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Heat pump using warm crawl space air, possible?

backintheday

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Feb 7, 2012
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Western Wyoming
Is it possible to use the warm air from my crawl space to heat the house. Even in -20 temps my crawl space stays above 45. How can I use that air to heat the house? Heat pump, mini split? All the heat pumps I see are outside. I really want to run hydronic but from what I'm reading the technology for air to water heat pumps isn't here yet. House has spray foam in the walls and R38 in the ceiling and ICF foundation. Currently use the wood stove with back up electric but on windy days, which are often here, the wood stove smokes us out so I want another options. Throw some ideas my way, thanks all.
 
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Gerald O

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An air-to-air heat pump is going to cool the condenser exhaust air. If you supplied the condenser's source air from the crawlspace it would quickly use up that pre-warmed air. If you exhaust the condenser's air back into the crawlspace then you will be, in effect, refrigerating the crawlspace, and you will quickly lose any heat gain. If you exhaust the condenser to the outside of the crawlspace then fresh outside air would need to be vented into the crawlspace to replace it, thus cooling the crawlspace. Heat transfer from warmer soil surface in the crawlspace will be too low.

It won't work.

Now if you had a solar heated roof and took the source air from a vented roof...
 
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backintheday

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Makes perfect sense. Thank you sir.
Geothermal is the way to go, I've got 10 acres so I might as well use it. Back to the drawing board.
 

pseudorealityx

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USA
The best Air to air heat pumps will still give you ~75% of rated capacity at -13 degrees. At -20, you're maybe looking at half the rated capacity. For what it's worth, it'll still be ~2x as efficient as your strip heater you've got now.

That said, if you could get propane or some other hydrocarbon, that would be best.

Leave the crawl space alone.
 
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backintheday

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Makes perfect sense. Thank you sir.
Geothermal is the way to go, I've got 10 acres so I might as well use it. Back to the drawing board.
 
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larry_g

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oregon
I would figure out why your wood stove is smoking. I've heated with wood for 20 years with no problem. Might I suggest that you provide an outside air source for the stove, or check that your chimney is up to snuff. To test for air I suggest you try a burn with a nearby window or door cracked open. If that cures the smoke then your starving for air. I sometimes have to open a door till the chimney heats and starts drawing properly through the outside air inlet.

lg
no neat sig line
 

Charles (in GA)

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I would figure out why your wood stove is smoking. I've heated with wood for 20 years with no problem. Might I suggest that you provide an outside air source for the stove, or check that your chimney is up to snuff. To test for air I suggest you try a burn with a nearby window or door cracked open. If that cures the smoke then your starving for air. I sometimes have to open a door till the chimney heats and starts drawing properly through the outside air inlet.

lg
no neat sig line

This was my thinking. Something is wrong with the wood stove system. It should not smoke back on you. Fix that problem and you will be much better off.

Charles
 
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backintheday

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Western Wyoming
I do plan on installing a direct air intake and a HRV to try to give the house a positive pressure. When I crack a window there isn't much of a difference. The winds here are strong and there is nothing to slow it down, I have uninterrupted views for miles. The chimney is clean and installed to NFPA standards.I hope the HRV is the ticket.
 
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