OAK to My BK?

[North of 60]

I just installed two big stoves in my house. It's a modern home with pretty good sealing except for the 45 recessed lights scattered throughout the house. I decided against an OAK because in my research I came to the conclusion that there is a better chance of no issues by not installing one than installing one. If I think my stoves are starving for air and/or we experience cold drafts in other rooms I might revisit. Until then why bother?
There are just to many variables with pressure differentials between the inside and the outside air.

This is interesting reading..

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

Climate has a big factor in this. Leaky or tight construction Mr Guland seems quite ignorant to mention this. I will shut up now. :zip:

 

[mhrischuk]

There may be circumstances in which a direct outdoor air supply is considered necessary. If it is decided to supply combustion air directly to a firebox, it should be done with full awareness that spillage is still likely if the room becomes seriously depressurized and, for safety reasons, steps should be taken to control temperatures on combustibles adjacent to the air supply duct in case wind effects lead to a flow reversal.

Here he states that yes there may be reason for an OAK but care should be taken since there is a chance the OAK could turn into a temporary chimney if the pressure reverses. If you have pressure reversals, OAK won't fix it. You have a draft issue that could be complicated by your specific home setting, e.g winds, trees, adjacent building and roof lines, chimney location, etc.

I am by no means an expert but reading the entire article, I concluded that,
1) It doesn't say anything that makes me think the writer doesn't know what he is talking about.
2) Just because he doesn't mention climate, it does not invalidate the basic context.

I'm in the... "install when necessary" camp. Why install it if it's not needed?. Wait and see. Burn for a season or two. I'm willing to bet that most installations do not need or have an OAK. That in itself says something.

 

[Hiram Maxim]

I think it's because he tightened the house up in the remodel

I am looking forward to that problem.

No kidding. I would welcome the day when I have to ponder the need for an OAK.

I 2nd that no shortage of a draft in this old house.

It has made a huge difference.....tightening this old house up.

I can stick my hand over the OAK for the furnace/hot water heater and feel air being sucked into the basement when the stove is running and obviously when furnace/hot water heater are not. This tells me that I need an OAK

I'm not debating whether I need one or not, I'm going to Rock one out......without a doubt. :cheese:

When and if I install a 90% or higher efficiency furnace/hot water heater the old OAK will be covered up.

 

[SolarAndWood]

That is quite an accomplishment Hiram, well done.

 

[Hiram Maxim]

That is quite an accomplishment Hiram, well done.

You will be there soon too My Friend!

I appreciate the compliment Solar. Always a work in progress?

 

[SolarAndWood]

Always a work in progress?

Indeed, usually too many works and then there is that work that pays the bills thing. I can tell the difference already even with just the windows, exterior foam and tyvek done. A few inches of foam in the stud bays and I think I will be in much better shape this winter than last.

 

[FireWalker]

I'm glad this subject has come up.

I'm still trying to figure out if I need one.............

Yup, the house is drafty, log construction, passive solar (lots of glass), open plan with the stove centered in plan but I have back spaces that are hard to heat with the stove (HS Equinox). We have a full currently unfinished basement with radiant hydronic oil fired heat throughout most of the 1200sf 1st floor that hardly ever gets used. The entire 1st floor is insulated.

Now one might think with this stove we would have no problem making it too hot............this is not the case, I compete each cold night with massive heat loss thru my south facing glass. I have insulated curtains but they are not by any means airtight. We also have a big problem with maintaining comfortable humidity levels and the basement gets cold.........lower 40's come mid-late winter.

My thinking is the stove gobbles up massive amounts of air which it gets from the 'not very tight nature of log construction' and 'lots of glass'. Some would say I'm a likely candidate for an OAK and the benifits would be:

Less drafts as the stove would no longer create negative air pressure inside my home.
Increased humidity levels as the stove would no longer be pulling cold dry winter air into the house.
Less smoke spillage during low fire level start-ups/fueling.

So, can I draw air from my basement? My basement is by no means airtight......cmu walls with 3 feet of wall above grade, I've got basement windows and the only device I have down there that uses combustion air is a nice relatively new Pierless oil burning boiler.

My thinking is with air being drawn from the basement, might this help move heated air back into the house where my basement access is and also address the benifit issues listed above? Is there a code issue with regard to this proposed setup? Anybody out there doing this?

 

[Hiram Maxim]

Well I finally got the Outside air connection done today.

FYI: Home depot has 25 feet of insulated 4" flex for $24.99 (R-6)

I used 4" PVC through the outside brick wall, and tomorrow I will be doing the Outside "S" trap.

8 feet below the stove I switched to uninsulated 4" and then reduce to 3" for 2 feet before the intake on the stove.

I already notice a slight difference, in that there is less cold air moving across the floor towards the stove.

Time will tell. :cheese:

 

[jeff_t]

So, how's it working out?

 

[Hiram Maxim]

So, how's it working out?

hard to tell with the warmer weather, but the window stays much cleaner, there's no draft across the floor, and it seems like the burn time has increased...more to come