Building a post and beam, 8" staggered stud, dense blown cellulose , 3 layers of 2" polyiso on the roof.
In northern New England so Im trying to make it pretty tight without going too wacky. The energy consultant said that a ERV isnt needed on this build that 2 of these bathroom continous ventalation fans below were what I need:
 http://cgi.ebay.com/Panasonic-Whisp...e846e7

That leads to my question. They also recommended outside air for my small woodstove thats now on an inside wall.
I was thinking of running some 2" PVC in the wall coming out by the stove and to the garage from the stove and having some type removable cap to pop off when burning. (which will be occasional and more for effect.)

Any other ideas on a good way to do that ? Thought maybe a closable vent piped similarly ?

Thanks for any ideas !

Mark

Mark,
A lot of energy efficient builders use exhaust only ventilation strategies so it is proven. The makeup air does have to come from somewhere though.
The problem is not using the small fans, the problem is when you use the larger exhausts in the house. The range fan can be 150-500 cfm, the dryer is 150 cfm etc. You need a source of make-up air for these in a tight house if you have any unsealed combustion appliances in the house. A HRV or ERV helps equalize this difference, even when it not running. Basically it acts as a duct into the house to let in and equalize pressure. You can do the math to decide if it is economical to do. If you are using Passive ventilation near the wood stove, I would want a barometric damper that opens automatically. What you don’t want is to turn on the range fan or the dryer and backdraft the woodstove.

The second thing to consider is that you can’t get a woodstove that burns at a low enough output for a small well insulated house. I figure I need about a 30 degree temp difference between inside and outside before I can fire the woodstove and not have my get too hot. Wood is around 6000 btu’s net per lb for seasoned hardwood. To keep the stove burning efficiently I have to consume at least 1 lb per hour of wood, so anytime I need less than 6000 btu’s per hour I am raising the temp in the house. Sometimes I just open the window a bit. You have the same problem with pellet stoves unless they have a controller that turns them on/off via thermostat.

It is interesting that as we get more and more efficient houses, finding low output heat sources becomes a problem( besides electrical resistance heat of course).
Cheers,
Eric

Great input Eric. The stove is a small 100 year old Glenwood that will be use just occasionally for effect more than to run the house.
Still I need to try to find a way to get that damper to look and fit right into the inside wall in the great room. They look large diameter. 
Stoves about 8-10' from an outside wall but could run something inside the wall to the back of the stove or just install it on the outside wall away from the stove.
Im thinking it will draw from there whenever Im running the stove if needed ? Id cap it off when not burning Im guessing.
Mark

2" pvc likely is way undersized for a wood stove. My stove manufacturer offers an outside vent formula of 550 mm squared for each kW of output over 5kW. (Sorry, it's British. 1kW=3412 btu; a square inch is 645 mm2.) That works out to a 5 inch inlet for my (smallish) 68k btu stove. My manufacturer says no fans. It doesn't have to be near the stove or even in the same room if there is free air flow.

Thats interesting. Never thought of the fact it didnt have to be near the stove but it makes perfect sense I guess.
Great input.

I am unsure I need the full air-flow at 5" to make up for the stove burn. Im trying to keep the build fairly tight but not over the top. While it will be well built,highly insulated, nearly no bridging,and pretty darn tight...Im sure there will be some air availible beyond the duct I put in...and this should assist it nicely.
Mark

If you could put the vent in a nearby closet with an outside wall, you could open it and leave the door ajar for the time the stove is operating.
As Eric notes, the air supply should also be sufficient for times when the range hood and a bathroom exhaust are operating in addition to the stove. Anything that produces carbon monoxide should be treated with respect.