I am looking for some ideas on how to transfer heat from the main level of my house to the lower level. I am sure someone around this forum has a good idea of how to do it. I have a split level home, the wood stove is on the main level. The lower level of the house is still heated with fuel/baseboard heat. I don't need to heat the whole house with the wood stove (although it would be nice) but there is a crawlspace under the main level that gets very cold in the winter. I would like to pump some warm air 10 to 12 feet down from the stove area into that crawlspace. I would like to find a fan/blower that would take 120 volt and move a decent amount of air. The interior wall of the house where the stove sits is directly above the crawlspace, so I just need to install a vent up above the stove in that wall (where the hot air is) and push the warm air down through the wall between 2 of the studs and it will get to the crawlspace. There is no sheetrock in the crawlspace also. Can anyone give me a link to some products to check out? Any personal experience? Should I install some type of ducting to make sure it is more efficient? Electricity is expensive so I would like a good efficient fan/blower for this. Any input would be greatly appreciated.
I want to transfer wood stove heat to lower level of the house.
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KsWoodsMan
Addicted to ArboristSite
Welcome to AS !
You could use natural convection to do this for you.
In the lower portion of the house install a 3" X 12" vent about floor level in a wall leading to the crawl space. Then install a single walled vent pipe behind the wood stove that goes through the floor and parralell to the hot flue pipe. The heat from the flue pipe will create convection draft through the single wall pipe pulling cold air from the lower level into the crawlspace. The "cold" air will probably be warmer then what was in there to start with. The father the pipe extends down the colder the air it will be drawing out of down there. The taller the pipe is and the more the pipe gets heated by the stove the more air it will draw. It doesnt require electricity and costs only the price of the materials once. Instead of costing you money every month of every year it is used. It is quiet too.
I was surprised how much air gets moved through a 4" pipe just being warmed by the radiant heat given off 3"-4" from my flue pipe of my stove. I noticed a long time ago that the stove didnt quite get the air warm from the bottom of the stove down. I imagined several covers for the stove that would pull air from the floor up around the stove but didnt like how it limited the functionality of the stove.
It was almost by accident that it happened. I had a couple of extra sections and stood them up behind the stove in the corner with an elbow on the bottom. The elbow let it draw air since it wasnt capped off against the floor. In the next few days I noticed the house seemed warmer even though the thermostat still read in the low 70's. I was cleaning it out and spilled a bit of ash. The dust headed straight for the back of the stove which seemed unuasual ATM. I looked under there and sure enough the extra vent pipe was where it was headed for. There was enough of a draft through it that you could easily feel the air moving in front of it.
My next thought was if 4 feet of VP is good , double it ! and get it closer. Made enough of a difference here that the bedrooms stay noticeably warmer and the floors dont have 6"-8" of cold air in the next room from the stove.
I'm sure there will be plenty of ideas out there. Some of them you might even like .
if the studs are open into the basement through the wall just put a small vent at the top of the wall to pull the warm air from the top of the void between the studs
You could use natural convection to do this for you.
In the lower portion of the house install a 3" X 12" vent about floor level in a wall leading to the crawl space. Then install a single walled vent pipe behind the wood stove that goes through the floor and parralell to the hot flue pipe. The heat from the flue pipe will create convection draft through the single wall pipe pulling cold air from the lower level into the crawlspace. The "cold" air will probably be warmer then what was in there to start with. The father the pipe extends down the colder the air it will be drawing out of down there. The taller the pipe is and the more the pipe gets heated by the stove the more air it will draw. It doesnt require electricity and costs only the price of the materials once. Instead of costing you money every month of every year it is used. It is quiet too.
I was surprised how much air gets moved through a 4" pipe just being warmed by the radiant heat given off 3"-4" from my flue pipe of my stove. I noticed a long time ago that the stove didnt quite get the air warm from the bottom of the stove down. I imagined several covers for the stove that would pull air from the floor up around the stove but didnt like how it limited the functionality of the stove.
It was almost by accident that it happened. I had a couple of extra sections and stood them up behind the stove in the corner with an elbow on the bottom. The elbow let it draw air since it wasnt capped off against the floor. In the next few days I noticed the house seemed warmer even though the thermostat still read in the low 70's. I was cleaning it out and spilled a bit of ash. The dust headed straight for the back of the stove which seemed unuasual ATM. I looked under there and sure enough the extra vent pipe was where it was headed for. There was enough of a draft through it that you could easily feel the air moving in front of it.
My next thought was if 4 feet of VP is good , double it ! and get it closer. Made enough of a difference here that the bedrooms stay noticeably warmer and the floors dont have 6"-8" of cold air in the next room from the stove.
I'm sure there will be plenty of ideas out there. Some of them you might even like .
if the studs are open into the basement through the wall just put a small vent at the top of the wall to pull the warm air from the top of the void between the studs
Ok, you have got my attention! This sounds very interesting but since I am unfamiliar with how this works, I'll dummy it down to my level and try to take this 1 step at a time. The cold crawl space is directly under the wood stove so you are saying I would run basically another "stovepipe" right beside the hot one from the stove? This pipe would continue down through the floor into the cold crawl space near the ground where the air is coldest? Then the cold air would want to naturally want to move to the top of the pipe where it is hot, creating the heat transfer? I'll worry about vents and whatever after I get this straight. Thanks for your info, I am really trying to picture how great it would be if this worked without using electricity.
mga
wandering
cold air is heavier than warm air. physics 101.
there is no way hot air will travel downwards by itself. it needs another source to force it down wards. ie: a fan.
there is no way hot air will travel downwards by itself. it needs another source to force it down wards. ie: a fan.
mtfallsmikey
Addicted to ArboristSite
And...
When you supply air to a space, you need to return it...crawlspace=possible Radon?...better off insulating first, foam board around the perimeter walls, 'glass in the joist bays.
When you supply air to a space, you need to return it...crawlspace=possible Radon?...better off insulating first, foam board around the perimeter walls, 'glass in the joist bays.
Rookie1
Addicted to ArboristSite
Im interested too. I know heat rises and all that but would like to see that convection setup in action.
opcorn:
opcorn:urhstry
ArboristSite Operative
I agree with KSWoodsman's concept. The air itself doesn't need to be pushed or pulled because the draft is doing it already. Removing that cold air will pull the warmer air around the home into the void and warm up that area. My uncle tried to explain this concept to me for my home and I didn't get it, nor did I agree, but we put something together and it worked. Go figure.
Ok, I know I want to spray the walls of the crawl space with insulation in the future but I don't think it is going to happen this year. I don't need to heat that area to 70 degrees but we get air temps -30 to -50 degrees for a month at a time. With no heat in that area, I am concerned about pipes freezing. Before I installed the wood stove, all of the baseboard water lines ran through the crawl space which heated it enough to keep it warm. Now the wood stove heats that area of the house so no warm water circulates through the crawl space. I have plenty of wood for the winter and the crawl space isn't that big, the wood stove will take the chill out of there no problem if I can just get the heat down there. I may even be able to keep the floors warmer in the process. Thanks for your help. 
Jkebxjunke
*Politically Incorrect*
how about this... a piece of round duct with a duct fan in it.. have it up near the ceiling and run the pipe through the floor and have a duct fan in it that blows heated air into the crawlspace. since you are going to insulate that in the future... I don't think I would worry about some electric vs the cost of frozen pipe repair. just my 2 cents
and here's a thought.. how about getting some pipe insulation and insulating the pipes?
and here's a thought.. how about getting some pipe insulation and insulating the pipes?
Basica Guru
ArboristSite Member
If you only looking to keep the water lines from freezing, I would just use heat tape and pipe insulation. It does not use much electricity, I would think it would be comparable to a duct fan. You will not have the benefit of a warm floor, but will accomplish your goal.
Scootermsp
ArboristSite Guru
Check your codes!!!
Beware of building codes which might prohibit such an opening between levels as this can permit fire to enter walls and travel from lower to upper level. Make sure you check with your building inspector because if it is prohibited and you have a fire in that area insurance will not pay! Good luck I'm sure someone will have a good solution, there are some brilliant people here!
Beware of building codes which might prohibit such an opening between levels as this can permit fire to enter walls and travel from lower to upper level. Make sure you check with your building inspector because if it is prohibited and you have a fire in that area insurance will not pay! Good luck I'm sure someone will have a good solution, there are some brilliant people here!
Last edited:
Khtsr44
ArboristSite Lurker
Electrical prices
He probably wants to use as little electric as possable.
It is around 20 cents a KWH around here.
He probably wants to use as little electric as possable.
It is around 20 cents a KWH around here.
KsWoodsMan
Addicted to ArboristSite
The idea I had in mind is to use the crawlspace as a "cold air well" of sorts. Realizing that the temps he experiences are going to be much more extreme then I see here in Kansas the idea was to keep the air from falling below freezing in the crawlspace, where his water pipes might be located.
The lower level will naturally be a place for cold air to settle and be harder to heat with the wood stove upstairs, since this area is 2 to 6 feet lower then the heat source. Instead of trying to push air down there which will only rise back up stairs. Why not draw the cold air out of that living space into another area by ducting it back to the heat source using narural convection. If the cold air return line for the wood stove was in the lower level instead of right around the stove itself the return line would be drawing the air out of the lower portion of his home.
MGA you are absolutely correct cold air is heavier. Warm air does rise. No arguements
Cooler air settles to the floor, warm air rises to the ceiling. That's why insulation in the cieilings and attic are important. It helps retain the heat from the ascending warm air at the ceiling and is warming the unused attic space.
Warm air rises, by heating air in the tube it will rise. Drawing in denser air from the crawlspace. The air from the crawl space has to be replaced from somewhere. Cant argue that one either. The 3 X 12 opening near the floor of the lower level that adjoins the crawlspace provides this replacement air. The cool air from the floor of the upper level will settle into the lower level. We cant stop that from happening. We can draw that cold air out of that area moving it back to the warmest part of the house and heating it before it re-enters the living space. This natural convection will keep the coldest part of the air moved out of the lower portion and back into the heating system , the area near the wood stove.
By putting the vent pipe closer to the floor of the crawl space you are pulling the coldest part of the air out of that area. The air above the opening will be about the same temp as the air pulled from the floor of the lower level. This should be warm enough to keep his pipes from freezing. That is, if he is able to heat the upper level to a comfortable temperature.
There is no replacement for insulation, no arguements there of any sort. Insulating the exterior crawlspace walls so this heat doesnt escape into the frozen ground would help tremendiously. No arguements there. What I offered was a suggextion that didnt relly on electricity to achieve getting warmer air to the crawlspace and would effectively warm the lower level with the heat from his wood stove upstairs. It wouldn't be directly heated by the wood stove. The air that moved to the lower level would have someplece to go instead of just settling. It would then be replaced by warmer and warmer air as the cold air was drawn out of the area.
Will it be enough that he won't have to use any additional heat for that area ? I don't know.
If his wood heater is capable of heating that much area he wont have to use as much additioal heat for the lower area.
When you are relying on electricity to keep your pipes from freezing and the power fails what happens then ? The pipes freeze.
Fire Concerns
If fire traveling through the opening between levels is a concern, then duct the entire cold air return from the lower level leading to behind the wood stove. It wont warm the cold crawlspace as well as replacing the cold air there replaced with warmer air. It seems, with a fire down stairs that the smoke/fire would be more likely to travel towards the ceiling, leadeing to the stairway, instead of an opening on the floor.
If fire was such an issue why do we build from brnable resources.
The lower level will naturally be a place for cold air to settle and be harder to heat with the wood stove upstairs, since this area is 2 to 6 feet lower then the heat source. Instead of trying to push air down there which will only rise back up stairs. Why not draw the cold air out of that living space into another area by ducting it back to the heat source using narural convection. If the cold air return line for the wood stove was in the lower level instead of right around the stove itself the return line would be drawing the air out of the lower portion of his home.
MGA you are absolutely correct cold air is heavier. Warm air does rise. No arguements
Cooler air settles to the floor, warm air rises to the ceiling. That's why insulation in the cieilings and attic are important. It helps retain the heat from the ascending warm air at the ceiling and is warming the unused attic space.
Warm air rises, by heating air in the tube it will rise. Drawing in denser air from the crawlspace. The air from the crawl space has to be replaced from somewhere. Cant argue that one either. The 3 X 12 opening near the floor of the lower level that adjoins the crawlspace provides this replacement air. The cool air from the floor of the upper level will settle into the lower level. We cant stop that from happening. We can draw that cold air out of that area moving it back to the warmest part of the house and heating it before it re-enters the living space. This natural convection will keep the coldest part of the air moved out of the lower portion and back into the heating system , the area near the wood stove.
By putting the vent pipe closer to the floor of the crawl space you are pulling the coldest part of the air out of that area. The air above the opening will be about the same temp as the air pulled from the floor of the lower level. This should be warm enough to keep his pipes from freezing. That is, if he is able to heat the upper level to a comfortable temperature.
There is no replacement for insulation, no arguements there of any sort. Insulating the exterior crawlspace walls so this heat doesnt escape into the frozen ground would help tremendiously. No arguements there. What I offered was a suggextion that didnt relly on electricity to achieve getting warmer air to the crawlspace and would effectively warm the lower level with the heat from his wood stove upstairs. It wouldn't be directly heated by the wood stove. The air that moved to the lower level would have someplece to go instead of just settling. It would then be replaced by warmer and warmer air as the cold air was drawn out of the area.
Will it be enough that he won't have to use any additional heat for that area ? I don't know.
If his wood heater is capable of heating that much area he wont have to use as much additioal heat for the lower area.
When you are relying on electricity to keep your pipes from freezing and the power fails what happens then ? The pipes freeze.
Fire Concerns
If fire traveling through the opening between levels is a concern, then duct the entire cold air return from the lower level leading to behind the wood stove. It wont warm the cold crawlspace as well as replacing the cold air there replaced with warmer air. It seems, with a fire down stairs that the smoke/fire would be more likely to travel towards the ceiling, leadeing to the stairway, instead of an opening on the floor.
If fire was such an issue why do we build from brnable resources.
I can't see this plan working at all, I don't believe you'll get warm air to flow down without a fan or duct booster. The stove will draw all the air it needs from infiltration, either from the room it's in or the crawl space - But, you won't get the warm air to 'flow down' to replace the cold, more cold will infiltrate to replace whats being drawn. Warm air in any useable ammount just will not flow down, it needs to be forced.
Crofter
Addicted to ArboristSite
Unless the crawl space is absoulutely sealed against outside air, that is what will be pulled into the crawl space! not the warmed air from the main floor that is expected to to flow down (reverse) into an area of heavier air. In effect you will be creating a vacuum and the coldest air available and at the lowest elevation has the most potential to flow into the crawlspace. Makeup air for combustion has to come from someplace. It comes into your house on the pressure differential between the top of your chimney and the coldest most available air. This pressure differential will be much higher than what you will get from your proposed convection system.
Really I think what you will need to do is pressurise the crawlspace with a fan to keep cold air from collecting there. Then make outside air available directly at your stove instead of having it pulled in at the most harmfull of places.(crawlspace)
Really I think what you will need to do is pressurise the crawlspace with a fan to keep cold air from collecting there. Then make outside air available directly at your stove instead of having it pulled in at the most harmfull of places.(crawlspace)
ASEMASTER
ArboristSite Operative
cold air pushes hot
but a duct fan in the crawl space and have it exit into the room next to the stove this will blow up to the stove and return some of the air back DOWN the staires and back to the fan . I have run this system for the last 5 years and it makes a 10 * difference in the downstairs air temp. garonteed!
but a duct fan in the crawl space and have it exit into the room next to the stove this will blow up to the stove and return some of the air back DOWN the staires and back to the fan . I have run this system for the last 5 years and it makes a 10 * difference in the downstairs air temp. garonteed!
KsWoodsMan
Addicted to ArboristSite
Nope I dont think natural convection will work trying to get it to go down either. I want it to go up. I wanted it to draw the cold air from the downstairs portion of his house. If the cold air isn't allowed to just settle down there but has some place to go ( back to the stove) it will feel warmer down there because the cold air isnt stacking up down there or in the stairway.
I coverd the problem of air infiltration from outside when I mentioned the 3 X 12 register in the wall downstairs next to the floor .
Nope warm air isnt going to go down through the vent pipe into the crawlspace on it's own. That's not even how I thought I had explained it. Warm air is going to draw the cold air up and out of the crawl space. The crawl space needs to have a 3" X 12" register type vent from the room downstairs to the crawl space.
Basic premise: As the air in the pipe, behind the stove, gets heated it will rise ( the air will rise, not the pipe ) . This rising air will draw cold air from the crawl space and be replenished by the cold air next to the floor of the lower level from through the register/vent/return installed.
Simple convection applied to a larger area than a single room. We arent talking about pulling combustion air from the crawlspace. I was talking about recurculating air through his house to more effectively warm the lower level by putting in a cold air return to his wood stove's heating area. Not to the combustion chamber.
He needs a cold air return from the lower level returning air to the wood stove. He wants to warm the crawl space to keep pipes from freezing. If I was doing it I wouldnt want to hear a fan or worry about the electricity going out. I would put it in just as I described as a cold air return from the lower level of his splitlevel home to behind the woodstove.
If you thought I meant for the vent pipe to barely penetrate above the floor behind the stove think again. I mentioned that it needs to stick up and run parralell to the flue pipe to be heated by it. The higher and closer the better. The heat in the flue pipe is considered wasted heat once it exits the living area. I'm not trying to recover all the heat from it and introduce a creosote problem. Just recover enough of it to create a draft to pull cold air from a lower level than the bottom of the stove.
If you want a fan to push air down there put one in or set it ar the top of the stair and try pushing it down there. Let me know how that works for you. I have an aversion to the noise, was why I thought of using natural convection to draw cold air out of his downstairs, warm it behind his stove and keep doing it without electricity.
I'm sorry if I am not able to explain it well enough that it has become a question of if warm air rises or falls. We all agree it rises. What is so hard to understand that it will rise up the 6 - 8 foot vent pipe behind the stove and pull cold air from the crawl space? The air that is being drawn from the crawlspace gets replenished through the 3 x 12 register vent in the wall of the room that adjoins the crawl space. As this cold air from down stairs gets pulled out of that room it gets replenished by warmer air from the upper level where the wood stove is located. The wood stove is heating the air in the room and the air that is rising up the vent pipe. This rising air is drawing more air from the crawl space. Which starts the cycle over again. As the air in the crawl space gets warmer, the heated vent pipe will draw it from down below easier.
Warm air rises, cold air falls. Make the rising air work for you. Have it pull up cold air that settles downstairs.
Here goes nothing. I will try explaining this in reverse. After that , I am done, If you dont think the warm air will rise then put a fan in there and force it against its will to the cold room down stairs.
You heat air from the wood stove it travels through the house and cools. As it cools it settles in the lowest part of the house. Which is down stairs from the wood stove. By puttin in a register at the bottom of the wall down stairs, The wall that adjoins the crawlspace, and a hole just behind the wood stove we now have a path for the air to travel. We just dont have any force to move it. Put some vent pipe in the hole. Heat the top of the vent pipe with the wood stove or hot flue pipe and the warm air in the pipe will start to rise. As the air that rises comes out of the pipe it cools and goes through the house and back down stairs where it is drawn into the register and into the vent pipe again. It does this untill stove isnt making enough heat to create a sufficient draft in the vent pipe to continue moving air.
The down stairs will be warmer because we are moving the cold air out from there back to the heated area of the woodstove. The crawlspace will be warmed keeping his pipes from freezing. It might not be warmed to 75 degrees but it isnt a living area and as long as the pipes don't freeze , it is warm enough.
KsWoodsMan
Addicted to ArboristSite
Your post wasnt there when I started my reply
+1
My idea was to use natural convection. To do for free what you have the fan doing. I didn't want to force heat down, but to draw out cooler air. Just like you said without the fan.
+1
My idea was to use natural convection. To do for free what you have the fan doing. I didn't want to force heat down, but to draw out cooler air. Just like you said without the fan.
logbutcher
Addicted to ArboristSite
Nailed it TC .
Why waste heat where you don't need it ?
It will not be a waste of heat if I am also keeping the floors warmer. I wouldn't mind warmer floors when it is -30 to -50 degrees outside. If I was going to waste any heat it would definetly be the wood heat since it is way cheaper than fuel or electricity. Insulation alone is not going to take care of this problem, that is why I am looking for something more.
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