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Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by Ziprich, Jul 24, 2012.
Just put some cheese on the outside wall and let the mice and rats do the work.
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Not to put in an OAK, but when I put the gas fireplace in my basement, I core drilled through 10" concrete foundation and some cinder block rubble, then came inside the house and drilled a matching hole through a cinder block wall. It was surprisingly very easy with a rental drill / core bit. I even had the wife drill the inside hole...so if they didn't line up, I'd know where to put the blame! Brought the drill home, set it up, drilled outside, tore it down, drilled inside, tore down and got it back to the rental store in 2 hours.
As far as adding an OAK, I'm a bit undecided. Every pound of wood 'needs' about 15 pounds of air to burn completely...and it probably 'gets' about 17-20 pounds of air because we usually run our stoves with just a bit extra air..aka 'lean burn' to minimize the smoke output. So figure a 50 pound armload of wood gets about 1000 pounds of air...or around 13,000 cubic feet. That is roughly all the air in a 1,625 square foot house with 8 foot ceilings.
So yes, you have to heat all that incoming air leaking into the house, but you have to heat it at some point anyway. I suspect a stove burning 75 degree room air burns a bit hotter (or burns less wood for the same heat) compared to a stove sucking in 20F outside air.
On the plus side of the OAK - it will help maintain indoor humidity because you aren't flushing dry outside air through the house. It would also help a stove draft in a 'tight' house, or one where many flues or other exhaust fans are competing for air. The OAK may also help localize the 'cold spot' to the stove instead of having cool air filter in at 'hard to heat' spots such as back bedrooms or areas far away from the stove.
Some rough numbers
50 cfm @ 50T (inside/outside)=~70,000btu/day or ~10 lbs wood
I maybe doing a little remodeling soon So much for building it right the first time.
I've been wondering about an OAK as well. I don't like the idea of pulling in cold, outside air through our doors and windows. We have a floor vent near our living room stove that allows air to flow from the unfinished section of our basement but that air has to be replaced with outside air. I didn't consider an OAK because I didn't want to cut a hole in the tile behind our stove. I just learned from another post that the Super 27 has a place to connect an OAK from the bottom. We have an open ceiling in our basement under our living room stove that can vent through our garage or under our porch. Our basement stove would require cutting throught the stone and outside wall behind the stove so I would only be interested in an OAK For our living room stove. I found some diagrams at http://www.chimneysweeponline.com/cpac27.htm. I'm going to take a serious look at this.
I spoke to a guy that owns a stove shop. He told me that he always has problems with oak stoves. He also said its not good to use cold outside air in the fire box. it cools the stove down to much. i dont know what to do. he might be full of it.
Here is how I look at it......
Your Stove has 70°-80° air without an OAK (inside air for combustion). If you use an OAK your stove may pull 10° air (that's a pretty good average for low temps)
So your saying a 60° difference is gonna play havoc on a 1600° flame (or higher!!) ????
Your dealer doesn't want to spend the dough on an OAK.
Your fire wont be "Cold because of a 40°-50° difference" (more likely unless you live in Northern Canada).
The OAK makes sense to me. Feeding the fire with oxygen rich air & not drawing all that flow through wall outlets & cracks sounds logical.
I'm pulling the outside air through the fireplace ash clean out, so it was no big deal to pipe it.
I believe it makes it easier to warm the rooms furthest away from the stove.
I wood agree with fossil... If you didn't have enough air to run your woodburning stove...you couldn't breath!
Guess I would have to disagree...you're lumping everything together as 'air' when there are actually (at least) two different things to consider...oxygen and airflow / pressure.
Indoors or out, oxygen content is basically the same - and yes, if oxygen content dropped to a point the stove had trouble burning, you'd probably have trouble breathing as well.
But considering the stove draft only pulls a fraction of an inch vacuum - and consider a very tightly sealed house - the stove could starve for air, but you'd never notice the drop in air pressure. There are many instances where people have tight houses, odd configurations or many other appliances exhausting air and the stove won't draft correctly until some other form of make-up air is supplied...yet the people are living quite happily in the house.
I don't think a stove could pull enough air to even measure...And if you can...I'd like to see that one. If your stove is starving...it's probably a draft issue.
You measure the draft of a stove with a Magnehelic gauge. Measures in inches of water.....
New construction homes and mobile homes should have an Oak. With them, your draft issue, is loss of fresh air.
I realize you can measure the draft of the stove...but there is no instrument that can measure the effect if any on the house itself.
Actually, there are instruments that can measure virtually anything, if it's important to be measured. This just isn't.
I used to build homes in Minnesota. We had to be careful so as not to seal up a house too tight...even tho we wanted to. There are many reasons so as to not want to seal up your house. A house needs to breath! I since have moved to Oklahoma. I do not build homes any more but do live in a Star energy CERTIFIED home...not the kind that whereas you can steal the certification from someone. They actually pump up your house with a method of pressurization. Now there is enough air movement to measure this... I still do not think there is a method to measure how little a stove can steal (the fire itself) from your house! Yes...I realize that various items can compete for that air...but no capability to be able to measure the miniscule amount that fire is stealing.
I quess the best measure would be if someone put in an oak with a "T" valve so that it could suck inside or outside air. Since this topic has been discussed many times in the past, that person would answer a lot of questions if they noticed a difference when pulling inside or outside air.
Wouldn't really answer any questions at all, except for that unique installation.
What do you think now Ziprich?
Measuring a pressure difference caused by a stove may be difficult, but seeing a difference it draft, caused by a pressure difference in the house(fart fan) is obvious. I think an OAK would solve this.
And I think it's a gimmick. Your stove is not breathing cause your house is too tight! If your house were that tight...I reiterate. You could not breath. Draft or lack of is not due to a house being too tight. How does your furnace breath? It has returns INSIDE the house.
I'm not sure I'm following you. I agree ,my house is to tight(for good draft w/ fart fan running). But we breath fine.? No furnace. I think my draft or lack of is caused by tight house + fart fan and or dryer,it's fine otherwise. Cracked window solves draft + fan problem for me.
Yo dudes! This isn't anything to get your panties in a bunch about. It's been discussed to death in the past, and so far as I can tell, it just all comes down to what you want to do. Your appliance is going to function with an OAK or without an OAK. If you're in a situation where an OAK is required (there are a couple), then it's a moot point. If not, then if the idea of an OAK appeals to you and you're willing to spring for the additional installation complexity/expense (might be minimal, might not be...depends on the situation/configuration) then, by all means, go for it. If you're not interested for any reason, then skip it. Rick
Yes but does it make a "real" difference in your secondary heating bill (gass or electric)? Thats what I want to know. Code is code. But when its optional, I need to know if I should do it from a finacial perspective. I burn wood because its free. If oak makes it more free, guess what, in it goes.
Nobody here can give you any sort of definitive answer to that question. Way too many variables. I'd say that if it's easy, go ahead and put it in. Do your own data collection over a season or two to see whether or not it makes a difference in your heating bills (many of us would love to have your Santa Rosa CA heating bills). Then close it off and try the same. Lots of folks here would probably express interest in the results of such an "experiment", I'm sure, even though they would really only be meaningful in your home's context. Rick
>Do your own data collection over a season or two to see whether or not it makes a difference in your heating bills...
My wife would instantly tell me if things were better or worse .
The problem is since I've started burning I typically use 34 therms ($36.46 ) in the month of December. All of this is for hot water. I have never had to pay for heat except for chain saws, gas, oil, and splitter hydraulic fluid and time. Without wood heat, my gas heating bill would be $150 per month.
Hence for me, the differences may be unmeasureable from a human "feel" perspective. I would just be interested in the financials of on/off operation in extreme conditions (which I definatly don't have).
Btw, I am a test and measurement guy by profession (old HP dude) and would just like to know this type of "nugget" - that is, does oak save money or not. I don't mind doing the work to put one in, if there is any financial incentive.
The only breathing a furnace needs is for the combustion portion. If there was negative pressure in the furnace area, then it also might need an OAK in order to combust correctly. The supply/return system is closed loop and has little to do with internal/external house pressures.
An OAK takes the combustion portion of the fire (stove or furnace) out of the house's internal pressuring by making it an open loop (intake and exhaust) connected to the outside air.
Another benefit of an OAK is that it allows the house's internal humidity to remain higher. This is a plus in dry winter conditions. It's better for your skin and lungs. And it let's one feel a bit more comfortable at lower temps.