Use an ERV to mitigate odors from garage?

[hmbemis]

My garage is under our bedrooms, and next to a family room.

When I park my 45 year old car there my wife complains there are odors getting in the house -- gas, grease, what have you -- I will admit the odors absolutely get into the house, it does stink... doesn't matter that I like it

I think part of the issue is we have forced air for heat and cooling, the previous owners (or maybe the builders) of the house installed two 10" HVAC outlets in the ceiling of the garage... I have the grills closed, but I assume this still creates positive pressure in the garage, and also negative in the rest of the house which promotes air exchange through the house-to-garage. The intake ducts in the house are also running through a chase, and that chase has a couple of plastic access holes which are not air tight, so I'm sure that there are plenty of paths for the odors to migrate.

I intend to remove the two HVAC outlets and close them off w/ sheet metal, rivets, and pookie. I'm also going to close up the plastic access holes. Hopefully that will help quite a bit, but would an ERV/HRV also help to keep odors in the garage down?

 

[mike93lx]

A garage should never have hvac ducting tied into a house. Closing them off should take care of it. An erv shouldn't do anything if the system isn't drawing air from the space anymore.

 

[acer66]

Not sure about erv but hvac vents in a garage are a big no no.


Edit: Mike beat me to it.

 

[hmbemis]

Yeah, I def. know the HVAC outlets are no good. I was shocked to see them when we first looked at the place, but I'd be lying if I said I didn't enjoy having a heated and air conditioned garage

I'm fairly sure the previous owners had turned the 2 car garage into office/play space complete w/ carpeting and a dividing wall or two, so it might be have been considered OK during that, and based on the live wiring stuffed into the ceilings, I think the conversion back to a garage wasn't done by folks who were concerned w/ code.

 

[Skellyii]

Houses built before a certain date normally had vents in the garage, I have some rental properties that were built in the 60s-80s that were equipped that way. Sometime in the 90s, at least around here, that became a no-no.

 

[bluedog225]

I recall some study that said there was an increase in disease burden for houses with attached garages. Forget which illnesses.

 

[kaymccampbell]

Once you close off the ducts, and repair the drywall, you should be fine. Finally finishing the drywall in my shop stopped the stinks dead.

 

[PoorUB]

I would seal off any shared duct work to the house very well.

A HRV or ERV will help with odors but might not work in the winter as it will probably just freeze up unless you heat the garage. In the summer months just simply having a small exhaust fan running all the time will help, 50 CFM bath fan will be plenty. It will ventilate the garage and keep the garage in a slight negative pressure.

 

[fastsvo]

In the summer months just simply having a small exhaust fan running all the time will help, 50 CFM bath fan will be plenty. It will ventilate the garage and keep the garage in a slight negative pressure.

That's an interesting idea to use a bathroom fan. I was considering installing a fan directly on my gable vent in the garage (it's exposed in the finished space - not in attic) since my "classic" car does bring in a lot of fumes inside the garage. Wouldn't 50 CFM be too small when demand ventilation is required?

 

[PoorUB]

That's an interesting idea to use a bathroom fan. I was considering installing a fan directly on my gable vent in the garage (it's exposed in the finished space - not in attic) since my "classic" car does bring in a lot of fumes inside the garage. Wouldn't 50 CFM be too small when demand ventilation is required?

Depends on the size of the garage, but a 24x24 foot garage and a 50 CFM fan will exchange all the air in 1-1/2 to 2 hours. It will not do much to immediately remove exhaust fumes from a running car, but over all it should keep the air fresher and keep the garage in a slight negative to help keep fumes from entering the house.