Outside Air Induction?

[user 122190]

Looks like there is a manufactures kit to hook up to my stove air intake. Seems like a natural thing to do. Rather then draw air into the home thru the nooks and cracks, draw most of it via an inlet in the wall connected to the stove via a flexible hose.

Anybody do this and can comment on any felt difference?

 

[Del_]

To be a healthy house it should already have more than enough air exchange.

 

[Franny K]

I have not done it. That is pretty much how all of the pellet stoves seem to work, they draw air in and push exhaust out one tube or pipe inside another. Might be called direct vent. Some propane/natural gas do similar.

One advantage would seem to be with keeping the humidity up. a wood stove can make beams and floor joists shrink this should be lessened if cold air is not being forced in, as it heats up the relative humidity goes down. I have even seen fireplaces with about a firebrick missing for similar outside air. It has been a while since I saw such and it was most likely on a chimney on an outside wall.

If your chimney was large enough a small pipe for the intake air going up to fresh air would be better, cleaner installation and pre heated air.

One would think it would be harder to draw air through a pipe or tube so it might not be usable in the warmer parts of heating season.

 

[user 122190]

I was reading that the cold air is more dense and would increase the burn.

When the stove is in a rage the inlet sucking sound is impressive. It would seem that drawing air thru the nooks and crannies is counter productive to heating the space. The idea is to reduce the draw from the walls that cools the warming air, and rather pull air directly into the stove via an inlet hose.

 

[jjensen]

I've recently Added an outside air kit on an inefficient ambient style fireplace w/glass doors (unsealed) . I've found that the outdoor air exchange works best for increasing efficiency-doors closed, after the FP is hot.

 

[kodiak]

You might want to consider a whole house air exchanger connected to your forced air furnace. This *should* provide the needed make up air going up the flue but in a controlled and efficient manner.

 

[Franny K]

I was reading that the cold air is more dense and would increase the burn.

Interesting line of thought. For the purposes of the situation at hand all the air would be at equal barometric pressure. Most folks run their stoves mostly closed on the air intake and if the result was a bit different setting on that to compensate. The end temperature of the reaction is the initial temperature of the reactants plus the energy derived from the chemical reaction. That is a reason for the pre heated intake on the ultra efficient furnaces, at least in part.

 

[user 122190]

Looks like the best is to call the company and see what they say.

 

[Sandhill Crane]

We have used an outside air source from the beginning, so can not comment on a difference.
I cleaned the chimney yesterday. Note the flue pipe is 90* and T's into straight flue with clean out cap on bottom. When I pulled the clean out cap there seemed considerable draw up the chimney without there being an outside air source, although there is an outside air source on the stove which it may still be drawing through. I had to modify the adapter kit when we changed stove models due to height difference, but it worked out well. Matches often blow out when lighting stove due to draft, so I'd say it is working good. The house is well sealed. Last photo: wall to right is an exterior wall from which the stoves intake pipe originates running behind the tile wall behind the stove, which is a false wall up to the hearth. Total run is 4" x 5'.

 

[user 122190]

Thanks SCrane. My cabin is not well sealed, but probably about average. Your set up is what I was considering moving towards.

I did my search and my read, and it looks like this Cold Air Induction is for well above average sealed homes. For homes sealed "normally" this CAI is of no real benefit.

https://www.woodheat.org/the-outdoor-air-myth-exposed.html

 

[Del_]

Thanks SCrane. My cabin is not well sealed, but probably about average. Your set up is what I was considering moving towards.

I did my search and my read, and it looks like this Cold Air Induction is for well above average sealed homes. For homes sealed "normally" this CAI is of no real benefit.

https://www.woodheat.org/the-outdoor-air-myth-exposed.html

I'm glad that you read about the myth. Woodheat.org is a great source for info.

 

[hedge hog]

In new construction it is a must or a code and can vary from state to state
New homes are very tight
There theory is that you could burn up all oxygen in the home and there are more than that but that one sticks with me
Gas furnace,gas fireplace,wood fireplace,pellet stoves and even electric furnaces all have fresh air hook ups

And I’m waiting to see when they try rig it up to a gas range
My insurance made me go with a pellet stove in my shop and it had to be installed per manufacturers specs and glad I did because of flammable fumes that I might using
But most people never hook these up
In fact I just had new furnace in stalled and they didn’t hook it up to the outside air.

Sent from my iPhone using Tapatalk

 

[Del_]

There theory is that you could burn up all oxygen in the home and there are more than that but that one sticks with me

Impossible.

The oxygen that feeds the fire comes out of the air that goes up the chimney. It does not circulate in the room depleted of oxygen.

 

[hedge hog]

Impossible.

The oxygen that feeds the fire comes out of the air that goes up the chimney. It does not circulate in the room depleted of oxygen.

Like i said it’s their theory in a air tight home



Sent from my iPhone using Tapatalk

 

[Del_]

Like i said it’s their theory in a air tight home



Sent from my iPhone using Tapatalk

Evidently 'they' don't understand how a wood stove works.

There is a lot of that going around.

 

[hedge hog]

I have argued with several State codes
Colorado is the worst



Sent from my iPhone using Tapatalk

 

[ericm979]

A fire would still burn at oxygen levels that would render the occupants unconcious. People who die in wildfires sometimes die from lack of oxygen instead of being burnt. But the house would have to be incredibly tightly sealed for it to be a problem.

Normally the reason for using outside air is to keep the house warmer. If the stove's sucking air from the heated living space that air gets made up by cold air leaking through the walls, windows etc. This is why some fireplaces can make a house colder when in use- lots of draft sucking in cold outside air.

 

[ChoppyChoppy]

Even with an outdoor air kit I had to add some leaks in my house, as it was too tight.
In the hallway I have the top plate in one of the stud bays filled with 2" pipes that go up above the installation and are able to draw air from the attic.

Before this, if the bathroom fan was running it was hard to close the front door, or when opened, it'd about fly open. When the stove was put in, it'd pull smoke from it.
Now it's fine other than if the draft is low and there are both bath fans going and the cook stove vent. I just crack a window open then.

 

[Del_]

Even with an outdoor air kit I had to add some leaks in my house, as it was too tight.
In the hallway I have the top plate in one of the stud bays filled with 2" pipes that go up above the installation and are able to draw air from the attic.

Before this, if the bathroom fan was running it was hard to close the front door, or when opened, it'd about fly open. When the stove was put in, it'd pull smoke from it.
Now it's fine other than if the draft is low and there are both bath fans going and the cook stove vent. I just crack a window open then.

If your house is so tight that you can't run a wood stove then you don't have enough hourly air exchange and your indoor air quality is likely not good.

Are familiar with the fact that houses act like chimneys?

I'm not sure that your vent pipes going into the attic are wise.

 

[ChoppyChoppy]

If your house is so tight that you can't run a wood stove then you don't have enough hourly air exchange and your indoor air quality is likely not good.

Are familiar with the fact that houses act like chimneys?

I'm not sure that your vent pipes going into the attic are wise.

I could run a stove, just the stove was an easier air intake than any leaks.

It is SOP in this area if an HRV unit isn't installed. When something in the house is drawing air, like the bathroom fan, air is drawn in from the attic, which is open to the outside. Set it up this way about 10 years ago.
Normally stuff is designed to deal with the cold, as summers generally don't get much higher than the 70s.

Air Exchange is fine, it's one of the few things that have to get tested to get a certificate of occupancy.