Another moving heated air thread....

[wishlist]

I've been using ceiling fans, box fans, corner fans and anything else that blows over the last 5 plus years to try and heat the house a little more evenly. Some work some didn't and some the financial account manager ( aka wife) didn't like tripping over fans at 3am . Why, I haven't the foggiest?

I live in a ranch style house with a 14x 20 addition added on the back with cathedral ceilings and huge windows in the room. The stove is in the corner kinda facing the kitchen. Obviously, the addition stays very warm but moving air back to the bedrooms is challenging. I can turn on the fan only on the forced air furnace and within a hour the thermostat in the hall will climb 5-6 degrees easily. I would prefer not to use this fan if I can help it.

My idea is to buy a 6" inline centrifugal fan that has around 450cfm and install it in the forced air duct that is located 2 feet from the wood stove. I can easily tie this duct into the cold return air side of the furnace, which would pull cold air from the duct in the hall and back bedrooms and blow this cold air 2 ft from the stove. I would think this would help to move the warm air out of the stove room. If this works, I then could hook up a thermostat to control the fan? Any thoughts on this idea?

 

[mellow]

I think you got the idea, move that cold air to the area with the stove and it will be replaced with warm air, it just doesn't like making abrupt turns.

 

[corey21]

I think you got the idea, move that cold air to the area with the stove and it will be replaced with warm air, it just doesn't like making abrupt turns.

Abrupt turns my main problem with moving heat.

 

[Todd 2]

Are there supply and return airs in the addition currently ?

 

[wishlist]

Are there supply and return airs in the addition currently ?

No return air in the addition, only 2 6" supply. The return air vents are in the hallway and bedrooms, farthest from the wood stove. The cold air will definitely come from the return air ducts and be blown near the stove which should put a positive pressure in the addition. Thanks for the help everyone.

 

[Todd 2]

OK, the only thing I would consider is maby a little bigger on your pipe and fan (those small 6" inlines don't do well with my experience with them, you will be pulling return air from the entire duct work system (lots or volume) that is why your furnace blower does good, maby 7 or 8 inch with 600 to 800 cfm, I think you will like the results better.
spend the extra $ on the fan for a better quality they sure are quieter an and less noise vibration transfer in my 20 yrs of the HVAC trade, Happy stove heating. Todd 2
By the way, I have the Know it alls living in this house too !

 

[rottiman]

Rule of thumb to remember, push the cool air to the stove. The harder and longer you try to push heated air away from the stove, the quicker it cools down. In a ranch style house, you probably not be happy when it gets to the farthest end of travel if it is pushed too hard.

 

[Backwoods Savage]

I've been using ceiling fans, box fans, corner fans and anything else that blows over the last 5 plus years to try and heat the house a little more evenly. Some work some didn't and some the financial account manager ( aka wife) didn't like tripping over fans at 3am . Why, I haven't the foggiest?

I live in a ranch style house with a 14x 20 addition added on the back with cathedral ceilings and huge windows in the room. The stove is in the corner kinda facing the kitchen. Obviously, the addition stays very warm but moving air back to the bedrooms is challenging. I can turn on the fan only on the forced air furnace and within a hour the thermostat in the hall will climb 5-6 degrees easily. I would prefer not to use this fan if I can help it.

My idea is to buy a 6" inline centrifugal fan that has around 450cfm and install it in the forced air duct that is located 2 feet from the wood stove. I can easily tie this duct into the cold return air side of the furnace, which would pull cold air from the duct in the hall and back bedrooms and blow this cold air 2 ft from the stove. I would think this would help to move the warm air out of the stove room. If this works, I then could hook up a thermostat to control the fan? Any thoughts on this idea?

What strikes me is it sounds like you have too many fans going. Try one or two and stop there. As for the other idea, I don't think it would work well at all.

 

[corey21]

Does it matter if the fan is blowing on the stove from a distance?

 

[Backwoods Savage]

Not sure how far it will work, We have a hallway and if it gets cold in the far rooms, we sit the fan right at the entry to the hallway and it heats the back rooms fast.

 

[freddypd]

I am going to watch this thread since 1, I am a new wood burner and 2, I have a ranch home and would like to have the heat distributed through the house. Thanks for posting.

Is using my central A/C air handler fan a big waste of electric? The installer thought it would work really well.

 

[Backwoods Savage]

He may be right but from reports we've heard, it does not work well at all and is a waste of electric.

 

[mellow]

Is using my central A/C air handler fan a big waste of electric? The installer thought it would work really well.

It works well at moving cold air, the issue comes into play moving warm/hot air to other parts of the house from the return. You are better off moving cold air from other parts of the house to the stove room.

 

[Backwoods Savage]

That is the key mellow. You can move cold air much easier than moving warm air because the cold is more dense.

 

[begreen]

I am concerned about a lot temperature drop due to heat loss in the ducts. That may negate some of the benfits. Before going complicated, try this first:

For more even heat in the house put a table or box fan at the far end of the hallway, placed on the floor, pointing toward the woodstove. Run it on low speed. It will blow the denser cool air down low, toward the woodstove. The denser cool air will be replaced with lighter warm air from the stove room. Running this way you should notice at least a 5F increase in the hallway temp after about 30 minutes running.

 

[madison]

Is using my central A/C air handler fan a big waste of electric? The installer thought it would work really well.

If the air handler and associated ducting is in an unconditioned space (ie attic) - it will be counterproductive.

 

[wishlist]

Obviously , moving heat is and always will be an issue with us wood burners. I'll try and clear a few things up with my problems.

Blowing cold air, box fan towards addition does work, however, the fan must be placed in not the most desirable location( so says the boss). I tend to agree and I need to keep the other wood stove stuffer happy! If I run the forced air furnace (fan only) that will work quite well but not my first choice.

By using a inline fan and that will draw cold air from the return air side of the furnace and blowing this cold into the stove room would seem to do the job. The runs are in the basement with access to and both runs would be isolated from the other supply lines.

Todd, whats your thoughts on a 8 inch fan with a "Y" on the discharge side of the blower feeding both supply lines into the stove room? Reason is changing the 6" runs in the addition to 8 would not be an easy task. Also, I have found 8" fans with about 500cfm but nothing with more cfm's yet. The fantech 8xl can be speed controlled and draws 1.45 amps.

 

[FanMan]

That is the key mellow. You can move cold air much easier than moving warm air because the cold is more dense.

Actually the difference in density between the cold and heated air is insignificant in this case. However, you'll have less heat loss in the ducts if you're moving cold air through them instead of heated air.

 

[Todd 2]

Hello all, For starters, I think Wishlist wants to booster fan move "cold air" into his stove room, pulling it through his cold air ducts out of the bedrooms an such, letting the stove room heat naturally flow back the hall to bedrooms and such, Were not trying to push "stove heat" through any duct work. The Boss (Wife) does not like the box fans. And you would prefer not to use the furnace blower.
Is this much correct so far Wish ? Just so all of us are on the same page.
Keep helping me out here people, A Know It All, I am not !
Another one of my concerns is with a cathedral ceiling as a heat rise trap will the warm air flow back into the main part of the house OK through a lower entrance ? using a ceiling fan ? Im starting to see why you were using so many fans ?

 

[wishlist]

You got it right Todd however I don't use a bunch of fans rather have tried different fans at various locations. We do use both ceiling fans all the time tho, one large in the addition and one in the adjacent kitchen. When the temps are in the low 30's or so this works fine. Colder nights will not tho.

With regards to the cathedral ceiling, its an open floor plan into the kitchen. I believe its a 10ft opening and also a large opening over the kitchen sink. Funny, I told the wife she can wash dishes and admire the fire. I was in the doghouse for a week!

 

[Todd 2]

My set up is is similar to what you have planed, my stove heat blasts into the basement and up the steps at one end of the house, I installed the booster fan pulling the cold air from the back rooms pushing it into the living room where the heat flows up the steps. ( the hottest room) Now the heat makes its way back to the far end of the house and into the bedrooms alot better. The box fan did good but when I pulled the cold air out of the back rooms they heat made its way into them alot better. The 6 in fan did not do to great so when I installed the 8 in. 600 cfm it worked alot better. Your house Im sure is insulated better than mine so that 500 adjustable should work with a tee, more control with the adj. speed too. 1.5 amp is very low draw also. You are also dumping the cold air where your stove is so it should work better than my set up. Let us know how this works if you choose to go this route.
How much nicer can a guy be giving his wife a beautiful view of the fire while doing the dishes !

 

[wishlist]

Well I've ordered the 8" booster fan and will update this thread when its installed and working( hopefully) .

 

[Mo Par]

My stove's in the basement of a split level house. I have a vent in the floor with a fan. Pulls the heat up nicely.
I did have a little four inch fan but upgraded to a ten fan inch that I snagged out of a dead dehumidifier.

 

[TradEddie]

I spent a lot of time last year trying to use the central air fan to draw warm air out of the stove room, and even when I closed all return ducts except the stove room, it was disappointing. Between leaking ducts, heat loss, and drawing cold air through closed return louvers, the best I could get was 70F coming out the supply registers in other rooms. 70F blowing air feels cold, and will never bring a cold room back up to 70. One day, instead of shutting all my returns, I shut all my supply registers except to the stove room, and the improvement was dramatic. This year I plan to experiment with blocking the return duct in the stove room, and possibly adding a second supply duct. I am also considering a dedicated duct with inline fan from upstairs to downstairs, I have an easy setup to test this idea, but doing it permanently may be more difficult.

TE

 

[egclassic]

I spent a lot of time last year trying to use the central air fan to draw warm air out of the stove room, and even when I closed all return ducts except the stove room, it was disappointing. Between leaking ducts, heat loss, and drawing cold air through closed return louvers, the best I could get was 70F coming out the supply registers in other rooms. 70F blowing air feels cold, and will never bring a cold room back up to 70. One day, instead of shutting all my returns, I shut all my supply registers except to the stove room, and the improvement was dramatic. This year I plan to experiment with blocking the return duct in the stove room, and possibly adding a second supply duct. I am also considering a dedicated duct with inline fan from upstairs to downstairs, I have an easy setup to test this idea, but doing it permanently may be more difficult.

TE

You have to be careful blocking off return air vents and supplies as well. Furnaces are designed for a certain load factor (to breath) and by blocking returns and supplies you can damage your system. I am not an HVAC tech, but I have asked our techs at work about blocking returns and they all told me absolutely do not.There is a reason there are not diverters on the return grills. I do not think my system was designed properly because the largest returns are closet to the furnace and the returns at the back of the house hardly draw at all.
The only time I use my A/C fan is when I overfire my stove and get it too hot in the stove room. (I usually try not to do that, but hey, accidents happen) One of those large returns is directly across from my stove, and I'll agree with you about 70* blowing air feels cold.