# use furnace in cooling mode to circulate wood stove heat



## bwise.157 (Oct 24, 2013)

I have a Quadrafire 2700i wood insert, installed April 2013 that does great to heat my house.  To improve heat distribution in the house, I would like to run my propane/central air unit in cooling mode to utilize the programmable tstat.  The idea is to have the furnace fan only turn on once a set temperature is reached in the house.  Once the house cools down again, it would turn off.   

So, to get the fan only to run in this manor, I turned off the A/C unit breaker, and disconnected the yellow wire inside the tstat.   This keeps the a/c from running.  

Has anyone else done this?  Will it harm my furnace and/or A/C condenser unit at all?  I have no power going to the A/C unit at all.  It is a simple way to utilize what I have without buying a tstat with a programmable fan mode, as long as it wont hurt any of my other components and i dont have to run my furnace fan 24/7.

thanks.


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## HotCoals (Oct 24, 2013)

Have you actually tried it?
I kind of doubt it would do much but you never know.


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## rowerwet (Oct 24, 2013)

the return on your system is intended to return colder air to the blower, mine is mounted in the floor, most are mounted low on the wall, the air being blown into the rooms won't be the hot air you have near the ceiling.


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## HotCoals (Oct 24, 2013)

rowerwet said:


> the return on your system is intended to return colder air to the blower, mine is mounted in the floor, most are mounted low on the wall, the air being blown into the rooms won't be the hot air you have near the ceiling.


Not to hi-jack but you're right about that I guess but in my house my return vents are only maybe 7 inches from the ceiling.
I don't run any fans but I can actually feel heat come out of my return vents upstairs over the room my stove is in.
Maybe that's one reason my house seems to be really even as far as temp goes..I dunno.


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## burnt03 (Oct 24, 2013)

I've tried it in my place, 2400 sq ft split level.  Have 1 of 2 return vents in stove room at the ceiling.  Didn't seem to work, I seem to get best circulation just by letting the stove room heat up and leaving the heat to travel up naturally.


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## bwise.157 (Oct 24, 2013)

thanks for the quick responses.  my returns are mounted next to the ceiling, so they are actually ideal for this.  running the fan only on the furnace helps even out temps in the house.  my wood insert is on one end of my 2400sq ft cape cod style house, so back rooms are obviously going to be cooler.  i am just trying to run the furnace fan occasionally as the front rooms warm up and not 24/7.  i know newer tstats have options to do this, but i thought using the fan only in cooling mode does the same thing, as long as i am not harming my furnace or a/c unit.  again, a/c unit is completely disconnected from power at the breaker and tstat.


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## BurningBrutus (Oct 24, 2013)

I actually do this.  My thermostat has a fan only mode.  I have it run 24 hours a day, every day.  I do this for 2 reasons.  A) i am connected to a high efficiency air cleaner (Merv 16) and this gives me clean air all the time, especially with a dog and cat.  B) it gives the obvious air circulation throughout the house.  The more air movement the better.  On a side note, my air returns are on the floor in the room where my wood burner is.  I would like to put one higher so see if i can get the hot air to circulate more (hot air rises).  I have a wall that has a hot air return in it, i might cut into it at the top of my wall near the ceiling.  We will see if i get enough nerve to do this.


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## pgmr (Oct 24, 2013)

I used to run the furnace fan to try to distribute the heat throughout the house.  It did even out the temperatures, but the average temperature of the house went down.  When only using the fan on the stove, the rooms farthest away from the stove were several degrees warmer.  Here's the thread describing the testing I did: https://www.hearth.com/talk/threads/interesting-air-flow-test-result.42896/


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## Sprinter (Oct 25, 2013)

You may have a shot at this working if the duct work is insulated or inside the house.  Otherwise, you will lose a lot of heat through the exposed ducts.  That may be why pgmr lost heat overall.

A lot of people try variations of this with varying results.


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## Oregon aloha (Oct 25, 2013)

The last house we lived in I ran a wire around the heat system to the fan with a switch to the low speed on the fan. The original idea was to clean the air with the hepa filter in the duct system during the allergy season. Worked great for that. With the wood stove I had the same heat loss issue, but the house felt more the same temp. room to room and the air was always clean. My ducts could have had better insulation on them and maybe less heat loss. My return air was in the ceiling and my heat vents were in the floor.


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## madison (Oct 25, 2013)

Sprinter said:


> You may have a shot at this working if the duct work is insulated or inside the house.  Otherwise, you will lose a lot of heat through the exposed ducts.



I'll add,  that more often than not, the insulation and integrity of the connections for ducting outside the homes insulated envelope are poor and a major source of heat loss, which is increased by running the fan.

- to the original poster, try doing a search of this forum for other responses to this same question for other responses.


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## jeff_t (Oct 25, 2013)

This setup actually works. The original part of the place is a modular. The pic is taken from in front of the stove, in an addition that is the living room. The return for the downdraft furnace is near the ceiling in the adjacent room. I don't know if it distributes the heat well, but it pulls a huge amount of heat thru that doorway. Residual loss in the crawlspace should keep me from having to run a space heater down there.

Of course, a small fan blowing into the living room does a good job as well, sucking up a lot less wattage.


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## Sprinter (Oct 25, 2013)

madison said:


> I'll add, that more often than not, the insulation and integrity of the connections for ducting outside the homes insulated envelope are poor and a major source of heat loss


Case in point.  When we bought our place, the home inspector came back from under the house with a picture of our supply duct from the furnace.  It had a separation in a joint on the top of a couple of inches.  The whole time the previous owners had the place they were heating the crawl space.  He joked that it's probably the only reason the pipes never froze...


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