Safeguarding house

[edl]

hi all - i am getting garage fumes in the house - there is no central ac outlet in the garage - but the space above the garage is finished - so the subspace between the garage and second floor connects to the rest of the subspace in the house - there are a couple of places where the garage has holes in its ceilings and negative pressure from the house is drawing garage air - small gaps (lack of caulking) around hvac registers in house then acts as a ventruri and pulls some of that subfloor air down into the house as it blows out.

so ok - i will patch these holes in the garage (including nail/screw holes where things have been moved) - caulk the registers in the house - but this has opened my eyes to this issue - what else can I do - no matter what, I don't want my family at risk for fumes in the house

a couple of things occur - I can talk some dry wall down and frame up the space all around the perimiter of the garage where it meets with the rest of the houses subfloor between the first and second floors - in other words, try to make the garage space 100% air tight to the rest of the house - whether practically i can get this done i don't know...but that would be the strategy...

the other obvious (??) thing that occurs is an exhaust fan with leaving the garage door open a crack (found that if i create too much negative pressure elsewhere the same thing happens in reverse - that is the pressure forces air through a soffit and causes sweating on the hvac stuff - yes, i will deal with that as well) - hoping that this would allow a closed circuit there that would vent the garage itself such that the negative pressure there would be more than the house and pull the garage air that way and with the garage door open a crack the draw would be there and not pulling from the house.

Thoughts???

thanks!!!!!! ed

 

[Franz©]

Grab a drier vent and a computer fan, and make up a fan assembly that penetrates the garage wall. Your garage probably already has sufficient leaks that a computer fan won't make the garage a negitive pressure room, but even if the garage does go negitive it will prevent fumes from coming into the rest of the house by drawing air from the house.

 

[PxTx]

Do you have an electric attic fan in your house? What type of heat do you have in the house, forced hot air? I understand the garage does not have either.

 

[edl]

thanks guys - yes, we have 3 attic fans - that is how we discovered the condensation problem - it created negative pressure in the house, and drew in hot air from outside through a porch soffit for a porch roof that apprantly was not framed to block it from the rest of the house - so the hot air met the cold ac stuff and what a water mess that has been

i have separately been looking into exhaust options in the garage - wanted to hook up a little homemade desktop paint booth - i have an hft dust collector - so rather than have the exhaust hook into a trash filter system, i'll have it exhaust out through a 6" laundry vent - the dust collector has ducts running all over the place (each with a blast gate so cfm can stay as high as needed - total cfm is 1600 - i would guess this will create negative pressure in the garage - but can lower this through the blast gates and can crack the garage door so as not to pull air out of the house -- thoughts?? - thanks ED

ps heat in house is forced hot air

 

[kbs2244]

You can get the negitive pressure just from taking a shower with the exhust fan on, or the wife running the smoke exaust over the stove.
You are going in the right direction. Seal everything you can think of and also provide air circulation in the garage.
I would go bigger then a computer fan. It is the right idea, but not big enough. An old style 8 inch kitchen exhaust fan, in the wall oppesite the house, with a small vent near the house should work. Do not put a switch on it. Someone may turn it off and you want it to run all the time.
Exhaust your paint booth with an over the stove type hood.
I am a big fan of air circulation in shops and garages. I have an old family room celing fan going in my garage 24/7/365. Aimed up amd on med speed, it keeps thing from getting stangent and smelly, and rusty.
When I am out ther working it is often helped out by a 20 inch box fan set on med and aimed corner to corner, just to keep things mixed up.