Heating the Second Floor

[CarpentersCure]

Good morning,

I’m seeking guidance on how to more effectively heat the second floor of our home using our wood stove insert. I’ve attached drawings to help show the layout. Below is the basic information about our house, stove, and current setup.

Location
We live in northern Baltimore County, Maryland, roughly 10 minutes south of the Pennsylvania line. Based on the IECC climate zone map, we’re right on the edge of zones 4 and 5.

Wood Stove
We have an Osburn 3500 insert that I installed last winter. The chimney is on the exterior, and I installed approximately 26’ of .006 insulated stainless-steel liner. I also sealed the smoke shelf/damper void with Rockwool insulation. The stove is located on the first floor of our home.

Current Setup / Information
We have two HVAC systems—one per floor. The first-floor system is turned off, and the upstairs system is set to 62°F just to prevent temperatures from dropping too low. We heat the house exclusively with the wood stove, running it 24/7. I load it around 9 PM and still have a full bed of hot coals at 5:30 AM for the next load.

The first floor stays very comfortable—around 70°F throughout the day, and typically about 67°F in the morning. We keep the first-floor doors closed and use a window fan mounted near the ceiling in the sitting room (where the stove is) to push warm air down the hallway toward the kitchen. This setup works extremely well for heating the entire first floor.

The challenge is getting heat to the second floor. As shown on the drawing, the staircase is located in the foyer and is set around a corner. The foyer itself gets plenty of heat from the stove, and the first-floor thermostat is located there—so I can easily monitor the temperature. However, the warm air seems to stop at that point and does not continue up the stairs. The stairs are a standard straight run with a high ceiling void, not an open landing.

I’m looking for recommendations or ideas on how to move heat upstairs more effectively. Would placing a fan at the bottom of the stairs help? Or a fan at the top pulling warm air upward? Our home was built in 1991, and I’ll soon be adding insulation to the attic to restore any lost R-value. We also recently installed new windows, so I don’t suspect major issues with the building envelope. It seems to be more a matter of airflow.

Thank you for any help or insight you can offer. Let me know if anyone needs more information.

Brandon

 

[stoveliker]

Things work better if you push colder air to the stove. So a fan on the floor upstairs pushing colder air down. It'll be replaced by warm air coming up.

 

[EatenByLimestone]

What temp is upstairs? I only see the downstairs temp mentioned. Is it possible that you’re losing a lot of heat from the upstairs? What is the insulation like in the attic? Walls? Windows?

Are you getting as much heat as you can out of the insert, is there a blockoff plate installed with insulation above it?

 

[Dix]

The wall between the stairway & the living room is closed off, or open?

Welcome to the forums !

 

[DBoon]

I have a two story house - about 1000 square feet on the first floor and about 750 square feet on the 2nd. Stairwell is one room away from the woodstove room (and there is a 5' wide opening to the stairwell room). It's an ideal setup (and similar to yours in terms of stove/stairwell placement and upper/lower ratio of square feet)

2nd floor ceiling (attic floor) is well air-sealed (entire house is <1.0 ACH50), R-60 in half the ceiling and R-75 in the other half. Most windows upstairs are new casement or high-quality new double hung (R-4.5 and tight) and there are two older, original windows with storms (R-2, sealed well). Heat loss upstairs is about half of the downstairs (mostly due to less window square footage and more new windows). There is a heat recovery ventilator that does exert a draft of air down the stairs (intakes are on the first floor, all exhaust is on the upper floor), but I don't think this has too much impact (if I change it to only run 1/3 of the time instead of continuously then the upstairs gets slightly warmer).

Having said all of that, my upstairs will maintain at about 5 degrees cooler than the downstairs with just the woodstove running. If I want 68 degrees upstairs, downstairs has to be 73 degrees. If it drops overnight to 69 or 70 downstairs, upstairs will drop also (and takes all day to heat up again). Mostly, this is ok - bedroom are upstairs and I don't mind them cooler, my office is upstairs but gets heated by me and my computer+monitor and warms up nicely (and gets most direct airflow from woodstove moving heat upstairs). I'll usually run radiant heat in the bathroom floor to keep the bathroom warmer than it otherwise would be. In deep winter, I won't push the woodstove crazy hard and I'll just run radiant heat in the entire upstairs to add a little boost to what wafts up from the woodstove.

Therefore, even if you were perfectly insulated with no leaky windows, your upstairs will not be a warm as your downstairs. You might need a bigger woodstove downstairs or need to run 3 fires a day instead of 2.

Hope this helps.

 

[kborndale]

Put a mini split upstairs.

 

[CarpentersCure]

What temp is upstairs? I only see the downstairs temp mentioned. Is it possible that you’re losing a lot of heat from the upstairs? What is the insulation like in the attic? Walls? Windows?

Are you getting as much heat as you can out of the insert, is there a blockoff plate installed with insulation above it?

The temp upstairs is usually around 63. Regarding the upstairs, the attic is spray-in and the walls are 2x4 since it was built in 1991, not 2x6. They are insulated and the windows are all a new. We are looking into adding more insulation to the attic since the existing is 35 years old.

I do not have a block-off plate install, however I filled the entire void with the Rockwool.

 

[CarpentersCure]

The wall between the stairway & the living room is closed off, or open?

Welcome to the forums !

That doorway is open. It has a door but we don't ever close it.

And thank you!

 

[CarpentersCure]

I have a two story house - about 1000 square feet on the first floor and about 750 square feet on the 2nd. Stairwell is one room away from the woodstove room (and there is a 5' wide opening to the stairwell room). It's an ideal setup (and similar to yours in terms of stove/stairwell placement and upper/lower ratio of square feet)

2nd floor ceiling (attic floor) is well air-sealed (entire house is <1.0 ACH50), R-60 in half the ceiling and R-75 in the other half. Most windows upstairs are new casement or high-quality new double hung (R-4.5 and tight) and there are two older, original windows with storms (R-2, sealed well). Heat loss upstairs is about half of the downstairs (mostly due to less window square footage and more new windows). There is a heat recovery ventilator that does exert a draft of air down the stairs (intakes are on the first floor, all exhaust is on the upper floor), but I don't think this has too much impact (if I change it to only run 1/3 of the time instead of continuously then the upstairs gets slightly warmer).

Having said all of that, my upstairs will maintain at about 5 degrees cooler than the downstairs with just the woodstove running. If I want 68 degrees upstairs, downstairs has to be 73 degrees. If it drops overnight to 69 or 70 downstairs, upstairs will drop also (and takes all day to heat up again). Mostly, this is ok - bedroom are upstairs and I don't mind them cooler, my office is upstairs but gets heated by me and my computer+monitor and warms up nicely (and gets most direct airflow from woodstove moving heat upstairs). I'll usually run radiant heat in the bathroom floor to keep the bathroom warmer than it otherwise would be. In deep winter, I won't push the woodstove crazy hard and I'll just run radiant heat in the entire upstairs to add a little boost to what wafts up from the woodstove.

Therefore, even if you were perfectly insulated with no leaky windows, your upstairs will not be a warm as your downstairs. You might need a bigger woodstove downstairs or need to run 3 fires a day instead of 2.

Hope this helps.

Thank you for the info. It sounds as if we have a similar setup. I am going to upgrade the insulation in our attic since ours is the original spray-in (1991). The windows are new (within the past three years), so I wouldn't expect this being the issue. I am curious how much heat I may be losing through the ceiling since due to the insulation. Thank you, again!

 

[CarpentersCure]

Put a mini split upstairs.

They are much more efficient, so that may be something we look into down the road to take the chill off, if needed. Thanks for the recommendation.

 

[Dix]

That doorway is open. It has a door but we don't ever close it.

And thank you!

I meant is there a wall between the stairway & the living room.

My bad.

 

[DBoon]

The temp upstairs is usually around 63.

I am going to upgrade the insulation in our attic since ours is the original spray-in (1991).

Unless your attic insulation is really bad (i.e. <<R-50), I wouldn't expect miracles with the upstairs temperature increasing much beyond 63. I think you are just (mostly) dealing with realities of what you are going to get with natural convection up a stairway. I had expected the opposite problem - a too hot upstairs and I had considered installing a small ceiling fan in the stairwell middle landing (something I fortunately did not do) to push the air down and keep the upstairs from getting too hot.

I do have radiant floor heat separately zoned in all the rooms upstairs, so I just run that when it gets too cool.

Even though your upstairs is settling in a 63 (a little lower than desired), the reality is that you are probably taking care of 90% of the heat load up there. You might have to deal with the inevitable family complaints about how cold it is up there (something I do not have to worry about).

 

[Murray01]

If you have a fan in the Master Bath try running it. It won’t pull a ton of heat but will help.

 

[DBoon]

If you have a fan in the Master Bath try running it. It won’t pull a ton of heat but will help.

Won't that just pull the heat up and out of the house?

 

[Murray01]

Won't that just pull the heat up and out of the house?

Yes it will. In our case the heat pulled from the house was replaced by heat from the wood stove and solar gain. We only ever ran the bathroom fan in the late morning to evening once the house was warmer than the furnace thermostat setting. The way I looked at it was the “free” heat was exhausting out the bathroom but pulling heat up the stairs and warming the north side of the house with wood stove heat, the south side had ample windows that would supply lots of solar heat.