Air conditioning supply duct in the attached garage ceiling

I have a house that I inspected that the homeowner added a supply duct vent in the attached garage ceiling.

Since this is a supply only and the return is still in the main part of the house, what safety statement have some of you used to call out the vent in the garage.

Communicating the risk of car exhaust gases.

Thanks in advance.

I do not know for sure what the law of the land is


If the a/c is not on and pumping air out then it is an open pathway.

Besides mine whose air runs constantly? just my 2 cents but I likely would not have even thought of it at the time, especially since my garage is just storage. I would definitely mention it but if it is NEVER used for vehicles or turned into an office I would likely “verbally” tell the client no problem. I would likely write it up as a defect to cover my a s s. I say good thought and catch.

Thanks Michael

You are welcome :slight_smile: Not sure if I helped any :slight_smile:

Extreme safety concern.
Recommend removing supply duct immediately.

Ducting in garage is an issue due to firewall penetration but also a high risk of introducing toxic fumes into the living space.

This is so dangerous you should immediately notify the seller.

While a garage may be conditioned…
… it must be Independent of the Home.

Thanks everyone!

Firewall issues plus creating a negative pressure on the rest of the home.