Is a fresh air intake required? I'm on slab & the stove is no where near an exterior wall.

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Arby

New Member
Dec 13, 2022
10
Idaho
I may have a dilemma. When I designed my house, I didn't think about a fresh air intake for my wood stove. My focus at the time was to place the stove so it would be centrally located for even heat distribution. Due to this, it is not anywhere near an exterior wall that I could add a vent through.

The back of the stove will be against a solid masonry wall that is only a few inches wider than the stove is. However, that short wall is isolated from any other walls. In other words, I'll be able to walk all around my stove. I can not bring a vent from under the floor being that my floor is a concrete slab on grade.

I'm worried that the inspector won't pass the final inspection now. No one said anything during the plans review. But, the reviewers stamp all plans they review with a statement saying they can't catch everything and that it is the builders responsibility to build to code.

I'm not clear on the code. Maybe I'm worried for nothing. If code requires a vent though, what am I to do??
 
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It depends on state regs. Some states like WA require this for new construction, others don't. The Rockies covers several states. Where is this?
Does the house have an adjustable HRV system? If so, I'm wondering if this could be considered a workaround?
 
It depends on state regs. Some states like WA require this for new construction, others don't. The Rockies covers several states. Where is this?
Does the house have an adjustable HRV system? If so, I'm wondering if this could be considered a workaround?

Thanks for the speedy reply. I'm in Idaho (I edited my profile).

My home will not have the customary HVAC system. So, the plans examiner said I had to have a mechanical fan to bring fresh air into the house (there was no mention of the wood stove though). So, I was planning to install the simplest and least expensive option available.
 
A good HRV is not the cheapest, but it will pay for itself in saved fuel and improves air quality. It preheats the incoming air with heat scavenged from the exhaust air. A good unit is adjustable so that a steady positive pressure is kept in the room or house.

Check with the Idaho state inspecting authority to see what is required for outside air.
 
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That's for fireplaces. I'm not seeing a section for wood stoves.
 
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That's for fireplaces. I'm not seeing a section for wood stoves.

A client of my wife sells and installs wood stoves in a different, and typically, far more stringent county in Idaho. He told her that he just installs as per the manufacturers recommendations. If they call for outside air, he adds it. If they don't call for it, he doesn't add it.

So far, I've have only looked at the manual of one modern stove that I like. And it calls for outside air. Are there any modern wood stoves that don't call for outside air?
 
So far, I've have only looked at the manual of one modern stove that I like. And it calls for outside air. Are there any modern wood stoves that don't call for outside air?
I can't recall seeing a manual requiring an OAK except for mobile home installations. What stove is this?
 
Section R1006.2 says air intake "shall not be located at an elevation above the firebox". I assume you could go up, across, the down to below the firebox on an exterior wall. Of course this would add resistance to the intake, but in some cases (like my set up) would be a good thing.
 
I can't recall seeing a manual requiring an OAK except for mobile home installations. What stove is this?

JØTUL F 305 R B

Section R1006.2 says air intake "shall not be located at an elevation above the firebox". I assume you could go up, across, the down to below the firebox on an exterior wall. Of course this would add resistance to the intake, but in some cases (like my set up) would be a good thing.

Thanks. I had thought of that earlier and looked at what that might entail. It would be one hell of a mess. :-(
 
I assume the flooring is already put down over the concrete?
 
Sorry to divert a thread, feel free to move my post if it’s rude to segway. But what is the max distance you can run an OaK? In a situation like this where the stove sits central to the house, let’s say you weren’t on a slab, so you could go down through the floor and horizontal along the floor joists and pop out the side of the house just over the stem wall, can you run that 12 feet horizontal for example?
Just curious. I’ve always wondered, cause it’s ideal to have a stove central in the house, but unless you’re on piers or have an unsealed crawl space, what are the options.
 
JØTUL F 305 R B
Thanks. I had thought of that earlier and looked at what that might entail. It would be one hell of a mess. :-(
This model is not for sale in the US. Is this being shipped over from the UK? In that manual, the outside air connection is optional.
If there is a good makeup air system that can be balanced, then I would skip the outside air at this point unless required by the local inspecting authority.
 
You do not NEED a fresh air intake however as @begreen a HRV is a good idea if you can include it.
 
This model is not for sale in the US. Is this being shipped over from the UK? In that manual, the outside air connection is optional.
If there is a good makeup air system that can be balanced, then I would skip the outside air at this point unless required by the local inspecting authority.

I had read something, somewhere, that led me to believe that it was a new stove that would be available in the US in the future. Building this home alone, and being a labor intensive style of construction, I'm at least 2 years out before being able to move in. So...I just assumed it would be available by that point. Maybe not.

At any rate, it was just one of several but similar stoves that I like.

Thanks!

You do not NEED a fresh air intake however as @begreen a HRV is a good idea if you can include it.

Thanks. I will need a fresh air intake by definition of code, or because it's a good idea, or....?

Due to the house not having a HVAC system (will be heated & cooled passively), the building department wants me to put in a HRV. So, yes....I will have an HRV.
 
Plan a location for the HRV or ERV in advance, it's not small and you may want to duct air to different parts of the house depending on the partitions. It will need service access for filter cleaning. Consider a model with Merv13 filtration. This would be important for filtering wildfire smoke. A good one will be super efficient, like 90%. Others will be more like 60-75%. Zehnder, Broan, Panasonic, Mitsubishi are good names in this field. This chart listing will help with brand comparisons.
 
Plan a location for the HRV or ERV in advance, it's not small and you may want to duct air to different parts of the house depending on the partitions. It will need service access for filter cleaning. Consider a model with Merv13 filtration. This would be important for filtering wildfire smoke. A good one will be super efficient, like 90%. Others will be more like 60-75%. Zehnder, Broan, Panasonic, Mitsubishi are good names in this field. This chart listing will help with brand comparisons.

Thanks. That page looks to have a lot of good info.

I have a location for the HRV: In a storage loft above my one and only bathroom. It is the only spot I have for it due to the small size of the home and the nature of the design. I can not run ducting from it around the house, due to the slab on grade floor and an exposed plank and beam ceiling (no attic space). That said, despite the fact there is not quite enough room to stand, there is plenty of space in this storage loft otherwise...

Additionally, the home is completely framed, so there is little I can do now.

So, whether I can find a good one or not, I will have to install a ductless HRV.
 
A duct to the main area can run in the loft, just box it in to protect it.
 
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Thanks. I will need a fresh air intake by definition of code, or because it's a good idea, or....?

Apologies to KDubU. I mistakenly read his post as me needing a fresh air intake. After reading it again, I see that he says I don't need it.

All this said....even if I don't need it, I'm assuming the house would perform better with, instead of the stove pulling air from leaks in the house and causing drafts. Or am I missing something? I guess the HRV would be providing the air though so perhaps drafts will not be that big of a concern. Thoughts?
 
Apologies to KDubU. I mistakenly read his post as me needing a fresh air intake. After reading it again, I see that he says I don't need it.

All this said....even if I don't need it, I'm assuming the house would perform better with, instead of the stove pulling air from leaks in the house and causing drafts. Or am I missing something? I guess the HRV would be providing the air though so perhaps drafts will not be that big of a concern. Thoughts?
Yes, this should work out ok, especially if the system is balanceable like the Panasonic units.
 
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I just found the following on my building departments website:

"Unvented fuel-burning appliances are not allowed."

There's no explanation or anything leading up to it, or following, that gives it context.

What is an "unvented fuel-burning appliance"??
 
What is an "unvented fuel-burning appliance"??
Like an unvented gas heater or stove. Your wood stove is connected to a chimney system. It is vented.
 
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