outsite air vent in basement?

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jasons

New Member
Hearth Supporter
Sep 4, 2009
2
cross plains
I'm looking to install a wood stove in my basement, but I want to include an outside air intake. The poured cement foundation is about 4 ft high. Will I be able bend the air intake up the foundation and vent it above ground?

I have included a bad drawing to help explain what I mean.
 

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I did something similar and found that if you elevate the outside air above the stove that cold air pushes way to hard into the stove and causes shorter burns along with cooling off the stove. I ended up taking it off.
 
I'd install the stove without it & see how it performs.
You can always add it later if you think you need to...
 
Makes sense: But how would you ever bring in outside air and avoid that cold air pushing itself in (unless you have a walkout)?

Herbster
 
Todd said:
I did something similar and found that if you elevate the outside air above the stove that cold air pushes way to hard into the stove and causes shorter burns along with cooling off the stove. I ended up taking it off.




This will be a small stove just to warm the basement up. The rest of the house will be heated by my furnace.
Maybe I will try it first without the outside air intake. I'm just trying to avoid making the rest of the house cold by sucking in cold air through any gaps.
 
Herbster said:
Makes sense: But how would you ever bring in outside air and avoid that cold air pushing itself in (unless you have a walkout)?

Herbster

Not an expert here, but I imagine someone could put a damper on the air intake if that really was a problem. I would probably pipe it in such a way as to insure the stove could still pull air from the room if necessary - i.e. make sure if the damper on the air intake was closed off too much the stove would not get choked off. It could become rather complex in a hurry. You could simply open a window near the stove a bit and choose your leak so to speak.

In any case, I'd take the advice to run the stove without the outside air first and see just how much of a problem you have before trying to solve it. Older stoves apparently sucked a lot more air than current ones do and thus OAKs may not provide nearly as much benefit in real installs as we expect them to. Or they might.
 
As I see it, with an OAK installed, you should always have a draft up the flue, with OAK air entering the stove (even if not lit), then warming and exiting the flue. In the end, it will depend on how much stack effect and negative relative pressure your basement will experience.

Running it first without the OAK will give you a good idea.
 
jasons said:
Todd said:
I did something similar and found that if you elevate the outside air above the stove that cold air pushes way to hard into the stove and causes shorter burns along with cooling off the stove. I ended up taking it off.

This will be a small stove just to warm the basement up. The rest of the house will be heated by my furnace.
Maybe I will try it first without the outside air intake. I'm just trying to avoid making the rest of the house cold by sucking in cold air through any gaps.

Does the furnace already have an outside air supply? What else is in the basement that will be competing for air with the wood stove? Dryer, gas/oil hw heater, bath fan?
 
stoveguy2esw said:
Marty S said:
Your diagram has elementary flaws and the plan will most likely disappoint.

Read why here on Page 48 where the picture looks like your set up:

http://cmhc-schl.gc.ca/en/co/maho/e...commonspot/security/getfile.cfm&PageID=189905

Aye,
Marty

hi marty long time bro,

check your link , i couldnt get anything but a blank page

I click it. It works. It is a decent paper to download: "A Guide to Residential Wood Heating" from woodheat.org.

Aye,
Marty
 
If it is a dedicated supply meaning that no air can leak into the room, then it should be fine with two caveats. The first caveat is that the stove have the ability to turn the air down enough to counter the pressure. The second is that you should not take the shortest path as the pic shows. Take a longer route all the way down to the floor to create a P trap that can help resist a possible reverse draft situation where the OAK could act as the chimney.

I would put a tight fitting shut-off damper on the OAK.
 
I have the same exact issue. I was down last year due to broke leg, but I am now back at it and preparing for the burn season. Cleaned out chimney/stove - its all ready to go - but I need to install an oak. Same set up as you have. My situation is not that the house is too tight, but too loose - and when I sit on the basement stair - I feel cold air going down the stairs instead of hot air going up. So the oak must be installed.

BUT after reading your replies, I am worried. I was going to have to go 10 ft up my basement wall to get out the band board. I do have 2 sides of my basement exposed above grade level (house tucked into hill) so now I am thinking about going across the basement floor over to an exposed wall, then going up 2 feet and out a window - then back down to grade level on the outside of the house. I will need to build a block off plate to seal off the open window area and I guess a metal plate for the pipe to go thru. It will look ugly, but at least I can remove it all and shut the window in the summer.

Maybe you could do something like that - to stop the cold air dropping in??
 
Well that makes sence but its the only place for the heat to go up too - is the stairwell. And I think all that cold air is getting sucked in thru the cracks on the first floor of the loose log home and going right past my thermostat on its way down the steps to be consumed by the stove. That kicks the furnace on!!! Maybe same issue with jasons house too?? We burn 24/7 but we still keep the furnace on so we dont come home to a cold home.
 
poooooooooooooooooooooooooooooooook said:
jwscarab said:
I have the same exact issue. I was down last year due to broke leg, but I am now back at it and preparing for the burn season. Cleaned out chimney/stove - its all ready to go - but I need to install an oak. Same set up as you have. My situation is not that the house is too tight, but too loose - and when I sit on the basement stair - I feel cold air going down the stairs instead of hot air going up. So the oak must be installed.

BUT after reading your replies, I am worried. I was going to have to go 10 ft up my basement wall to get out the band board. I do have 2 sides of my basement exposed above grade level (house tucked into hill) so now I am thinking about going across the basement floor over to an exposed wall, then going up 2 feet and out a window - then back down to grade level on the outside of the house. I will need to build a block off plate to seal off the open window area and I guess a metal plate for the pipe to go thru. It will look ugly, but at least I can remove it all and shut the window in the summer.

Maybe you could do something like that - to stop the cold air dropping in??
cold air descending is normal part of thermocycle & good sign that the hot air is rising from cellar

Yeah, what he said. I can sit on my stairwell and feel a good rush of cold air going down the step, but I can also feel warm air above. Your stairwell will be you main supply and return with a wood stove in basement. As far as an OAK goes, I had the same setup and ran it up the wall and the cold air really pushed too hard into the stove cooling it prematurely. No matter what I did I couldn't control it, so I took it off. I like the idea of an OAK but if you don't have an ideal setup to hide the ugly pipe I would just leave as is, it won't make that much of a diff.
 
Thanks all!!!! This post was great!! It kept me from running the oak up the wall and cutting the hole in the band board and not liking the results. I do think I will run the oak horizontal across the basement floor 10-12ft then up 2 feet, out the window, and back down 2 feet. My basement is currently unfinished - so its not a huge issue with the ugly pipe. Plus if I dont like it, its disassembled in 10 minutes!!! When spring comes - I'll take it apart and store it away. It will be good to see if if helps a lot upstairs. I'll keep u guys informed soon! Thanks again!!
 
Drifthopper said:
Hey...Marty...i just got a blank page too..???

What gives..??

It is a slow to load pdf file. Be patient and it should download and open.
 
jwscarab said:
Thanks all!!!! This post was great!! It kept me from running the oak up the wall and cutting the hole in the band board and not liking the results. I do think I will run the oak horizontal across the basement floor 10-12ft then up 2 feet, out the window, and back down 2 feet. My basement is currently unfinished - so its not a huge issue with the ugly pipe. Plus if I dont like it, its disassembled in 10 minutes!!! When spring comes - I'll take it apart and store it away. It will be good to see if if helps a lot upstairs. I'll keep u guys informed soon! Thanks again!!

jw, insulating that basement will make a world of difference, probably a lot more than the OAK with regard to fuel consumed and comfort.
 
jwscarab said:
Plus if I dont like it, its disassembled in 10 minutes!!!
That's a good way to test. Still, I would always include a tight fitting damper so the air can be shut off 100%. Mine lacks the damper which I now plan to retrofit which will be difficult since I have a built-in. My chimney draft sucks cold air through the OAK and when my stove isn't lit, I get condensation and frost on the metal and the glass door. The butterfly on the stove is notched out so as not to shut off the air completely. When I burn 24/7 it's not a problem but if we are away for any length of time it is. The wife decreed no more 24/7 burning so it's about to become a greater problem.
 
Sounds like a good idea, I will add the damper. Sorry if I stole the thread from jasons , I sure didnt mean to. its just that he was planning on doing exactly what I was about to do - he actually saved me a ton of work by not doing that install!

I do have the entire basement insulated. I have 2x4 walls up against the concrete walls - and R13 batts rolled down them. The only exopsed concrete is the 6'x6' area directly behind the stove - I didnt want flamables too close to the stove - and that section of the wall will be rocked some day, and it is below grade.

Thanks again all !!!
 
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