accumulator and buffer tanks. Why not do the same with forced air? When the furnace is running, the water is heated by the furnace, storing some of the heat in the water. When the furnace finishes its cycle, the pump and furnace blower remain on, continuing to heat the house with the stored heat. The pump could be set to turn off at a set low temperature, and always on when the furnace is running.

Would there be any benefit to this setup? I can see reduced cycling as a potential gain, increasing furnace efficiency with longer run times. DHW could also be preheated in this manner, as well as adding the capability to grab excess heat from other sources, such as solar, wood, or even a DIY heat pump.

02-06-12, 08:09 AM	#1
abogart Efficiency Afficionado Join Date: Jan 2012 Location: Michigan, US Posts: 68 Thanks: 21 Thanked 6 Times in 4 Posts	Forced air heat buffer? I have been wondering if there would be any advantage to adding an air/water HX with an insulated tank and pump to a forced air furnace. One of the benefits of hot water heat is the ability to add heat storage capacity in the form of accumulator and buffer tanks. Why not do the same with forced air? When the furnace is running, the water is heated by the furnace, storing some of the heat in the water. When the furnace finishes its cycle, the pump and furnace blower remain on, continuing to heat the house with the stored heat. The pump could be set to turn off at a set low temperature, and always on when the furnace is running. Would there be any benefit to this setup? I can see reduced cycling as a potential gain, increasing furnace efficiency with longer run times. DHW could also be preheated in this manner, as well as adding the capability to grab excess heat from other sources, such as solar, wood, or even a DIY heat pump.