Opinions on sizing and air supply for basement wood stove

[mossycup]

Our house is an all electric, 1500 sq. ft., 1968 built ranch with a full concrete foundation basement that footprints the main floor in square footage (1500+/-).

The Oslo does a wonderful job on he main floor. We move the heat (cold air towar the stove room) with a single 12" floor fan that works beautifully. My goal this summer is to tear open the soffits and deal with the improper insulation, ice dam, venting issues. We are going install baffles, insulation dams, new soffit material and adequate intake venting. Once this is all done we can blow in more fluffy stuff to bring the attic insulation up to spec. Windows are all very tight and clean single pane with good storms, they can wait for now. Hopefully, the Oslo will consume less wood next winter.

Now to the basement...
Since we have an electric water heater and no furnace there is no residual heat in the basement. We also don't have any ductwork or perforations to the main floor. The only perforations to the basement are for plumbing. The joists have fiberglass batting in place to buffer the cold basement from the main floor. Right now our basement is 45 degrees. This summer I am also going to foam the rim joists and install 2" XPS (with proper fire barrier of course) on the half of the basement that is still bare foundation wall. The rest of the foundation is currently wood studs and fiberglass batts with paneling. I will need to redo most of this as the vapor barrier method is incorrect and I need access to the rim joists anyway.

Considering the basement will be better insulated by fall, I am going to still need an occasional heat supply. The old electric wall heaters are going in the trash...sorry ComEd;-) The basement is really open, with a '70s stylized recreation area on one end and a workshop on the other. The shop is separted by a framed wall and two doors. The only egress windows are in the shop that I am going to tear out and install glass block with vent windows. Besides children having a potential sleep over in the remodeled rec. area, no sleeping quarters will be in the basement.

Now to the old Heatilator in the rec. area...
It is built into a solid masonry structure and chimney that I can chase with a liner. The chimney was not covered, the top of the heatilator is rusted and trashed. I have insulation stuffed everywhere inside it until I retrofit a new wood burner in it's opening. I am going to have to break out the sawzall or a torch to open up the top of the Heatilator for my liner chase.

Now for sizing the unit...
I am only looking to occasionally heat the basement to take the chill out, allow me to paint, work with adhesives, work on projects, etc. I am not trying to suppliment the main floor heating, although it might happen to a degree anyway. I am used to an overnight burn with the Oslo, but I am hoping that the heat loss in the basement would be slower and an occasional warm up would hold for longer periods of time than what the main floor experiences. I would love to find that the insulation helps slow and stall the basement heat loss/cold infiltration at 55 degrees +/-.

I am not set on buying another Jotul, but I'll start with what I'm zeroing in on from their line. I really like the Jotul F118, and it seems like it could cook us out or sustain an overnight burn if needed. I also like the F3CB for it's size, probably not capable of an overnight burn.

For a dedicated stove in a 1500 sq. ft. basement that is well insulated and sealed, is the capability of holding a larger load or an overnight burn even worth considering? I am just looking to control the environment for a weekend or few days at a time. Super cedars are cheap...any ideas would help.

The other concern is air availability for the stove. Since the basement will be very tight, will an OAK or air supply to the basement be needed to prevent starvation or smoky backpuffing?

Sorry for the long read.

 

[jimbom]

Basement transmission heat loss is going to be minimal. Say 5000 Btu/hr for the walls, 1000 Btu/hr for the floor and zero for the ceiling. Then 4,000 Btu/hr for infiltration and safety factor, so 10,000 Btu/hr. Basically any wood stove will keep it warm.

 

[Todd]

I think I'd go bigger you may decide further on down the road that you want those over night burns or want to keep it burning 24/7 in the colder weather.

Outside combustion air can be tricky in a basement. I had to run my OAK up the wall and out the sill plate and had a hard time keeping the cold air from pushing down into the stove instead of the stove taking what it needs. I ended up reducing the inlet from 4" to 3" and installing a goosneck outside the sill plate to help control the cold air.

 

[mossycup]

I think I'd go bigger you may decide further on down the road that you want those over night burns or want to keep it burning 24/7 in the colder weather.

Outside combustion air can be tricky in a basement. I had to run my OAK up the wall and out the sill plate and had a hard time keeping the cold air from pushing down into the stove instead of the stove taking what it needs. I ended up reducing the inlet from 4" to 3" and installing a goosneck outside the sill plate to help control the cold air.

How well did the cold air issue resolve?

How about running PVC through the sill into the garage and making a jog straight up to the attic space above the garage? Taking the calmer air from the attic could make sense. Neg pressures and CO dangers from garage?

Is the goal to just create a free passage near the stove for basement air to equalize so the stove can draw freely, or is it strictly neccesary to connect an OAK directly to the stove?

 

[Todd]

I think I'd go bigger you may decide further on down the road that you want those over night burns or want to keep it burning 24/7 in the colder weather.

Outside combustion air can be tricky in a basement. I had to run my OAK up the wall and out the sill plate and had a hard time keeping the cold air from pushing down into the stove instead of the stove taking what it needs. I ended up reducing the inlet from 4" to 3" and installing a goosneck outside the sill plate to help control the cold air.

How well did the cold air issue resolve?

How about running PVC through the sill into the garage and making a jog straight up to the attic space above the garage? Taking the calmer air from the attic could make sense. Neg pressures and CO dangers from garage?

Is the goal to just create a free passage near the stove for basement air to equalize so the stove can draw freely, or is it strictly neccesary to connect an OAK directly to the stove?

That would be a long run up to the attic but it would probably be better than sucking CO from the garage. The problem would be controlling that cold air from dropping down too fast and pushing into the stove.

I've tried make up air for the basement in the past thinking it would equalize the pressure but it was just like an open window and let too much cold air in. Hooking it up directly to the stove is better in my opinion.

I'd probably try the stove out without the OAK first before you go to all the trouble.

 

[daleeper]

We have a stove in the basement that is tight, running a stove with 6" flue outlet into an 8" chimney, and don't have the OAK, and I don't think we need it. Of course you may find your situation different.

The more time you spend in that basement, the more you will want to run that stove to keep the floor warm. If I let our stove go out for more than a couple of days, my feet will freeze while working down there the next day or so until that floor gets warmed back up. That insulation in the ceiling/floor joists will keep that heat downstairs unless you have the perfect air flow moving it upstairs, so I know it will be possible to overpower the space with a big stove, but I think you will use it more than you realize. Recommending a stove size is tough, but I would want one big enough that it could heat the basement full time, and then build smaller fires rather than one too small to start with.

Are you looking for an insert, or are you wanting a stove that sits out in front of your fireplace?

Edit:
After re-reading your op, I see you are in fact looking at stoves, and I would want a larger stove than what you listed in the first post.