Wood stove as aux for geothermal

[Elbinwyp]

I am working with an engineer on designing a geothermal system with wood heat as auxiliary. Our plan is to not install the electric resistance heating elements and the wood stove truly be the aux. The house is a 2000sf, early 1900's farmhouse in NW Ohio. 1400sf downstairs, 800 sf upstairs. The wood stove will be installed in the existing fireplace on the first floor.

How should I size the wood stove? If I was planning on only heating with the stove I would be looking for a 3 cu ft firebox. My heating demand is ~60,000Btu/hr. The water furnace series 7 we have chosen will provide 40,000 Btu/hr at the coldest point in the winter.
Putting in a small stove goes against everything I have read on Hearth about choosing a stove size. Is a ~3 cuft stove way too large?

 

[Jags]

You can light a small fire in a big stove but not the other way around. I question why you wouldn't include the heating element in the geo. If it doesn't need to be used, it doesn't turn on - no problem. It would sure be nice to have as plan "c". Illness, unexpected travel, what have you, can bring around conditions you may not see coming. Personally, I would install it.

60,000 btu/hr is a pretty fair heat load for a stove (like if the tricity goes out for a week.) Go big.

 

[razerface]

i use a propane furnace for back up instead of the electric resistance. My geo is a separate unit, you still need the air handler,, so your air handler will be in the wood furnace, or the geo? My geo is only 24 x 36 x 36 (from memory, not a tape measure) and the propane furnace looks normal size.

My wood stove is separate. I think the backup #1 should be automatic,,,unlike a wood stove.

Edit: for instance,, when it gets under 15 degrees, my heat is turned over to the propane. How will your geo turn it over to wood if you are not there to start the fire and load it?

 

[Elbinwyp]

The thought behind not installing the electric resistance was that in order for the freestanding wood stove to truly be the aux heat for the geo (thus being included in the 30% tax credit) the electric resistance could not be included. The house currently has electric radiant heating coils in the ceilings that could be set at a low temp if we were to leave. Not ideal but my "Plan C"

 

[moey]

I would suggest still getting a electric backup they are under $1000 installed. You can essentially program them out with the thermostat or shut them off at the breaker. They will save your but if your on vacation and the geo system locks out for some reason.

I would suggest insulating your house as well as possible and choose the smallest system they move a lot of CFM.

 

[Jags]

Ahh..that does make a difference.

Take it from a 1800 sqft 1895 farmhouse owner in Northern IL...get a big stove, 3 cuft at a min.

 

[moey]

No way a wood stove is included in your 30% credit. Recent ruling ductwork is not included anymore either.

(broken link removed)

 

[moey]

http://www.irs.gov/pub/irs-drop/n-13-70.pdf

.04 Geothermal Heat Pump Property.
Q-31: A taxpayer contacts a seller to inquire about the installation of a geothermal heat
pump to heat his home. The seller/installer informs the taxpayer that the following items
must be installed in addition to the geothermal heat pump: heat exchange equipment in
the ground outside of the house, a distribution system for the home, and a back-up
emergency heating or cooling system. Which of these costs, if any, are eligible for the
§ 25D credit?

A-31: Only the cost of the heat exchange equipment in the ground outside the house
can be eligible for the § 25D credit. The costs for the distribution system for the home
and a back-up emergency heating or cooling system are not eligible for the credit
because they are not incurred for qualified geothermal heat pump property. Section
25D(d)(5)(B) defines qualified geothermal heat pump property as any equipment that (1)
uses the ground or ground water as a thermal energy source to heat the dwelling unit or
as a thermal energy sink to cool such dwelling unit, and (2) meets the requirements of
the Energy Star program in effect at the time that the expenditure for such equipment is
made. Section 25D(e)(1) provides that expenditures for piping and wiring to
interconnect qualified property to a dwelling unit are eligible for the § 25D credit.
However, nothing in § 25D extends the credit to other auxiliary equipment such as
distribution systems within the dwelling unit or backup emergency heating and cooling
systems.

 

[Elbinwyp]

Interesting

http://www.irs.gov/pub/irs-drop/n-13-70.pdf
.04 Geothermal Heat Pump Property.
Q-31: A taxpayer contacts a seller to inquire about the installation of a geothermal heat
pump to heat his home. The seller/installer informs the taxpayer that the following items
must be installed in addition to the geothermal heat pump: heat exchange equipment in
the ground outside of the house, a distribution system for the home, and a back-up
emergency heating or cooling system. Which of these costs, if any, are eligible for the
§ 25D credit?
A-31: Only the cost of the heat exchange equipment in the ground outside the house
can be eligible for the § 25D credit. The costs for the distribution system for the home
and a back-up emergency heating or cooling system are not eligible for the credit
because they are not incurred for qualified geothermal heat pump property. Section
25D(d)(5)(B) defines qualified geothermal heat pump property as any equipment that (1)
uses the ground or ground water as a thermal energy source to heat the dwelling unit or
as a thermal energy sink to cool such dwelling unit, and (2) meets the requirements of
the Energy Star program in effect at the time that the expenditure for such equipment is
made. Section 25D(e)(1) provides that expenditures for piping and wiring to
interconnect qualified property to a dwelling unit are eligible for the § 25D credit.
However, nothing in § 25D extends the credit to other auxiliary equipment such as
distribution systems within the dwelling unit or backup emergency heating and cooling
systems.

Interesting. Thanks for the information. This is certainly different from what I am being told.

 

[moey]

Interesting


Interesting. Thanks for the information. This is certainly different from what I am being told.

Its pretty recent. I was even planning on including the dirt I had brought in to landscape afterwards. Haven't decided what Ill do my system was not broken down to the individual components.

 

[Dave A.]

If you already have the electric backup in the ceiling radiant system, can't really see the need for resistance elements in the heat pump system (especially if they can be added later on should you want them). Just keep the radiant system set to a low temp to work as a true auto backup (even when you are there). And go with a larger 3 cf wood stove, (my opinion).

 

[razerface]

well, the ceiling could be wired to the geo, so that it becomes the backup? That's what those fancy thermostats are for.