Outside Air vs Room Air

[Coyoterun]

The chimney suction does add, but it's not going to add one to one. Are you considering pressure changes? Yes, more air flows out the chimney, and it causes a decrease in pressure in the basement, which draws more air into the basement. But that same pressure drop is going to decrease the amount of air flowing out of the upper house envelope. So some of that air that is now flowing out the chimney had been flowing out of the attic anyway. It's not a one to one increase in incoming air.
I don't have the math to calculate it, and it's gonna vary wildly anyway depending on temperature and wind conditions, but I'd guess it's more like a 50% or less increase. Maybe 208-210 CFM instead of 200 CFM. Is 8-10 CFM worth cutting another hole in house envelope for a stove that may not be completely sealed to the indoor air?

But put aside where the air is coming from - no matter where the air comes from, it still needs to be warmed up.
With an OAK, it is cooling the stove instead of the basement walls, but the basement walls are warmed by radiant heat from the stove. The stove is heating the same amount of air. Does it take more energy to heat air in the basement as compared to air in the stove?

I do think that OAK's can serve an important function in certain installations. But maybe not in every case.

 

[Karl Hungus]

you guys are dreaming with a leakage rate at 200cfm.
Only a very small very very tight house would see that.
The other thing about measuring leakage in cfm is it has to be related to size of the house to mean much.
200cfm for a 500 sq ft tiny house is good., 200cfm for a 5000 sq ft McMansion is incredible.
Previously someone mentioned a air change rate of .6ACH for air quality. An air change rate that low is Passive House territory.
You will never see that in even above average new construction.

If I had to bet I'd say most new construction is above 2ACH.
on a 2000 sq ft home that equals around 350 cfm.
On your typical old existing construction I'll bet its several times that.

Here is a link with info on air leakage for further education if anyone is so inclined.

http://www.energyvanguard.com/blog/52450/How-Much-Air-Leakage-in-Your-Home-Is-Too-Much

So again, your 1970's 2000 sq ft ranch house is leaking 1500cfm's and your worried about 20cfm's used in the wood stove?
To Quote Hillary "What Difference does it make"

 

[Coyoterun]

Yeah, my house isn't pressurized to 50 pascals very often, but it's still leaking more than 200 CFM during the winter. You made the biggest point of all, an additional 20 cfm just isn't that big of a deal if you're starting at 500-1000 CFM.

 

[electrathon]

So again, your 1970's 2000 sq ft ranch house is leaking 1500cfm's and your worried about 20cfm's used in the wood stove?
To Quote Hillary "What Difference does it make"

So with this rate of "leakage" you are loosing 100% of the air in your house about every ten minutes? There is no way an average home leaks anyplace near all of the heated air every 10 minutes, that is insanity. I would guess that there is a decimal point error or you are assuming that everyone has all of there windows wide open and fans blowing the heat out. I would guess a pole barn is more tight than that.

 

[electrathon]

you guys are dreaming with a leakage rate at 200cfm.

http://www.energyvanguard.com/blog/52450/How-Much-Air-Leakage-in-Your-Home-Is-Too-Much
"

Ok, I get where the insane number came from. THE HUGE FAN CRAMMING AIR INTO THE HOUSE TO FORCE LEAKAGE! From the site: Please don't talk to me about ACHnat ('Natural' Air Changes per Hour). I loathe that measure! This is a totally wrong number if you are looking for air leakage in your house. If you have a huge fan forcing air into your house, use the number, if you close your doors and windows when it is cold the 200 number is far more accurate. 20 CFM us a far larger percentage of air migration when you use natural house pressures.

 

[electrathon]

To Quote Hillary "What Difference does it make"

I missed this earlier, now I am laughing. This was a perfect comparison to Hillary. It makes a ton of difference because the facts used were totally false and misleading!

 

[St. Coemgen]

An appliance specific outside air kit (OAK) is one option. But if you have a tight house, wood stove or not, you may also want to look into a generic air heat exchanger solution for air flow, especially if you have Radon gas issues in your home. Moves in fresh air to the whole living space, while retaining more heat.

For what it is worth, in our tight house, I installed house wide air heat exchangers, not a direct appliance OAK. And it works fine.

 

[madison]

How is that a good point, when the clothes dryer vent is an exhaust, with a flapper? It can't suck much air at all with the flapper installed. Kind of like snorkling... with a piece of duct tape on the snorkel.

Because it leaks along and in addition with the rest of house - unlike duct tape on a snorkle.