Air supply?

[Tom Sestito]

NO not the the band. I need some guidance on fresh air supply.

I'm building an off-grid cabin that will be pretty air-tight. It will be well insulated, and it will be primarily heated by wood, with propane hydronic heated floor as secondary source.

It will be built up north in Canada where it frequently gets to -20/25C in the winter. So that fireplace will be going a lot, and fireplaces need air. I'm not sure how to get it that air.

I've done a little reading on HRV/ERV, and still learning. Anyone been there/done that or industry experts that can point me in the right direction?

- Best practises?
- Low energy consumption (I'll be off grid)
- Am I over thinking this and the air will come from somewhere else?

Cost is a big factor, but I also want good performance (eventual retirement home so want to do it right)

Any feedback would be appreciated! Thanks

 

[PCustoms]

Have you picked a stove yet?

Can you find one with a direct air inlet?

How big of a cabin?

What will make it tight?

Family has a house that is 100% closed cell, probably needs a HRV/ERV but I've never looked into it for them or done a blower.Heat is hydronic radiant floor on 2 levels, with an unheated loft.

My house is retrofit with closed cell in attic and basement, plus all doors/windows have been redone. Door blower was TIGHT, as in diminishing returns to get any more performance. I primarily heat with wood. I can run 1 vent at a time, barely. Any combo of vents drafts the stove into the house. If it wasn't for the dryness of the wood, ide have humidity issues and would have already done a HRV/ERV setup.

Since I can easily push 80F inside (or higher if entertaining), I just open a window next to the stove as needed, not super efficient though.

 

[JeepYJ]

If you’re wanting to heat with wood you’ll need to get something with a sealed combustion chamber with a fresh air intake from the crawlspace or outside.

 

[Tom Sestito]

Have you picked a stove yet?

Can you find one with a direct air inlet?

How big of a cabin?

What will make it tight?

No stove yet.

I could find one with a direct air inlet.

780 sq ft.

I will make it tight by sealing all the air gap around windows, sill joints, etc.

Thanks for the reply

 

[PCustoms]

No stove yet.

I could find one with a direct air inlet.

780 sq ft.

I will make it tight by sealing all the air gap around windows, sill joints, etc.

Thanks for the reply

I added quite a bit after your quote.

What are you doing for insulation in the wall, floor and ceiling?
.
~800sqft is small, that will not take a big stove at all.

 

[engineer2]

A friend had an airtight energy efficient 1200 sqft house before they became popular. The natural gas water heater provided domestic hot water and also heated the house. I think it had conventional AC.
It had a heat exchanger system in the kitchen that would remove indoor air and exchange it with fresh air at about the same temperature. I understand this is a must in a sealed energy efficient home.

 

[Tom Sestito]

I added quite a bit after your quote.

What are you doing for insulation in the wall, floor and ceiling?
.
~800sqft is small, that will not take a big stove at all.

The cabin is on a insulated concrete slab, with 2x6 walls filled with batt insulation, and 2" foam on the outside. The roof will be 12" of foam trying for R60 roof.

It's pretty simple, but has an unheated loft as well.

The intent is to have it pretty well insulation so I have to heat as little as possible.

Opening a window is a good plan

 

[Tom Sestito]

Sounds like I might be overthinking this (this is what I do lol). I didn't know that wood stoves came with outside air intakes - that might just be my simple solution.

 

[PCustoms]

Sounds like I might be overthinking this (this is what I do lol). I didn't know that wood stoves came with outside air intakes - that might just be my simple solution.

You consider a pellet stove at all? Would require power for the auger, but might be more consistent and better at modulation.

When you're looking for a stove, look for ones that are mobile home rated. IIRC they require the air intake.

I never knew they had them either, otherwise I would have bought one. Logically they're more efficient as they're not using your heated air for combustion.

 

[Tom Sestito]

You consider a pellet stove at all? Would require power for the auger, but might be more consistent and better at modulation.

When you're looking for a stove, look for ones that are mobile home rated. IIRC they require the air intake.

I never knew they had them either, otherwise I would have bought one. Logically they're more efficient as they're not using your heated air for combustion.

Yes we thought of pellet stoves but we have 30 acres of bush, with a practically unlimited supply of wood (pine/fir/poplar/birch). It seems a crime to buy pellets when I can walk outside and there is a lifetime supply of wood. Maybe as I age or get tired of processing wood we'll consider one.

 

[LopezBart]

Our stove has and outside air intake and two step combustion; they're Jøtul F45. Plenty of heat. Getting them to run all night on softwood takes some serious stoking and throttling down, but it works.

 

[Dagny]

barrel stove crack a window.

 

[cannuck]

My recently departed friend lived in a 1,000 sq.ft. cabin in the woods in the winter (and a much larger one an hour by float plane North on a remote island in the summer). The winter cabin was modestly insulated and heated with a single sealed fireplace (backed up by electric heat - winter on the grid). I have stayed there many times on winter nights and we could easily get through the night with a few 4" x 24" slices of firewood at bedtime. So, not going to be a difficult thing to do with OP's planned level of insulation and sealing. The draw up the chimney does a fine job of sucking combustion air in from outside. Oh: should have mentioned the winter cabin 80 km. South of Thompson MB, the summer one 150k or so North so -45 nights not at all unusual.

 

[PCustoms]

Yes we thought of pellet stoves but we have 30 acres of bush, with a practically unlimited supply of wood (pine/fir/poplar/birch). It seems a crime to buy pellets when I can walk outside and there is a lifetime supply of wood. Maybe as I age or get tired of processing wood we'll consider one.

Less acreage here but same reason I installed the stove. Intake down a few dying or undesirable trees each year to get firewood. "Free" heat feels the warmest.

Our stove has and outside air intake and two step combustion; they're Jøtul F45. Plenty of heat. Getting them to run all night on softwood takes some serious stoking and throttling down, but it works.

Nice stoves.

Seems the newer ones are more finicky to run overnight. I sort of miss the old stoves where you just stuff them full and choke them down, but these new ones do burn better.

barrel stove crack a window.

See my comments above. This is about as inefficient of a stove as you can get...