Natural gas space heaters
daestrom wrote:
I just installed a 30K Btu/h natural gas vent-free radiant heater in
a house near Allentown, PA, where kerosine now costs $3.50/gallon
and natural gas costs about $1.50/therm (roughly equivalent)...
... Why does it have the sensor low to the floor
Dunno.
... and why did you install it in front of a window?
That was sort of an accident. It might possibly change.
2.2=60C0.075(wi-wo), so C = 37 cfm, with a heat loss of about 37(70-31.8)
1420 Btu/h, which lowers the heater system efficiency to 93%, compared to
an HHV-based 100%.
70 degF air at RH 50% is about 25.5 Btu/lbm and 31.8 degF air at RH 100% is
about 11.7 Btu/lbm. So the heat loss from 37 cfm is
37*60*.075*(25.5-11.7)=2298 Btu/hr, more like 88.5% efficiency.
Ah yes. I was just thinking about the sensible loss. Then again,
we might build that Coroplast condensing air-air heat exchanger.
So with ventilation to control the humidity, you'll get efficiencies
comparable to a conventional gas furnace.
Higher, I'd say, in this drafty house.
It'll be nice and humid in the house, but with single pane windows you'll
have a lot of condensate and mold growth on the frames.
The owner seems reluctant to add window films or fix the basement puddles...
Nick
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