Nate R
Member
Did a heat loss calculation in ResCheck (Free Program for checking whether a houses' insulation and such will meet code)
Also did the same calculation in another program.
I come up with about 32000 BTU of heat loss on my home at the recommended design temperature of -10 F.
My Natural gas forced air furnace is 80% AFUE, and rated at 70000 BTU in, so it's 56000 BTU out.
This seems to line up with our experiences last year. Never was the furnace anywhere near being on even 45 minutes out of an hour. I'd bet it was much less. I wonder how much money I'm throwing away by shorter cycles?
Interestingly enough, the next model down is 45000 BTU in, and 36000 out with 2 burners instead of 3. That appears to be the only difference on the spec sheets. Out of curiosity, is there any danger in plugging the orifice for one burner? (Which would turn my 56000 BTU into about 37000) I'm assuming that would increase the gas pressure at the other 2 burners? Or is there a regulator in the system that prevents this? I don't think I would actually do this, but the thought crossed my mind.
Also: I'll be adding an addition to the home, as I've discussed elsewhere. With MANY improvements to the existing home (New windows, floor insulation, more attic insulation, Tyvek, etc) and with the addition, my total heat load is around 37000 BTU.
I was thinking of heating the addition independently. But, IF I could find a way to get a duct to the addition, I start to wonder. With 56000 BTU out, I would still have 50% more than I need. With 36000 BTU out, I'm a bit short. What would you do?
If I DO heat the addition separately, I can get a new furnace for $650. I was going to spend about that much on a heater for the garage. I could get the smaller furnace for the main part of the house and move the current one into the garage.
Also did the same calculation in another program.
I come up with about 32000 BTU of heat loss on my home at the recommended design temperature of -10 F.
My Natural gas forced air furnace is 80% AFUE, and rated at 70000 BTU in, so it's 56000 BTU out.
This seems to line up with our experiences last year. Never was the furnace anywhere near being on even 45 minutes out of an hour. I'd bet it was much less. I wonder how much money I'm throwing away by shorter cycles?
Interestingly enough, the next model down is 45000 BTU in, and 36000 out with 2 burners instead of 3. That appears to be the only difference on the spec sheets. Out of curiosity, is there any danger in plugging the orifice for one burner? (Which would turn my 56000 BTU into about 37000) I'm assuming that would increase the gas pressure at the other 2 burners? Or is there a regulator in the system that prevents this? I don't think I would actually do this, but the thought crossed my mind.
Also: I'll be adding an addition to the home, as I've discussed elsewhere. With MANY improvements to the existing home (New windows, floor insulation, more attic insulation, Tyvek, etc) and with the addition, my total heat load is around 37000 BTU.
I was thinking of heating the addition independently. But, IF I could find a way to get a duct to the addition, I start to wonder. With 56000 BTU out, I would still have 50% more than I need. With 36000 BTU out, I'm a bit short. What would you do?
If I DO heat the addition separately, I can get a new furnace for $650. I was going to spend about that much on a heater for the garage. I could get the smaller furnace for the main part of the house and move the current one into the garage.