Cold Air Returns

I was wondering how important these are on a supplemental stove installation? My house has 2 stories, with the stove on the 1st floor. Most of the heat radiates up the stairwell and gets dispersed to the rooms. At the extreme opposite end (upstairs hallway) of the stairwell, is where the coolest temperature is.(Approx. 16' from the other end)However, directly below that end, is the area where the stove is downstairs. (Off to the side about 6'.) My upstairs hallway has an "inactive" floor grate, that at one time in history, must've been used for heat? Unfortunately someone Sheetrocked over the original beadboard ceiling in the downstairs livingroom and covered it up. So me and my "brilliant ideas decided to cut open the sheetrock ceiling with a matching hole to the upstairs floor grate (8"x12"), to allow the stagnant heated air to "radiate" up into the cold end of the upstairs hallway. Trouble is, "IT WON"T RISE". Here is a rather crude sketch, if it'll clear up any misunderstandings of my babbling descriptions.


Someone I work with mentioned cold air returns, and it seems there might be something to it. If the rising hot air at the platform end of the upstairs hallway is "over-powering or pressurizing" the little floor grate,I could see this being a problem. I was thinking of installing a bathroom ceiling fan in the floor grate to assist in getting hot air up there. Any thoughts from the masters?

Nothin ventured, nothing gained Joe. You're the only one that knows what your house is doing. Yes, air return is important--as for the why's, where's & what have you's--you're basically on your own:)

"On my own, Fred!?" (I'm sooo afraid)

Takes a long time to wear out a hammer, so don't be afraid. Bash enough holes and the heat will circulate.

I have done air circulating scenarios at my home and some fans are better than others. Bathroom fans can be loud and use up a lot of juice, try one of these: http://www.sandhillwholesale.com/fans-controllers ... -8_49.html

they are about one forth the price as well!.....get two there small

Usually, and just usually, you duct the colder air down to about 2 Ft above the downstair floor, so near the stove but not over it, maybe if possible at the back or side of the stove..
As I can see, warm air is fighting the heavier cold air. Just try to sent the cold air as mentionned to create a natural air loop and see the results. You can use scent stick to ""see"" the air path.

The cold air in that upstairs area is fighting with the warm air at the ceiling level downstairs. if you had a duct from the first floor ceiling to the floor the cold air could drop. Or if you had a duct from the floor of the upstairs toward the ceiling the hot air would rise.

Something similar in my ranch house...i have a floor register in the back bedroom, coolest room in the house. The stoker is in the basement. I have flex duct coming off the floor register dropped to the floor of the basement and the cold air comes out of that flex duct pulling the warmer air into the back bedroom. It makes about a 4* difference back there. Without the flex duct the warm air in the basement wouldn't rise through that floor register.

too slow on the keyboard....norcan beat me to it.....

titleist1 wrote:The cold air in that upstairs area is fighting with the warm air at the ceiling level downstairs. if you had a duct from the first floor ceiling to the floor the cold air could drop. Or if you had a duct from the floor of the upstairs toward the ceiling the hot air would rise.

Something similar in my ranch house...i have a floor register in the back bedroom, coolest room in the house. The stoker is in the basement. I have flex duct coming off the floor register dropped to the floor of the basement and the cold air comes out of that flex duct pulling the warmer air into the back bedroom. It makes about a 4* difference back there. Without the flex duct the warm air in the basement wouldn't rise through that floor register.

too slow on the keyboard....norcan beat me to it.....

probably the only place I can beat you

joeq you can try to push the heated air into the upstairs with the fan or pull the cool air down with the same fan! BRILLIANT

I'ld prefer to use the "natural" (non-electric) method if possible. I like the ducting possibilities, but not sure of the best method. The upstairs floor grate is approx 4' away from a closet with a curtain for a door. (Another unfinished "to-do" project). On the floor in this closet is a chaseway I built that houses a vertical hot air duct (for the oil furnace) from the cellar. It's a thin plywood box, that runs through the downstairs kitchen area to the cellar. If I were to cut an 8" square hole in it, (in the upstairs "open" closet,) and cover it with a grate cover, do you guys think that would allow a better flow? Or does the return air, need to end up back near the stove?

[quote="joeq"]I'ld prefer to use the "natural" (non-electric) method if possible. I like the ducting possibilities, but not sure of the best method. The upstairs floor grate is approx 4' away from a closet with a curtain for a door. (Another unfinished "to-do" project). On the floor in this closet is a chaseway I built that houses a vertical hot air duct (for the oil furnace) from the cellar. It's a thin plywood box, that runs through the downstairs kitchen area to the cellar. If I were to cut an 8" square hole in it, (in the upstairs "open" closet,) and cover it with a grate cover, do you guys think that would allow a better flow? Or does the return air, need to end up back near the stove?[/quote]

Return air near the base of the stove could be used for combustion for the fire therefore it is best, BUT if you can do a smoke test with incense or cigar, cigarette, or a smoke test devise (local hardware store purchase) you can tell which way your air currents move and piggy back on it.
My stove is approx 35 ft from the bedrooms, it makes a big U turn through the living room and down a hallway to the bedrooms. I simply put a small, low watt, high speed fan in the floor of a linen closet with a louvered door pulling cool air into my basement and the warm air from afar fills the void and the other end of the house. Living room 74*- 76* and the bedrooms 68* and my home is brick and block with sheet rock, no insulation!
The other benefit is if I choose to fire up the stove in the basement that fan in my linen closet is directly above and in front of the basement stove which blows heated air into the cold air return ducts upstairs, Win,win ...30 cents a day to run the fan!

It's hard to say what exactly is going to work good enough ,but I thought back to how the old houses were set up with registers before forced air . Coal furnace in the basement,HUGE grate over it ; possibly bigger than 4'x4'-- didn't think to measure it back then. Through the ceiling into the second floor rooms were registers about 12"x12" , with forced air we have down sized the registers & to do the natural air transfer again,you will have to go back in time,just my .000001,good luck ! Bigger is better in this case. I should add that those old time registers had no duct work hooked to them,they just filled the hole in the floor,you could see thru them so positioning could be critical.

Yes WH, that is my situation living in a 120 year old home. The registers are original and big and my convection only cold air return works great. This enables me to simply HEPA filter the incoming air to the AnthraKing stove without big ugly ducting. Hey, it just worked through windchills of -20* and that is good enough for me. Strangely, the colder it got the better it worked. OK, OK, the planet got a little warmer but it could use it right now. Of course, the other side of the coin is that energy efficiency was not the original builders strong point. Warm and very cozy thanks to "Mindless overkill is always a good starting point." So perhaps I use 10% more coal that I should do, I'll save the money elsewhere.