Newbie needs help sizing stove for funky house

[siddfynch]

Hello,

Have been lurking for awhile as I research stove brands, and think I have decided on a soapstone stove by Hearthstone or Woodstock. I'll probably have it installed professionally, but neither the installer nor the local Hearthstone dealer sound particularly sure about recommending a stove size.

My primary purpose for the stove is a backup heat source for my 3900 sq ft house, presently heated only by natural gas, in an earthquake-prone area (alaska). If we lose our gas in the winter, we're screwed unless we have backup heat. Of course, I also hope to use the stove for supplemental heat, since my wood is free. The house is three stories.

My tentative plan is to put the stove in next to the return air plenum, on the second floor, so I can manually run the furnace fan to distribute heat thru the house via the ductwork. That room is only 350 sq ft. I don't want to undersized the stove and be unable to heat much of the house in a pinch. On the other hand, I don't want to oversize it and be cooked out of that room if I just want a nice fire some evenings.

I'm currently toying with either a Woodstock Keystone (45,000 btus) or a Hearthstone Heritage (55,000) or Homestead (50,000). Do these seem like a reasonable compromise? If I went by the calculators for my whole house, I'd be looking at MUCH larger stoves.

Thanks for any help or advice here!

 

[siddfynch]

Forgot to say what was funky about the house. From the stove room, an open hallway extends north to three small rooms, about 400 sq ft total. Pretty standard.

From the SW corner of the stove room, however, the corner opens out into the kitchen, dining room, and upstairs staircase. There's no door, so the heat would overflow pretty freely to these areas. The west wall of the stove room, meanwhile, is a 4' pony wall that open out to a 30 x 30 room with about a 30' cathedral ceiling. I'll immediately lose a lot of heat from the stove room into this room.

Altogether, that's about 1600-2000 sq ft that opens quickly off the 350 sq ft stove room, with no doors.

So how do I factor that into my stove size?

 

[HollowHill]

From the size of your house, I'd go Progress Hybrid or Equinox. Soapstone heat is not as intense as cast iron or steel heat, so I wouldn't worry so much about overheating the room. My Progress is in a room that is around 250 sq ft, IIRC, with 2 small doors to other rooms, and doesn't overwhelm us. I'm heating 2400 sq ft of very drafty old house. Have you given Woodstock a call? They can give you the best advice as to what would work. They've got a great crew there, all of them very knowledgeable and helpful. One of our members has a Progress in a large house in Canada on a lake - Rideau - you might want to search out her posts as she gives very detailed info on how it is working out for her.

 

[Waulie]

The three you mention are definitely too small. I'm biased towards Woodstock, but I think the Progress would be a great size for you. The Equinox (or maybe the Mainsfield) would work too, but the verstaility of the Progress allowing lower, longer burning fires is a big advantage if you're worried about getting overheated. That said, with that size house I'm not too concerned about you getting overheated.

 

[siddfynch]

From the size of your house, I'd go Progress Hybrid or Equinox. Soapstone heat is not as intense as cast iron or steel heat, so I wouldn't worry so much about overheating the room. My Progress is in a room that is around 250 sq ft, IIRC, with 2 small doors to other rooms, and doesn't overwhelm us. I'm heating 2400 sq ft of very drafty old house. Have you given Woodstock a call? They can give you the best advice as to what would work. They've got a great crew there, all of them very knowledgeable and helpful. One of our members has a Progress in a large house in Canada on a lake - Rideau - you might want to search out her posts as she gives very detailed info on how it is working out for her.

Hollow, do you actively distribute the heat from your Progress through the ductwork, or is just passive diffusion thru open doors?

I ask because I'm not yet certain that I'll be actively able to distribute thru my ductwork (my furnace control board will need retrofitting to run the fan manually).

New

The three you mention are definitely too small. I'm biased towards Woodstock, but I think the Progress would be a great size for you. The Equinox (or maybe the Mainsfield) would work too, but the verstaility of the Progress allowing lower, longer burning fires is a big advantage if you're worried about getting overheated. That said, with that size house I'm not too concerned about you getting overheated.​

Waulie, would you still not be concerned about getting overheated if my goal were to just supplement (non emergency) and not heat the whole house via the duct system?

 

[begreen]

I'm not following the logic here. If the big room is going tp be the area needing the most heat then that is the best area to locate the stove. It won't heat 3900 sq ft unless the house is very well insulated, but it will help. Two stoves or a wood furnace would do a better job.

Note codeequires the stove to be no closer than 10 ft to the return duct grille.

 

[siddfynch]

I'm not following the logic here. If the big room is going tp be the area needing the most heat then that is the best area to locate the stove. It won't heat 3900 sq ft unless the house is very well insulated, but it will help. Two stoves or a wood furnace would do a better job.

Note codeequires the stove to be no closer than 10 ft to the return duct grille.

The logic for placing the stove in the smaller room is as follows:

When the furnace fan is circulating air thru the ducts, it will be better to have the stove near the return air plenum, which is in the smaller room.

When the furnace fan is not running, my belief is the air will diffuse to the rest of the house better if the heat source is in the small room than in the large one. The small room is connected better to the rest of the house; the large room is more of an endpoint. Additionally, the large room has a huge, high ceiling that I assume will trap a lot of heat even after installing a fan. The small room has only an 8' ceiling, so I'm guessing more of the heat will diffuse laterally to the other rooms.

Does that logic seem reasonable?

 

[Ashful]

Code aside, you can only count on your furnace ducts to move warm air from the stove room to the rest of your house if two conditions hold true:

1. the power does not go out, and
2. all of your ductwork is run thru heated space.

If your ductwork is run thru cold basement or attic space, or if your air handler itself is in a cold space, your ducted losses will gobble up what heat the stove produces. It has been tried by many here, but I've only seen it successful in the case where the air handler and all ductwork was kept inside the heated space.

 

[mfglickman]

Code aside, you can only count on your furnace ducts to move warm air from the stove room to the rest of your house if two conditions hold true:

1. the power does not go out, and
2. all of your ductwork is run thru heated space.

If your ductwork is run thru cold basement or attic space, or if your air handler itself is in a cold space, your ducted losses will gobble up what heat the stove produces. It has been tried by many here, but I've only seen it successful in the case where the air handler and all ductwork was kept inside the heated space.

This. Even after having about half of our ducts covered with spray foam or pink fluff in the attic and crawlspaces, the warm air still does not circulate with the blower fan - it cools off inside the ducts. I've thought of experimenting by warming the ducts with the oil furnace then switching to the fan, but if your gas is out that's not an option.

Do you need to cover more space than what you described? Is the stove on the bottom, middle or upper floor?

You're gonna need a big stove....or maybe 2 stoves....IMO.

 

[Pallet Pete]

ducts do not move air effectively as you would hope. Cold air settles ( Cold air returns ) they will pull a very small amount of warm air in but not much. By the time it gets back to the rest of the house it will have cooled off. I think you would be very surprised by how well a room will heat up with the fan to pull air up not down. Cold air settles which means that if you suck hot air up the cold is moving naturally down and getting heated. After all a wood stove is a radiant heater and works very well. I would most certainly put it in the room with high ceilings to get the most out of your heat.

Pete

 

[siddfynch]

Joful, this is a good point, but luckily I am on a slab and there is no attic, so all ductwork is within the heated house space. We had a similar slab/no attic house awhile back and discovered - happily - that when we upgraded our furnace to one with a fan that ran continuously, the air from the wood stove was piped through the house beautifully. That's what's given us the idea for this one. (That house was 1700 ft sq, so the comparison is not perfect).

PalletPete, I'm afraid you've lost me, but I'm definitely interested in why you'd recommend the big room. My concern there is that this big room is off to the side enough that it'll be the worse choice for passive diffusion to other parts of the house. It has three walls (and a roof) to the outside, whereas the small room has only one outside wall and is beneath the partial 3rd floor.

Secondly, my concern is that this worse location for lateral heat diffusion to the rest of the house will be will be further aggravated by high ceilings in the big room that allow heat to move upwards (staying trapped in the room).

 

[Pallet Pete]

Joful, this is a good point, but luckily I am on a slab and there is no attic, so all ductwork is within the heated house space. We had a similar slab/no attic house awhile back and discovered - happily - that when we upgraded our furnace to one with a fan that ran continuously, the air from the wood stove was piped through the house beautifully. That's what's given us the idea for this one. (That house was 1700 ft sq, so the comparison is not perfect).

PalletPete, I'm afraid you've lost me, but I'm definitely interested in why you'd recommend the big room. My concern there is that this big room is off to the side enough that it'll be the worse choice for passive diffusion to other parts of the house. It has three walls (and a roof) to the outside, whereas the small room has only one outside wall and is beneath the partial 3rd floor.

Secondly, my concern is that this worse location for lateral heat diffusion to the rest of the house will be will be further aggravated by high ceilings in the big room that allow heat to move upwards (staying trapped in the room).

Sid wood stoves work by being radiant heat therefore putting them in a small room defats the way they heat. If you put it in a room with a high ceiling but have a ceiling fan then the heat will not be trapped. Turn the fan so that it pulls air up and it will push heat up and the cold air down the walls and warm it up very well. The heat will go down the walls and into any surrounding hall ways moving through the house. As I said before the return air ducts will do virtually nothing because cold air settles that is why they are COLD air returns they will suck cold air in and any warm air will lose its heat as it gets diluted by the cold air from other rooms. Radiant heat works best buy heating up the objects around it at a steady pace and creating a truly warm environment. Forced air is just that it blows heat out in spurts warming a space for a few minutes until the cold walls and objects chill it again. I will tell you right now if you install that in a small room and rely on vents you will be cold ! By putting it in a large space you will heat up a lot more space and maybe a good portion of the house. There is no way you will heat 3900 square ft with one stove maybe one on each end of the house. If I where you I would forget the stove idea and look into an add on furnace that can hook up in the basement and blow through the vents like a gas furnace to heat that kind of space well. It would still be a furnace but wood fired and wood furnaces can heat much better than gas because it puts out an even steady heat. It would be something along these lines.

http://www.menards.com/main/heating...wood-burning-furnace-4000-sq-ft/p-1846272.htm

 

[rijim]

You're in Alaska so you see some serious low temps; how well insulated and how drafty is the house? I have no idea how the return ductwork plan will work but during a power outage you still need a solution. My initial thought is no matter what you do the heat is going to move to that 30' ceiling area and up the staircase. Is there any options to locate on the lower level, if yes, what does that floor look like?

 

[HollowHill]

Hollow, do you actively distribute the heat from your Progress through the ductwork, or is just passive diffusion thru open doors?

I ask because I'm not yet certain that I'll be actively able to distribute thru my ductwork (my furnace control board will need retrofitting to run the fan manually).


Waulie, would you still not be concerned about getting overheated if my goal were to just supplement (non emergency) and not heat the whole house via the duct system?

No, I do not distribute thru a duct system, just aim a small desktop fan (on the floor) blowing INTO the stove room from the room across the hall from the stove room. This has been surprisingly effective at moving the heat around.

 

[siddfynch]

"Note codeequires the stove to be no closer than 10 ft to the return duct grille."

I've researched this with contractors and the local govt, can't find anything more. What's the rationale behind the 10-ft setback?

 

[siddfynch]

Just to follow up with everyone who weighed in here, we went with the Progress Hybrid, with the install to be in the large room (not the one with return air ducting). We'll vent it out a new liner in the existing fireplace.

Many thanks for the input on here. Also, for the "resources" section, which is helping me to build my hearth pad.

 

[rideau]

Welcome, and enjoy the Progress Hybrid. Let us know how you fare, as we are all learning. And feel free to ask questions...we'll all chime in.

 

[rijim]

Hear all good comments on that stove and the manufacturers support; look forward to how this works out for you.