Looking for any tips on optimizing woodstove + forced air working together

[ncstar126]

We have a somewhat open floorplan with the kitchen/dining being connected to the living room with a ~8ft opening. The living room hosts the wood stove and has very tall (25'?) 12/12 cathedral ceiling and a loft (open to below) + bedroom (not open to below) upstairs. At the top of the loft there is a return air duct at the top of the wall (the return is close to the ridge beam). The kitchen has a scissor truss ceiling.

Kitchen has the thermostat and tends to be the cold place in the house. Wife does not like this (neither do I really..). I shut off the forced air supply to the living room to redirect as much as possible to the other rooms. However, I'm wondering what to do with the air returns. Our prior house had standard ceilings and bottom/top return vents which we would adjust each season. I'm not sure what to do in this house. Would it be best to let the hot air in the tall cathedral ceiling recirculate or block that highest vent?

The living room also has a large air return at floor level and the kitchen has a large return at the top of the wall.

All the HVAC equipment is in the unheated, uninsulated basement.

Another problem I'm having is that both the heatpump and the woodstove do a great job of heating the house when it's like 32F+ out. Whenever it gets very cold, neither of them do a great job and unless I'm trying _really_ hard the electric resistance heat strips are going on at some point. I think we just needed a bigger stove.

 

[Bobbob]

If your returns and hot air ducts in the basement are not insulated you are wasting your time trying to circulate warm air through them to heat areas other than the stove room. Have you tried using fans to blow cold air from other rooms tword the stove? How many square feet are you trying to heat? How big is your stove?

 

[cahaak]

Insulate your basement, you're getting a lot of heat loss through there. I run my furnace fan continuously on 60% and it does a reasonable job helping to even out the temps.

 

[RockyMtnGriz]

Get your wife a cookbook of recipes for the oven. That'll warm the kitchen right up.

I have a similar home, except that my problem is in the master bedroom. Its poorly insulated floor leaks heat to a poorly insulated garage below. Low passage out of the living room with the 20 ft vault. The bedroom doesn't have an air return, If I need to heat it without using the central furnace, it's fans on the floor. The garage below has plumbing, so it does need the heat it gets, though it would be nice if it didn't get it from the master bedroom and bath. Since insulating the bedroom floor is a net zero for my total heating load, it's still a maybe someday project at best. I did buy a cookbook for warming up the master bedroom, but she left me instead, so that didn't really work! Same thing might happen with the food cooking books I recommended above so take my advice at your own risk!

I'd experiment with blocking the return in the kitchen if it's up high. Of course, you need to make sure you're not starving the blower for air, yada, yada. If it's pulling air from high on the wall there's going to be a cold pool of air attracted into the room from other rooms. Blocking the high kitchen return and maximizing the heated air going into that room should force the cold air back toward the other returns and even out the temps some without fans to trip over.

Insulation is still the right thing to do, and if changing the return works, you're probably still talking about a marginal improvement, but this is something you can try today, and you might find it helps even after the insulation.

 

[ncstar126]

If your returns and hot air ducts in the basement are not insulated you are wasting your time trying to circulate warm air through them to heat areas other than the stove room. Have you tried using fans to blow cold air from other rooms tword the stove? How many square feet are you trying to heat? How big is your stove?

The main floor is about 1700 sqft and we have a Regency F3500. I haven't used a blower from the kitchen/dining side of the house yet.

 

[ncstar126]

Insulate your basement, you're getting a lot of heat loss through there. I run my furnace fan continuously on 60% and it does a reasonable job helping to even out the temps.

Nice, yeah I've been thinking of doing this but it's just such a mess right now. I wanted to start by insulating the rim joist. If I could find a good DIY kit sprayer I would take this on right away.

Further to what Bobobb was talking about, all the air returns use cavities in the framing and I'm afraid quite a bit is being lost to nowhere-land.

 

[ncstar126]

Get your wife a cookbook of recipes for the oven. That'll warm the kitchen right up.

I have a similar home, except that my problem is in the master bedroom. Its poorly insulated floor leaks heat to a poorly insulated garage below. Low passage out of the living room with the 20 ft vault. The bedroom doesn't have an air return, If I need to heat it without using the central furnace, it's fans on the floor. The garage below has plumbing, so it does need the heat it gets, though it would be nice if it didn't get it from the master bedroom and bath. Since insulating the bedroom floor is a net zero for my total heating load, it's still a maybe someday project at best. I did buy a cookbook for warming up the master bedroom, but she left me instead, so that didn't really work! Same thing might happen with the food cooking books I recommended above so take my advice at your own risk!

I'd experiment with blocking the return in the kitchen if it's up high. Of course, you need to make sure you're not starving the blower for air, yada, yada. If it's pulling air from high on the wall there's going to be a cold pool of air attracted into the room from other rooms. Blocking the high kitchen return and maximizing the heated air going into that room should force the cold air back toward the other returns and even out the temps some without fans to trip over.

Insulation is still the right thing to do, and if changing the return works, you're probably still talking about a marginal improvement, but this is something you can try today, and you might find it helps even after the insulation.

Yeah that kitchen return is somewhat high. I didn't really consider that blocking it would start exchanging some air between the kitchen and living room. The goofy part (to me) is that the wall opening between the kitchen and living is only about 8ft high, but they both have those high ceilings, so it still feels like a lot of the air exchange is bound to be cooler air.

 

[RockyMtnGriz]

Yeah that kitchen return is somewhat high. I didn't really consider that blocking it would start exchanging some air between the kitchen and living room. The goofy part (to me) is that the wall opening between the kitchen and living is only about 8ft high, but they both have those high ceilings, so it still feels like a lot of the air exchange is bound to be cooler air.

I wasn't being as clear as I should have been. With uninsulated ducting, etc., it's only going to help if you have your forced air heating running. If you're trying to move the air from the woodstove through ducting in a basement that's uninsulated, as others have pointed out, it's going to be cold by the time it gets to where it's going. I think your best bet to move wood heat to the kitchen is fan(s) on the floor blowing cold air back to the living room. The low passages between rooms just make it that much more difficult. If you have a ceiling fan in the living room, turn it on to mix the hot air down to the level of the doorway.

I have 3 large, vaulted spaces in my house connected by probably 7' high passages into a section of 8' high common "hallway" that has a half-floor above it. I can passably heat my whole house from the stove in the living room, but it takes blowers on the floor forcing the cold air to the living room to do it, and the living room is going to be hot, with everywhere else considerably colder. Plus, it's noisy, drafty, and there's fans cluttering the floor. It's not good, but I can keep things from freezing if I'm working on the central system. As much as I would prefer to heat my home with a butt toasting radiant stove in the living room, even with my HVAC in the heated lower floor, and all my air returns low in the hallway or downstairs, I've learned that it can't be done in a civilized fashion even with the HVAC fan running continuously. If it was 40 or 50 outside, it might work, but the living room is still going to be hot.

With a "not open" floor plan, and high ceilings, if you want it to be wood heat, you should consider a wood furnace, or some other system that will distribute the heat, and you'll need insulation so you can stop heating the outdoors.

 

[RockyMtnGriz]

I'm also currently considering a wood cookstove in the kitchen for a supplement on the cold days and to cook on. You can get an EPA certified cookstove these days with long burn times. The downsides are it's another firebox to tend, because the Kuuma in the basement is still going to have to be running, and every flue wastes heat to the outside anytime it's not being used. And, of course, there's $$$ and firewood in the kitchen too at that point.

I do love cooking on a woodstove though!