getting stoves to coexist on two floors - possible?

[GreenMountain]

This is the general version of a specific question ( https://www.hearth.com/talk/threads/intrepid-defiant-vigilant-mess.164195/ ).

Scenario:

Two story house, upside down with bedrooms below and kitchen/living up. Cold climate.

Desire:

A small stove downstairs for morning heat, to take the edge off. A big workhorse stove upstairs.

Problem:

The envelope is tight enough that air competition is a problem. The small stove downstairs works fine by itself, but when the big stove upstairs is running its air demand, plus the natural stack effect of the house and cold flue, causes the small stove to backdraft if it's not going at full.

Solution?

Would adding an outside air kit to the downstairs stove reliably decouple it from the house when it's depressurized by the upstairs stove?

What if they both have outside combustion air?

Or is this just never going to be satisfactory? (Put a mini-split heat pump downstairs and forget about wood?)

Thanks for any insights/experiences.

 

[Doc C]

If your getting 90% or more of your air from an outside air kit why why would it not almost completely solve your problem?

Only issue I can see is when you open doors on the wood stove. Then you are sucking a lot of air up the chimney and might be a small nuisance to deal with.

One other thought would be to use outside air kits and then put a proximity air intake near the stove on the bottom floor so that when you send a blast of air up a chimney hopefully the make up air is coming in the proximity air intake.

I Have never had to deal with this situation so I’m just trying to think logical and hopefully some other folks can help out as well.

 

[GreenMountain]

Right - thanks - physics and logic tells me this will work. Hadn't thought about an intake, though there's an HRV inlet nearby; doesn't seem to admit enough air to matter.

I'd like to hear from someone who's done it for real before I start cutting holes in the wall though!

 

[electrathon]

Even if you only have one stove physics and logic says you should have an outside air supply. All air going up your chimney is offset by low pressure in your house, sucking in cold air from someplace that the house is leaking. An outside air source will stabilize this issue and likely make your house a little more balanced heat wise.

 

[Tar12]

I would put OAKs on BOTH...I do not see any reason why it would not fix your problem.When I first installed my BK I noticed cold drafts across the floor...these drafts disappeared after I installed a outside air kit...the install was a piece of cake.

 

[GreenMountain]

I would put OAKs on BOTH...

Ideally I'd put them on all three, but they're all first-generation VCs that don't have OAKs available. I'm not quite ready for the $10k bill. I was thinking I'd start with the downstairs stove with the little Englander (Summers Heat Tranquility)+OAK. Then I can rotate out my cracked Defiant.

 

[GreenMountain]

BTW there's a nice article on makeup air here:
http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/how-provide-makeup-air-wood-stove
Limited agreement on solutions, but some good links.

The Englander just went on sale at a ridiculous price ($494 at Ace with the WINTER17 promo code) so I've ordered one. Will report back on how the outside air works out.

 

[GreenMountain]

The OAK solves the backdrafting problem with the new Englander, so I'm back in the heat business.

However, Tar12 is right - you really need outside air on all the stoves. As is, the new stove downstairs runs fine with the door closed. But if the upstairs stove is running, depressurizing the house, the new stove still smokes into the room a bit when the door is open for loading. It's not a dealbreaker, but not ideal.

 

[Tar12]

The OAK solves the backdrafting problem with the new Englander, so I'm back in the heat business.

However, Tar12 is right - you really need outside air on all the stoves. As is, the new stove downstairs runs fine with the door closed. But if the upstairs stove is running, depressurizing the house, the new stove still smokes into the room a bit when the door is open for loading. It's not a dealbreaker, but not ideal.

Glad you are getting it figured out! Any way you can get a OAK to the one upstairs?

 

[GreenMountain]

Nope. The upstairs stoves are first generation VC Defiant & Vigilant. AFAIK no air kits available. I'll have to replace them down the road I guess.

 

[begreen]

Wow, three stoves. What is the sq ftg being heated?

 

[GreenMountain]

About 2400 - no enough to justify three stoves really. (This is Montana and it does get cold though.) That's partly bad planning on the part of the original builders - the same people who put a Defiant and a ton of rock hearth on an overhang with no foundation pier below. But I'm stuck with the layout, and there's no easy way to move the air around.

 

[begreen]

Yes, Bozeman can definitely get chilly. Still, I'd be looking at modern stoves to reduce fuel consumption and I'd also be scratching my head to make it work with 2 stoves.

 

[moresnow]

Likely make a slight difference if you shut the upstairs stoves way down to a low setting before opening up the downstairs unit. Maybe you already are?

 

[GreenMountain]

Likely make a slight difference if you shut the upstairs stoves way down to a low setting before opening up the downstairs unit. Maybe you already are?

I think it does, though I haven't really tested properly. I've just been cracking the window momentarily when I open the door. It's a pretty good stove for loading & forgetting, so not much of a problem really.

 

[GreenMountain]

Still, I'd be looking at modern stoves to reduce fuel consumption and I'd also be scratching my head to make it work with 2 stoves.

For sure. I was thinking of something like a Pacific Neo or BK Chinook. Maybe use one new stove for the workhorse, and leave the Vigilant as a semi-fireplace.

Sadly, I just blew the stove budget on a cello!

 

[begreen]

For sure. I was thinking of something like a Pacific Neo or BK Chinook. Maybe use one new stove for the workhorse, and leave the Vigilant as a semi-fireplace.

Sadly, I just blew the stove budget on a cello!

Well, at least you have creative pleasure for the other 9 months of the year.

 

[defiant3]

Stupid question, but they all have their own separate flue, yes? Like there aren't 2 appliances in the same chimney, right?

 

[GreenMountain]

Yes - that part at least was done right. Anyway the sizes don't match - the Intrepid (now Englander) downstairs is 6", and the Vigilant and Defiant upstairs are on 8".

 

[Rob711]

My original manual for my 1983 intrepid says a OAK was avail, no idea where you could source this. Would love to see a factory one. Good luck