Air conditioning return

I was at a 2 story house that was built in 2003.

The entire 1st floor was a garage space.

Last year the owner finished off 1/2 of the 1st floor as living space and added a 2 ton split system for cooling.
Now the garage is on the left and the living space is on the right side.

They added a small extra bathroom on the far left corner of the garage and only ran a supply air duct with no return.

Shouldn’t this space have a return to function properly?
The job was permitted with the county (but this may have been added after the permit was signed off):roll:
The extra bathroom was cool.

Left side Center non a/c Right side
Extra |
Bath |

The living space should be separated from the garage space, fire and air exchange wise. I’ve seen finished basements with no return, I always comment about it, but sometimes installing return ducts is cost prohibitive (not our problem to figure out), but certainly mention it in there too.

Jumper return duct.

You don’t want a return in the bathroom.

Good point.

As a home inspector there are locations that you should know that RA is not allowed by code.

Garages, Kitchens, bathrooms and within 10 feet of a gas fired appliance

Why not? :p:p:p

Well everyone has a fetish. :mrgreen:

My point was that since the the separate room is not attached to the living area section, return air cannot go under the door to keep the air flow moving.

Just wondering.

So you are saying that this separate room will cool ok without air returning to the handler. See attached sketch.

You mean like this one…:shock:

hepa filter

That is exactly what I am saying no return installed from any bathroom. If the bathroom was within the home or the conditioned area yes it would draw a return from under the door but would be mixed with a % of other return/ or conditioned air.

In your diagram being its strictly a enclosed bathroom in the garage no return is allowed and the supply air is just wasted as it is just like blowing air into a bottle until the bottle gets full then it overflows any where there is a opening. In your diagram the room will cool and heat somewhat because the room pressurizes enough for the air to escape into the garage area where it is just wasted energy. A typical case of someone not having a clue what they were doing.

You should not have a return in the bathroom.

But you can not have a supply without a return.

If you don’t have a return in the bath, supply air will blow out the ventilator or just through the wall/door openings to the garage.

A jumper duct is not a return, just a pressure relief duct from the bathroom back to the house. Like a neutral on an electrical circuit, it would’t work without one.

If you do not have an air return to this bathroom, you will depressurize the main house and cause numerous other potential issues.

The bathroom does not require A/C, just heat.
The room should have it’s own heat source.

That never happens now days

Does the bathroom have a self closing self sealing door.? What prevents the door from being left open and CO or other fumes from entering the living space via the duct? I believe a jumper would help. How are they running this duct all the way over there.? Hopefully not exposed flex through the garage.

Thank you for the education info.