ASV cs OAK

[tabner]

For people with a super tight home, who aren't able to install an OAK (stove location in the home, basement install, OAK terminate higher than stove, etc), are these Air Supply Ventilator products a viable alternative? Any cons/bad experiences?
I think the main negative is going to be pulling cold air into the home - but theoretically it should pull in the same amount of cold air, as every woodstove installed without an OAK (which is most homes i think). Only difference is rather than that cold air sneaking in around windows and sill plate, it's coming in from one spot, but I would think the CFMs of cold air are the same thing?

Wood stove & Fireplace Air Supply

Condar's air supply ventilator ensures your house is properly ventilated and your fireplace or wood stove operates efficiently.

www.condar.com

 

[moresnow]

Never seen one installed. I have a perfect place to put one however! If I could talk the gent into trying it. Seems like a reasonable idea to try out for some people struggling.

 

[tabner]

Never seen one installed. I have a perfect place to put one however! If I could talk the gent into trying it. Seems like a reasonable idea to try out for some people struggling.

Thanks for the input. I'm curious about it because i have to have an energy audit performed next week, and as part of that they depressurize your house, measure the CFMs, seal every air leak they can find, and then retest. I'm installing a basement woodstove in a month or so, and I am not able to use an OAK (due to basement walls, OAKs terminating higher than stove, etc)

Interesting read at the link below. According to this info, even an air tight home let's in about 1250 CFMs at 50 pascals. google says a typical chimney draft is about 50 pascals. So theoretically even a very air tight home would let in enough make-up air to handle a wood stove.

Technically Speaking: What the Blower Door Test Tells You

So, your local professional has come in and calculated the numbers that reference your home's air leakage. But what do these numbers mean?

www.bpihomeowner.org

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[John Galt]

I can pass along lots of ventilation research I have done over the past couple of years. Hopefully this doesn't sound crass.

I've seen other designs similar to this, basically the same, but more expensive. Cut a hole in the house to let fresh air inside. I can see this as a better option than sucking air through the small cracks throughout the walls since vapor in that cold air can condense, inside the wall once it gets warm. Generally if the house is that leaky, you don't need an OAK and there shouldn't be mold or rot since the walls will dry out in the summer.
This style never made sense to me since someone who spends the money to make a house "air tight" usually has an air exchanger included in the design. I'm currently building and have had to make decisions regarding my air make up. Either build "leaky" and let the air ebb and flow naturally, or build tighter and incorporate a way to exchange the air mechanically.
This sounds really negative, but you can achieve the same thing by sticking a piece of PVC through the wall and shoving some steel wool inside.

 

[tabner]

I can pass along lots of ventilation research I have done over the past couple of years. Hopefully this doesn't sound crass.

I've seen other designs similar to this, basically the same, but more expensive. Cut a hole in the house to let fresh air inside. I can see this as a better option than sucking air through the small cracks throughout the walls since vapor in that cold air can condense, inside the wall once it gets warm. Generally if the house is that leaky, you don't need an OAK and there shouldn't be mold or rot since the walls will dry out in the summer.
This style never made sense to me since someone who spends the money to make a house "air tight" usually has an air exchanger included in the design. I'm currently building and have had to make decisions regarding my air make up. Either build "leaky" and let the air ebb and flow naturally, or build tighter and incorporate a way to exchange the air mechanically.
This sounds really negative, but you can achieve the same thing by sticking a piece of PVC through the wall and shoving some steel wool inside.

Thanks for the info. Side note - I love the screen name.
I would think in your case of new construction you'd go for air tight, and then put in an OAK?
My issue is I cannot run an OAK because of height above stove. So was wondering if the ASV somewhere in the vicinity of the stove, would accomplish the same goal. I'll know after this energy audit how air tight the house really is, but I was just curious up front how effective these ASVs are, and why I don't see a lot written about them on here.
I don't think your comment was negative at all. So you're just saying the ASV should work fine, but no point in spending 100$ when it's basically just a pvc pipe with a screen on it?
(If that's your point then I completely agree. I already thought that. Piece of pvc with a 15$ inline check valve, would do the same thing)

 

[avsmusic1]

I had an energy audit (energize CT) is our last house. It was a 20s house though and was plenty drafty even after they did their work. Is your home new(ish) construction or do you have a specific reason to expect issues?

 

[tabner]

I had an energy audit (energize CT) is our last house. It was a 20s house though and was plenty drafty even after they did their work. Is your home new(ish) construction or do you have a specific reason to expect issues?

Same here, energize CT.
No real reason for concern, it's just I didn't realize they actually seal the house, I thought they just measured. I was just informed today that they seal as much as possible.
House was built in 87, and then has updated double pane windows. I suspect it's pretty air tight.
It was just on my mind because I see a lot of warnings on here about negative pressure in basement stoves, plus I wouldn't be able to do an OAK if I needed to. So I was researching backup plans.
I guess I'll wait and see. If I have problems I'll have to try the ASV, or maybe punch an OAK through the foundation on the above grade side.

 

[Poindexter]

I would wait for your air door test/ pressure test and then see where you are.

My 1980 build is pretty tight with vapor barrier, but "hats" weren't a thing yet. I think I have pulled all the interior window trim in the last ten years, sprayed in the correct expanding foam between window and house framing, and gotten to be not bad at trimming interior windows.

You are correct that your wood stove is going to draw a certain amount of CFM from somewhere, or not run very well. For new builds, I think the sensible thing to do is integrate an OAK right along with the chimney, and not try to feed the stove filtered air from an HRV.

At my place currently most of the air for the stove (upper level) comes under the door sill on the main entry door (lower level). My 1200 sqft upstairs is an oasis, the downstairs with the air for the stove coming under the main entry door, not so much. Thermocline on the stairs for the win.

If you have a sliding patio door, you might ask the pressure testing crew to re-run the test with the sliding door tape closed with packing tape or masking tape. At my place the sliding door is on the upper level leading to the upper level deck. My hunch is if I someday give in to LOML's desire that I spray foam under the lower level entry sill the stove will then draw it's air through the sliding door on the upper level.

 

[John Galt]

The thermocline was amazing to experience in our old house. 38 F in the finished basement, 70 upstairs with the stove, open stairwell. You could stand there with your head warm and your hands freezing.

I agree with Poindexter. Wait for the test, run the stove to see if there is an issue. Basement make up air is more difficult to find if you can't install an OAK. Even with them sealing the low hanging fruit there should be lots of air sneaking into a house built in the 80's. A clothes dryer pulls 200cfm, range hoods are 300-400cfm. If you can run these two at the same without having to crack a window, you should be fine.

We had a huuuuuge range hood in the old house - 1000/1200cfm. We had to be careful not to let the dog in the kitchen for fear of it getting sucked up off the floor. There was never an issue burning the stove with that running on high but if you cracked a window air rushed in hard. The only problem we had was when I was lighting the stove one morning while my wife was cooking and cranked that thing. The stove door was cracked we filled the house with smoke in seconds when it sucked the chimney clean.

 

[jetsam]

Even basement stoves have the option of a decoupled air supply. Put a hole in the wall, run a duct with a hot air trap, and terminate it near the stove (not attached to the stove).

You're basically choosing to let the cold air in the house near the stove rather than dragging it across the house.

 

[tabner]

Even basement stoves have the option of a decoupled air supply. Put a hole in the wall, run a duct with a hot air trap, and terminate it near the stove (not attached to the stove).

You're basically choosing to let the cold air in the house near the stove rather than dragging it across the house.

Thanks for your response. This is exactly what I've been wondering about. Whether an ASV, or ideally something like you're describing, I feel like there should be an option out there. I saw another thread on here where the guy had a stove with a 'decoupled' air supply actually built into the stove design. I feel like a person should be able to make that no problem. Just some 3" vent and an inline check valve (just to minimize air flow when stove is not in use. Not sure what the termination near stove would look like, i suppose it could be just a small vent grill in the wall behind the stove, or you could fabricate some type of bracket/box to the bottom of the stove with a gap and holes to break the connection.
Anyways, thanks for all the input. As others have mentioned, I'm going to see what the air test shows, and then wait to see how the stove runs. if it requires a cracked window to draft properly, I guess I'll revisit this.

 

[DeadTreeBurner]

What's wrong with OAK termination being higher than the woodstove?

 

[tabner]

What's wrong with OAK termination being higher than the woodstove?

It has potential to act as a chimney, if draft reverses, hot flu gases would be going up and out the OAK. Obviously an OAK isn't a chimney, so this would most likely melt and start a fire.

 

[DeadTreeBurner]

It has potential to act as a chimney, if draft reverses, hot flu gases would be going up and out the OAK. Obviously an OAK isn't a chimney, so this would most likely melt and start a fire.

This shouldn't be a problem for a pellet stove though, correct? Pellet stove air flow is driven by a fan, plus at least mine has a directional valve on the air intake - one way air flow only. I plan of locating intake in the rim joist, stove is in the basement. I was going to just draw intake air down the lined chimney, but decided against it.

 

[tabner]

This shouldn't be a problem for a pellet stove though, correct? Pellet stove air flow is driven by a fan, plus at least mine has a directional valve on the air intake - one way air flow only. I plan of locating intake in the rim joist, stove is in the basement. I was going to just draw intake air down the lined chimney, but decided against it.

I'm not sure. What you're saying makes sense, but I don't know anything about pellet. Someone else will have to chime in.

 

[begreen]

This shouldn't be a problem for a pellet stove though, correct? Pellet stove air flow is driven by a fan, plus at least mine has a directional valve on the air intake - one way air flow only. I plan of locating intake in the rim joist, stove is in the basement. I was going to just draw intake air down the lined chimney, but decided against it.

This thread is pertinent to wood-burning stoves. Pellet stove installation questions should be posted in the Pellet forum for a better response.

The Pellet Mill - Pellet and Multifuel Stoves

Wood Pellets and Corn, as well as mixed biomass agri-fuels are becoming popular due to local availability and ease of use. A wide choice of stoves, inserts and central heaters are currently available in this category. This Forum room is for discussion and troubleshooting of these appliances and...

www.hearth.com

 

[DeadTreeBurner]

This thread is pertinent to wood-burning stoves. Pellet stove installation questions should be posted in the Pellet forum for a better response.

The Pellet Mill - Pellet and Multifuel Stoves

Wood Pellets and Corn, as well as mixed biomass agri-fuels are becoming popular due to local availability and ease of use. A wide choice of stoves, inserts and central heaters are currently available in this category. This Forum room is for discussion and troubleshooting of these appliances and...

www.hearth.com

Understood, still good to note that +/- for OAK don't necessarily apply equally across pellet vs wood stoves.

 

[trx250r87]

For people with a super tight home, who aren't able to install an OAK (stove location in the home, basement install, OAK terminate higher than stove, etc), are these Air Supply Ventilator products a viable alternative? Any cons/bad experiences?
I think the main negative is going to be pulling cold air into the home - but theoretically it should pull in the same amount of cold air, as every woodstove installed without an OAK (which is most homes i think). Only difference is rather than that cold air sneaking in around windows and sill plate, it's coming in from one spot, but I would think the CFMs of cold air are the same thing?

Wood stove & Fireplace Air Supply

Condar's air supply ventilator ensures your house is properly ventilated and your fireplace or wood stove operates efficiently.

www.condar.com

Consider installing an ERV or HRV as suggested earlier. I installed an ERV about 3 years ago and noticed a big difference in air quality and my house was nolonger under negative pressure all the time. It's also great knowing I'm not dumping 0 degree air directly into my house.

Eric