Distributing heat in multi-story house with open stairwell

[TwoCoasts]

When I use the woodstove to supplement the HVAC system in my four-story house, I get a substantial heat gradient between floors. I’m looking for solutions to reduce this.

Details: the stove is on the second (main) floor. The stairwell is completely open. The HVAC system is zoned, with each zone having its own vents/returns, and air exchange between the zones happening via natural convection through openings between zones—mainly heat rising up the stairwell. The first floor is one zone. The second floor has three zones. And the third and fourth floors are a single zone. When the stove is in use and all the thermostats set to 68, the first floor HVAC unit is running to heat the first floor, but the second floor can get up to 74, and the third floor—well, let’s just say only lizards would find it comfortable. The main problem is the difference between the first and second floors. So my goal is to get some of the heat the woodstove is producing on the second floor down to the first floor—a challenge, since heat rises, I can’t install ceiling fans, and I can’t change the HVAC system.

I’m thinking of trying a portable fan that pulls air downward, placed on the floor of the first level near the stairwell. Can anyone recommend a fan that can easily be set up to effectively pull air downward? Or other strategies that would work?

 

[stoveliker]

I would think that the only way is to create a through the floor fan.

 

[Murray01]

I like those “box” fans usually 3 speed, added bonus if you have sliding windows they fit in the window to suck/blow air into/out the house. On high they can be noisy.

 

[kborndale]

Heat rises, it's quite hard to get it down. Most people that try to ultimately fail. Unless you run some insulated ducting with a blower it's not really gonna happen. Ceiling fans help a bit but you say you can't put them in. Your best bet is to put a stove on the first floor instead of trying to break the laws of physics.

 

[begreen]

We have an open stairwell with a flat ceiling connecting the living (stove) room, with entry hallway where the open stairwell exists. As a result, our upstairs was overheating by about 5º when the living room was at a comfortable temp. Also, the farther corners of the first floor were not heating well. Too much hot air was rising up the stairwell.

As a test, I created a block using cardboard taped at the ceiling level at the opening where the LR and stairwell connect. We ran the stove for a couple days like this and it made a very nice improvement, keeping more heat downstairs. The next spring, I created a false transom to replace the temporary block. Nothing else was changed, but the upstairs now stays comfortable, with the upstairs notably cooler than before. It's much more comfortable for sleeping now.

This is looking toward the entry from the LR. There used to be one flat ceiling here with no break. Now it has the false transom which block a good portion of the hot air that was convecting upstairs.

 

[TwoCoasts]

Thanks to everybody who commented. Not surprised that it’s likely difficult to do this without some kind of permanent modification like moving the stove, changing ductwork, installing transoms etc, which unfortunately aren’t options in my house.

 

[vbu]

I had the same problem at our house. I ended up installing a pocket door in the stairway upstairs, fixed the problem. We usually leave it cracked or halfway open.