How to spread the heat around?
November 13, 2008 4:47 PM Subscribe
Just installed a pellet stove..The heat is concentrated in the room where the stove is. Have a big fan in the doorway, but it is not drawing the heat out of the room.
How do we spread the heat around? How do you maximize air flow throughout the house? Any techniques or concepts we need to understand other than heat rises? Are there any websites devoted to this problem? Any suggestions?
You've got think in terms of circulation loops. Imagine a room containing your stove with a single door. You could put a fan in that doorway but it isn't going to do much good because the air getting pulled out of the room by the fan has to be immediately replaced and the only source is right around the fan. Your circulation system ends up being localized right around the fan.
What you need is a way to move air from the cold rooms into the stove room and to move the warm air from the stove room into cold rooms. With that, you'll have circulation. If you've got a central air-conditioning system, you might run it in "Fan Only" mode just to get the air in the house circulating. It will get pulled into the central intake and then get blown into all the other rooms through the ducts. If you can move air from the stove room to the central intake, you'll be set. Otherwise, try to think of some circular path for air to move through the house, including through the stove room, and set up fans to help make it happen.
posted by LastOfHisKind at 5:23 PM on November 13, 2008
What you need is a way to move air from the cold rooms into the stove room and to move the warm air from the stove room into cold rooms. With that, you'll have circulation. If you've got a central air-conditioning system, you might run it in "Fan Only" mode just to get the air in the house circulating. It will get pulled into the central intake and then get blown into all the other rooms through the ducts. If you can move air from the stove room to the central intake, you'll be set. Otherwise, try to think of some circular path for air to move through the house, including through the stove room, and set up fans to help make it happen.
posted by LastOfHisKind at 5:23 PM on November 13, 2008
You don't need a big fan in the doorway, you need a small fan up near the ceiling. Call any seller of wood stoves in your area; they can tell you what to get.
posted by languagehat at 5:41 PM on November 13, 2008
posted by languagehat at 5:41 PM on November 13, 2008
You probably have your fan sitting on the floor, which means it's blowing cold air, not hot.
posted by Class Goat at 5:46 PM on November 13, 2008
posted by Class Goat at 5:46 PM on November 13, 2008
Seconding languagehat. DH and I just installed a couple of Sand Hill Super Quiet Fans and they seem to move the heat around nicely.
posted by MonkeyToes at 5:52 PM on November 13, 2008
posted by MonkeyToes at 5:52 PM on November 13, 2008
When I was shopping for a gas insert fireplace, I saw some clever fans that combined a narrow metal stand with a top that resembled a heatsink for a CPU. In between was a thermocouple connected to a fan. You set it on your stove and power the fan by the temperature difference between the top and bottom. Not nearly as powerful as a ceiling fan, but good to move some heat around a little. Sorry if that's not descriptive enough; let me know if you're interested in more detail.
posted by sapere aude at 6:08 PM on November 13, 2008
posted by sapere aude at 6:08 PM on November 13, 2008
A large, low speed fan on the floor in the doorway, blowing air from the cold rooms
into the heated room induces a reciprocal motion of warm air near the top of the door
into the cold rooms.
Aiming it a little toward the floor reduces the tendency of the fan to form a local torus of
uselessly circulating air. The natural stratification of air by temperature (cool by the floor,
warm above) also reduces this tendency.
Ceiling fans, operating in the reverse of the direction that you would want in summertime,
will even out the temperature in a single room.
posted by the Real Dan at 6:12 PM on November 13, 2008
into the heated room induces a reciprocal motion of warm air near the top of the door
into the cold rooms.
Aiming it a little toward the floor reduces the tendency of the fan to form a local torus of
uselessly circulating air. The natural stratification of air by temperature (cool by the floor,
warm above) also reduces this tendency.
Ceiling fans, operating in the reverse of the direction that you would want in summertime,
will even out the temperature in a single room.
posted by the Real Dan at 6:12 PM on November 13, 2008
This fan is what sapere aude is talking about in case you are having trouble googling it.
posted by saucysault at 8:13 PM on November 13, 2008
posted by saucysault at 8:13 PM on November 13, 2008
Reversible ceiling fans? Why would you want it reversed? Completely unnecessary.
posted by ryanrs at 10:51 PM on November 13, 2008
posted by ryanrs at 10:51 PM on November 13, 2008
I have to disagree, ryanrs. If a ceiling fan is pushing down in a warm room, the air it pushes down just seems to rises right back up again. If it's pushing up, it sets up a loop with air traveling out along the ceiling, cooling as it goes, sinking down the walls and eventually getting sucked back up. On the way a fair amount of heat leaks out the doorways, drawing cold air in along the floors from the rest of the house. At least, thats how it seems to work in my house.
posted by bricoleur at 3:42 AM on November 14, 2008
posted by bricoleur at 3:42 AM on November 14, 2008
If you've also got a forced air furnace then, depending on how the thermostat is wired, you may be able to run the furnace blower even when the furnace isn't generating heat. That might do a better job of redistributing air and heat around the house than anything you do in the room where the stove is located. In any case, I think LastOfHisKind makes the critical point here. Regardless of whether you use fans or rely on convection alone, You need to think in terms of complete loops. You want hot air going out of the room and cool air coming back in. Since the warm air will be closer to the ceiling, a fan in the doorway at floor level should point into the room, not out.
posted by jon1270 at 4:00 AM on November 14, 2008
posted by jon1270 at 4:00 AM on November 14, 2008
MonkeyToes was not talking about a ceiling fan. See his/her linked item.
posted by megatherium at 4:48 AM on November 14, 2008
posted by megatherium at 4:48 AM on November 14, 2008
I just added the part about the reversible ceiling fan because of the palpable difference
it makes in the how comfortable a room is, when the room is heated by a woodstove.
The difference is probably more noticeable if the walls are not very well insulated, or if
there are a lot of windows in the room.
If you're heating a room with an airtight fireplace or pellet stove, it's a handy trick.
posted by the Real Dan at 11:11 AM on November 14, 2008
it makes in the how comfortable a room is, when the room is heated by a woodstove.
The difference is probably more noticeable if the walls are not very well insulated, or if
there are a lot of windows in the room.
If you're heating a room with an airtight fireplace or pellet stove, it's a handy trick.
posted by the Real Dan at 11:11 AM on November 14, 2008
Response by poster: Thanks to all for all the great ideas. As for now, we are putting up one of the little corner doorway fans..The ceiling in our room is way too low for a ceiling fan. Tonight is supposed to be cold..Wish us luck!
posted by AuntieRuth at 2:20 PM on November 16, 2008
posted by AuntieRuth at 2:20 PM on November 16, 2008
Response by poster: Thought I would take the time to update if anyone is following still around...cut a register in the ceiling from one room away from the stove up into a bedroom..added vornado fan pointing into the room which sucks a lot of the cold air coming down the stairs and shoots it into the room. Also slow box fan stacked high to shove the heat out of the room. That room still averages about 82-84.
Temperatures upstairs about 70 through most of the upstairs, averaging mid 60's in the farther parts of the house....Used 80 gallons of oil so far this year...
Here's the bad news...we were hit by the ice storm and lost our power...no pellet stove at all..we'll probably start looking for a generator..Probably have to post for help in how to operate it!!!
posted by AuntieRuth at 9:59 AM on December 17, 2008
Temperatures upstairs about 70 through most of the upstairs, averaging mid 60's in the farther parts of the house....Used 80 gallons of oil so far this year...
Here's the bad news...we were hit by the ice storm and lost our power...no pellet stove at all..we'll probably start looking for a generator..Probably have to post for help in how to operate it!!!
posted by AuntieRuth at 9:59 AM on December 17, 2008
This thread is closed to new comments.
posted by Dr.Pill at 5:01 PM on November 13, 2008