Does fresh air intake for stove make much difference? (Plus additional queries) :)

[Northof49th]

I suppose the question could depend on the application. I am required to have one in my area. The stove isn't picked out yet (most likely going with a BK), and will be placed in the basement. Although I'm not sure if I need to have venting directly into my wood stove, does it benefit if I choose to do that? And should the pipe be insulated as temps can get really cold outside? Just wondering if anyone has any before and after experience with the performance of the stove. Thank you.

 

[Northof49th]

Also, would you add something to the vent to control the amount of air being drawn in?

 

[KDubU]

I have never vented a stove over the multiple ones I have owned and operated. Instead I crack a window and this helps with the draft.

 

[kborndale]

If you have a very tight house with no air leaks then yes an OAK makes a big difference. As for the chimney, yes, insulate it for safety and performance. Especially if it is an external chimney.

 

[EbS-P]

The out side air intake can never be higher than the stove so all/most basements installs do not have them.

 

[Das Jugghead]

I suppose the question could depend on the application. I am required to have one in my area. The stove isn't picked out yet (most likely going with a BK), and will be placed in the basement. Although I'm not sure if I need to have venting directly into my wood stove, does it benefit if I choose to do that? And should the pipe be insulated as temps can get really cold outside? Just wondering if anyone has any before and after experience with the performance of the stove. Thank you.

Also, would you add something to the vent to control the amount of air being drawn in?

Opinions, experiences, and individual scenarios vary. I installed a fresh air intake for my stove the second season we had it and it made a tremendous difference. Prior to installation you could feel cold air migrating across the floor toward the woodstove. Not a breeze but you could definitely feel the cold air. If a woodstove is drawing combustion air from inside the building envelope then efficiency is impacted. That air being consumed by the stove has to be made up and has to come from somewhere. That "somewhere" is from outside the building.

I insulated the intake simply for the purposes of preventing condensation. My woodstove sat in a fireplace and I used the ash dump to route the intake. In terms of controlling the incoming air from outside I cut the ash cleanout door to create a flap that wasn't open that far. My flue was 28' and as such it drafted rather strong all the time. I installed a flue damper to help slow down the draft in addition to the intake damper that was already on the stove.


Here is a write-up of my fresh air intake build: https://www.hearth.com/talk/threads...outside-air-intake-build.182865/#post-2455905

 

[begreen]

It's a commonly asked question. Here are a couple of articles from the Sweep's library that may be helpful.

Sweep's Library - Why burn outside air?

Should I burn outside combustion air in my stove or fireplace?

hearth.com

Sweep's Library - Outside Air: A Conflicting Opinion?

Is there some kind of disagreement about outside combustion air?

hearth.com

As noted, basement installs present a problem. The intake must be lower than the firebox. If this is a daylight basement and the air duct can be run along the floor to outside then it may be possible to direct connect to the stove. Otherwise, providing an air break, a gap between the stove OAK connector and the outside air duct will work. In that case, adding a valve for when the stove is not in use will help stop unwanted cold air infiltration. Some stoves have this air gap built-in to prevent reverse draft out of the OAK.

 

[mpaul]

I had an OAK installed at the time of the initial installation of my unit. The installers put the OAK about 10 - 15 feet above the stove where the chase initially exits the house. I’ve only run the stove in this manner and have not seen any issues whatsoever.

Why is it imperative for the OAK to be installed below the stove?

 

[begreen]

I had an OAK installed at the time of the initial installation of my unit. The installers put the OAK about 10 - 15 feet above the stove where the chase initially exits the house. I’ve only run the stove in this manner and have not seen any issues whatsoever.

Why is it imperative for the OAK to be installed below the stove?

What stove make model is this for?

The OAK needs to be below the firebox in order to prevent reverse drafting where the chimney draft becomes marginal, draft reverses, and the OAK acts as the chimney. It may only happen once, but that once can start a house fire.

 

[mpaul]

What stove make model is this for?

The OAK needs to be below the firebox in order to prevent reverse drafting where the chimney draft becomes marginal, draft reverses, and the OAK acts as the chimney. It may only happen once, but that once can start a house fire.

thanks begreen. I have a fireplace xtrordinair 42 Apex.

 

[Northof49th]

From what I've read, whether a house is tightly sealed or not, an OAK is beneficial. I have to have one installed regardless, and since I'm most likely going with a BK and plan on burning it on low to medium much of the time, I'm assuming I won't need it vented directly to stove. (I can always add it after if needed).

 

[begreen]

thanks begreen. I have a fireplace xtrordinair 42 Apex.

This is what the Apex 42 installation manual says:

• Determine a location for the intake hood.
  • -- Hood must be positioned so it does not become blocked by snow or debris.
  • -- Intake air may be drawn from a ventilated crawl space (check with local jurisdiction for
    requirements in your area).
  • -- Do not draw air from an enclosed space ( such as a garage or unventilated crawl space).
  • -- Certain localities may require the air intake termination to be located at a point lower than the
    firebox opening. Consult your local jurisdiction for details.

 

[mpaul]

This is what the Apex 42 installation manual says:

• Determine a location for the intake hood.
  • -- Hood must be positioned so it does not become blocked by snow or debris.
  • -- Intake air may be drawn from a ventilated crawl space (check with local jurisdiction for
    requirements in your area).
  • -- Do not draw air from an enclosed space ( such as a garage or unventilated crawl space).
  • -- Certain localities may require the air intake termination to be located at a point lower than the
    firebox opening. Consult your local jurisdiction for details.

Thank you for looking this up for me! That last bullet point is the one in question. I’ll give my installation company a call this week. I’ve had no issues in the 4 years of burning 4+ cords/year. But to your point in only takes one time.

 

[Poindexter]

I think it depends on the house you are in. In our old place (1980 build) it was beneficial over all to 'the house' to draw conditioned air into the woodstove and use the stove as a ventilation device. In the new apartment with an HRV, there is no doubt we would use an outside air kit for a woodstove.

 

[Prometeo]

i did it like this,
the tube is not 100 percent sealed,
deliberately to get even a little air from the room, but I still think it's very important and necessary OAK,
in this way you are sure if the house today or tomorrow will be tight the stove will never be able to bring your room into depression,
and therefore you have no co risk

 

[Northof49th]

i did it like this,
the tube is not 100 percent sealed,
deliberately to get even a little air from the room, but I still think it's very important and necessary OAK,
in this way you are sure if the house today or tomorrow will be tight the stove will never be able to bring your room into depression,
and therefore you have no co risk

View attachment 314633

I'm assuming that's a valve at the bottom to shut the air off if needed. And if you're reloading the stove, is it necessary to close the valve?

 

[Prometeo]

I'm assuming that's a valve at the bottom to shut the air off if needed. And if you're reloading the stove, is it necessary to close the valve?

no, when to reload,
with the door open,
the stove will tend to take air from the door, because it is bigger,
there is no reason to close the valve,
I put it to have an extra adjustment having a very high flue, but otherwise it wouldn't be necessary

 

[ABMax24]

I prefer to have a vent into the room and the stove use room air for combustion.

The benefit is the stove helps remove stale air from the house and replace it with fresh. Most modern homes use an HRV or exhaust vent to do this. The stove does this for free. I've also got low concentrations of Radon in my house, the wood stove certainly lowers radon levels while operating due to the ventilation it provides.

 

[fvhowler]

I've never used an OAK and can only say the performance of my stove (good draft/very little smoke entering room) tells me I don't need an OAK. I have a relatively new house built with a wood stove location in mind. Maybe I'm missing out on better performance, I don't know.

 

[jimmyjabjames]

The out side air intake can never be higher than the stove so all/most basements installs do not have them.

That's an important piece of information that nobody told me yet. Good to know! We've tightened up our house drastically but the stove is in the basement. Thanks!