Anyone Using Their HVAC Air to Circulate Stove Heat?

[Wolfetone]

So I have the central A/C's now covered outside. There is an Auto button and a fan button. The fan button I believe circulates internal air, nothing to do with the outside A/C units, I believe, I could be wrong?????

So my living room is getting up to 85F, and I need to circulate the air, I thought of placing a ceiling fan above the stove to pull the hot air back down and get some circulation going.

Another idea was to use the existing HVAC or central air on the Fan option.......

Anyone using any of these?

I have a 'quiet whisper' circulation fan above the doorway, but I dont see much of an improvement with it in place.

 

[begreen]

Might work if the ductwork is entirely insulated. Can you describe the house floor plan, maybe include a sketch showing where the stove is?

 

[Cory S]

Our home is setup like yours. I would love to cycle the blower fan a few times a day for 20 minutes or so. Our home is basically a two floor ranch. The downstairs cold air return is at floor level. The woodstove is downstairs, but at floor level it only gets up to about 71*, while near the ceiling, it can get as high as 85*. I thought about relocating the cold air return ducting near the ceiling. If I do this, it will pull the heated air in, and circulate it through all the insulated ductwork through out the house.

 

[Jackfre]

So I have the central A/C's now covered outside. There is an Auto button and a fan button. The fan button I believe circulates internal air, nothing to do with the outside A/C units, I believe, I could be wrong?????

So my living room is getting up to 85F, and I need to circulate the air, I thought of placing a ceiling fan above the stove to pull the hot air back down and get some circulation going.

Another idea was to use the existing HVAC or central air on the Fan option.......

Anyone using any of these?

I have a 'quiet whisper' circulation fan above the doorway, but I dont see much of an improvement with it in place.

Actually it is done fairly frequently. Simply run the fan option. It would be interesting to see the air temp entering the Return air and that exiting the supply ducts. The DOE says that in the average US home looses between 18-42% of its energy in duct losses.

 

[Tyler]

When I had a new HVAC system installed in my 1800sqft ranch last year, I had a large 12"x12" air return duct placed above my stove. Thinking when the heat raised and I turned the fan in it would help circulate. Did that for about a week. To me a didn't really seem to tell a difference. Could just be my setup.

Anyone else have any luck with this

 

[ctswf]

I dont have a stove (yet) but one of the manuals I read through while shopping recommend running the central ac fan as you described, and at least one dealer told me some fans can be set to run backwards, sucking the air up the supply ducts.

 

[Cory S]

I dont have a stove (yet) but one of the manuals I read through while shopping recommend running the central ac fan as you described, and at least one dealer told me some fans can be set to run backwards, sucking the air up the supply ducts.

Now this is something I may look into.. The idea is fantastic.

 

[Poindexter]

I tried it one year in North Carolina. One story house dug halfway into a hillside, furnace and uninsulated ducts in the basement, cold air return just behind my woodstove.

Better than nothing, but I think I got more heat into the basement than I did into the bedrooms at the far end of the main level from the stove.

 

[Wolfetone]

Sounds like it doesnt work.

Another idea is to put a ceiling fan above the stove in reverse to blow the hot air downward and circulate it. Another option is to cut a vent hole in the ceiling to the 2nd floor and put in a regular AC vent to make it look proper, my parents did this and it works a treat.

I need to get this hot air out of this room

 

[begreen]

I dont have a stove (yet) but one of the manuals I read through while shopping recommend running the central ac fan as you described, and at least one dealer told me some fans can be set to run backwards, sucking the air up the supply ducts.

?? I think that dealer has been blowing smoke.

Duct heat loss is the main concern. Trying to move 85F warm air from a room and losing 10-20F is going to be unacceptable. Most ductwork is designed for a fairly high differential between the room temp and the duct temp. Typically the hot air coming out of a furnace is going to be around 140F so that it comes out of the far registers at well above room temp, say 110 to 120F. When fuel was cheap duct heat loss was acceptable and uninsulated ductwork was common. Now modern systems, particularly heat pump systems are all sealed and well insulated to avoid these duct heat losses. AC system are also insulated because they often run through hot attics and because cold ductwork will sweat.

How is the house floor plan set up? Is it an open floor plan or is the stove in a closed off room? One thing you could try right away is to put a table or box fan, on the floor outside of the room, blowing cooler air into the room. The displaced cooler air will be replaced with the hotter stove room air. Try it, it works.

 

[toddnic]

Turning on the HVAC system to circulate air does not work well. We use a large fan by the woodstove to circulate the air through the house. We have a 2,400 sq. ft. ranch and the bathroom in the master bedroom (farthest away from the woodstove) does need some auxiliary heat in the coldest months.

 

[Phoenix Hatchling]

Last year we tried the HVAC fan out to circulate air, as we also have a split level ranch. The back bedrooms stayed chillier and the living room with the stove was roasting. Last year with the fan running, things evened out greatly, and while the back bedrooms were not AS toasty as the LR, the temp difference was reduced and brought the temp of the back rooms up about 7 degrees. Comfortable to be in and sleep, whereas without the fan it stayed downright chilly and needed a small electric space heater. Our ducts however have 6 inches thick of insulation surrounding them all so there really is minimal heat loss. Without the ducts being insulated, you will probably will lose all the heat to the attic.

 

[spirilis]

Another way to look at it is, the duct fan does work for dispersing excess heat without resorting to opening windows :D

 

[Phoenix Hatchling]

Another way to look at it is, the duct fan does work for dispersing excess heat without resorting to opening windows :D

If opening a window in winter is going to RAISE your temps in the back rooms, go for it my man.

 

[missedbass]

I dont have a stove (yet) but one of the manuals I read through while shopping recommend running the central ac fan as you described, and at least one dealer told me some fans can be set to run backwards, sucking the air up the supply ducts.

Three phase motors will run backwards if not wired right but that does not mean the airflow will be reversed. Most homes have single phase motors

I dont have a stove (yet) but one of the manuals I read through while shopping recommend running the central ac fan as you described, and at least one dealer told me some fans can be set to run backwards, sucking the air up the supply ducts.

I would stay clear of the dealers who gave you that info!

 

[Lumber-Jack]

So I have the central A/C's now covered outside. There is an Auto button and a fan button. The fan button I believe circulates internal air, nothing to do with the outside A/C units, I believe, I could be wrong?????

So my living room is getting up to 85F, and I need to circulate the air, I thought of placing a ceiling fan above the stove to pull the hot air back down and get some circulation going.

Another idea was to use the existing HVAC or central air on the Fan option.......

Anyone using any of these?

I have a 'quiet whisper' circulation fan above the doorway, but I dont see much of an improvement with it in place.

I use my HVAC unit to circulate the air in my house, it works well. As Begreen said in his first post, as long as your ducts are inside the insulated envelope of the house the air won't be subject to heat losses. Apparently I'm told, in some places they run furnace ducts through un-insulated areas in homes, which to me seems crazy, but I understand it's true.
Most modern HVAC or Heat Pump system controllers have a Fan or Circ. mode for circulating the air around in the house even when the heating or aircon systems are not being utilized. We leave ours on circ most of the year. The circ mode gently and quietly moves the air around in the house which really helps remove the warm stale air upstairs in the summer time without needing to actually turn on the aircon. Also because we have three separate duct entering the stove room from the ceiling the circ mode blows cooler air from from the rest of the house down into what becomes the hottest room in the house in the winter time. It's only logical that this is going to help moderate the temperatures throughout the house.
Results may vary depending on the design of your house and how the ducts are laid out and whether or not they are situated within the insulated envelope of the house.
The one misconception that needs to be dismissed though is that metal ducts themselves are like black holes that continue to suck the heat out of the air and never warm up.

 

[missedbass]

+1 uninsulated ductwork run in uninsulated spaces will result in condensation in the summer and a large heat loss in the winter