I crack a window in the room with my woodstove to provide fresh air locally rather than it being pulled around doors on the other side of the house. This hopefully keeps cold air from leaking in these colder parts of my house. I don't even notice the cold air from my window since my stove keeps that room toasty. But how much should I crack it? Right now I crack it open about 1/4" and the window is 44 inches tall - which equals about 11 sq. inches.
How much to crack a window?
- Thread starter wahoowad
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
- Status
I would open it up about 4" for a very short while while firing up the stove.
Not so much for the air but to nutralize any pressure differences. Then go back to that 1/4"
The key is to notice if it makes a difference, and make adjustments from there.
It could be, that you only need it open to get a good fire going and to establish a decent draft
Not so much for the air but to nutralize any pressure differences. Then go back to that 1/4"
The key is to notice if it makes a difference, and make adjustments from there.
It could be, that you only need it open to get a good fire going and to establish a decent draft
I do open it more at startup to help the draft. I'm talking about once the fire is going. How do I know opening it up 1/4" is good compared to 1/2" or 1" or whatever? I've read somewhere about a woodstove consuming all the air in a room every X hours - that obviously is a rule of thumb as it depends on the size of the room and burn rate, etc. But is there a rul of thumb about consumption rates so I can tell if a 10 sq. inch air supply is adequate, or 15 or 20?
Wow, thought I'd get more responses. I guess it isn't an exact science.
How is this methodology? I look at my primary and secondary air inlets and estimate their cross section. Then I just have that much cross section of window open?
I probably have 5 to 6 sq. inches on my primary and WAG I have 4 sq. inches max for the secondary on the back. Thats about 10 so my 1/4" crack in the window is about right?
How is this methodology? I look at my primary and secondary air inlets and estimate their cross section. Then I just have that much cross section of window open?
I probably have 5 to 6 sq. inches on my primary and WAG I have 4 sq. inches max for the secondary on the back. Thats about 10 so my 1/4" crack in the window is about right?
I am sorry kind of left you hanging Very busy today Correcting a major framing mess up on a job.
Not my job, I was hired in to re-frame the stairs. I could go on again about framers that can'''t read plans and immigration laws.
When all is was said and done, the stair opening was not long enough which effected two sets of stairs.
Back to your situation there is no exact formula, that will determine the air needed for from your window. No one know how much room air is being used and whether the window open does what. I still think you should open it up maybe 2" to start your fire possibly 5 minutes or so then close it down to 1/2 to 1/4". This will be a trial and error approach to see if it helps get you started and helps maintain your draft. I think all forum members exhausted all other possible solutions with the exception of an extension of your flue/ chimney
Here is the formula for every 1000 btus 50 cubic feet of combustion air is needed to support proper combustion. It is so hard to apply it to your situation, with all the variables. I wish I had a better answer. Be back on line again after Bowling 9:30 or so
Not my job, I was hired in to re-frame the stairs. I could go on again about framers that can'''t read plans and immigration laws.
When all is was said and done, the stair opening was not long enough which effected two sets of stairs.
Back to your situation there is no exact formula, that will determine the air needed for from your window. No one know how much room air is being used and whether the window open does what. I still think you should open it up maybe 2" to start your fire possibly 5 minutes or so then close it down to 1/2 to 1/4". This will be a trial and error approach to see if it helps get you started and helps maintain your draft. I think all forum members exhausted all other possible solutions with the exception of an extension of your flue/ chimney
Here is the formula for every 1000 btus 50 cubic feet of combustion air is needed to support proper combustion. It is so hard to apply it to your situation, with all the variables. I wish I had a better answer. Be back on line again after Bowling 9:30 or so
I'll take the following guess - the rate at which the stove will suck in combustion air should be about the rate at which it can send the burned gases out, in order you to not have a pressure differential in the room. So, if you have a opening the flue size in area somewhere in the room, you should get enough combustion air.
I have seen auto vents which stay closed until a pressure differential causes them to open and suck in air from the outside. You might consider installing one of those, then you don't have to deal with the window crack open bit.
Or you can also use the rule of thumb provided by Elk.
I have seen auto vents which stay closed until a pressure differential causes them to open and suck in air from the outside. You might consider installing one of those, then you don't have to deal with the window crack open bit.
Or you can also use the rule of thumb provided by Elk.
a 6 inch stovepipe means I need about 28 sq. inches using the formula for a circle. But what is the 'bottleneck' in air flow - the inlet size of the air supply to the stove or the size of the exhaust? I would think they'd be pretty much the same but I doubt my air supply to the stove has the same cross sectional area as the 6 inch stovepipe.
I'd say the inlet of the stove would define the minimum, the outlet would define the maximum. Remember we are trying to make sure we have air coming in at the same rate as it could possibly be consumed.
- Status
Similar threads
