I have a relatively new propane forced air furnace (less than 10 yr old) and a very old AC unit. Both were in the house when we bought it so I do not kno0w their exact specs or history.
Is it possible to configure a dual fuel system with the existing furnace? In other words, can I pull out the AC and replace it with a heat pump for AC and moderate temperature heating while keeping propane for those rare cold spells?
By the way, I live near Raleigh, NC. If I had my druthers I’d put in geothermal, but I am not sure I want to pony up the cash right now.
Thanks, Jeff
Replies
whats common there? just heat pumps? or are there a lot of dual fuel "furnaces"
I see a lot of heat pumps and that is what I had previously. However, I was never 100% satisfied with the heat from it...like everyone says, "it is too lukewarm". The idea of keeping the investment in the propane furnace and putting the heat pump on top of it sounds good to me. If it was to be a full re-do I might put more weight to saving my pennies and going whole hog on the geothermal system.Jeff
AFAIK dual fuel heat pumps are just conventional furance paired with heat pump.
Now depending on the age and type of furnace is might not be easy/possible/practical to do this do to the way that the control work between them.
But I suspect that in 95% of the cases it would be practical to do.
I have such a beast, about a year old. I'm very happy with it.
When you say you have a new furnace and old AC, are the chiller coils for the AC integrated into the air handling assembly of the furnace? If so, I would guess you could upgrade the heat pump without busting up the whole system.
In a nutshell, my new system has a set of heater/chiller coils in the air handler. When in heating mode the pump takes heat from outside and dumps it indoors. In cooling mode this is reversed. Below the coils is a conventional propane-fired heat exchanger for when the pump can't collect enough heat from outdoors. I suspect it would rarely run in propane mode in your mild climate.
Good luck,
Scott.
Always remember those first immortal words that Adam said to Eve, “You’d better stand back, I don’t know how big this thing’s going to get.”