Here's an odd one - in a suburban neighborhood one person constantly is burning wood to heat his home- the problem is the next door neighbor, who gets the smoky draft coming into her home... no big holes on that side of the house, windows closed, exhaust fans off usually, and minimal use of the forced air furnace. Built in early 2000 so not extremely tight, but not too bad either. 6 ACH50. Ducts in crawl and attic with 7% leakage. Vented crawlspace. Vented attic.
HO wants to install an inline or reversed exhaust fan, with a variable flow control, on the opposite side of the house to slightly pressure the house to keep the smoky air out. She has done some easier air sealing measures but it would take a LOT to do it right.
Correct me if I am wrong but isn't supply only considered bad in your area? Even if it isn't, what happens if another neighbor decides to use there stove where it can impact the supply
Personally I would look into an encapsulated crawl and sealing the return ducts real well up in the attic - then I would look more into airsealing the attic - that should help with stack effect pulling that smoke in along with any that might try via the HVAC system. Then you might want to look into an ERV so you can help filter any smoke that makes it to the ventilation
Thanks Sean! The supply only is generally frowned upon here but not so much with an older house like this. The encapsulated crawl has not worked well here because of radon and moisture issues. The sealing measures have been started and I think we'll encourage her to go that route.
Half the house (guestimate) is already under a positive pressure and at the worst, for a ranch, she is dealing with just a couple of pascals of pressure. The vented crawlspace, as Sean mentioned, would be the place I would start since much of the stack effect and wind driven ventilation starts down there.
Then the question becomes, where do you draw the air from for the positive pressure. To avoid just pulling in more smoke, passing that incoming air through a good air filter of some variety wound seem necessary.
Keeping the relative humidity as low as practical and pressurizing a single story home to a "just enough" level wouldn't be much different from a full 2 story home with typical natural leakage. The key is to seal all leakage as much as possible so the volume of fresh air required for pressurization is minimal and to clean up that incoming air.
Hello: I'd start with the simple approach of asking the neighbor to refrain from dampering down the fire so it can burn hotter and cleaner. If they refuse to change habits, I'd ask the local jurisdiction (city or county) if they have any rules about this. After all that, pulling clean air, possibly from a high point on the roof to pressurize the house is something I've done to keep smoke out effectively.
A cleaner burn is a good suggestion. The neighbor has agreed to extend the flue but that hasn't happened yet. No enforcement for this unless we are under a burn ban - which is rare. This is a 2 story house and the air sealing should be the best place to start.
Hi Kent, I think the positive pressure option will need to be the choice as air sealing can get only so good and even if it was outstanding, extremely tight, you would then have to include fresh air. The only advantage to sealing before positive pressure is the lower amount of fresh air required.
I've had to deal with a couple of homes where wood and cigarette smoke were issues and in both cases the sensitivity of the home owner was significant. The slightest trace of smoke and they could detect it.
In Maine they have had to pass local ordinances to control the outside wood boilers. In some neighborhoods, when the air is heavy, the cloud from all of that smoke just settles around everyone's homes.
Good points. Thanks Bud!
Make the building positive. Bring in more air than leaks out and the air you bring in super filter it. Blow out the dirty air, Then super clean the air inside the building. Its what a clean room does.