Air Conditioning - Why can't I Vent a Window A/C unit through the wall and into my garage?

I Have central air but need a Window unit/Through the wall unit, to supplement my central air.

I have a room over top my garage that I would like to put an
A/C unit in and vent onto the garage. It gets very hot in the
area that the coil and exhaust would be behind the wall.

I had bought a frigidaire 12000 BTU (window unit)from lowes and the first thing it said in the installation manual was not to vent it into
a garage. Why is this?

Are through the wall units any different?

I know about the split systems but they are usually $1500 or more.

Thanks, Frank

You wouldn't have the proper air flow in a garage for the a/c to remove it's heat..

You wouldn't have the proper air flow in a garage for the a/c to remove it's heat..

Are their any that work under these conditions?

Frank

The unit will work if vented into the garage........for a while. As the previous poster noted, the unit will not have enough air flow (cooling air for the condensor coil) to remove the heat it generates. Remember, the AC unit doesn't make the heat in the house disappear. Rather it moves it from one place to another (indoors to outdoors) and adds heat while this is happening (motor heat). As the unit runs, it will increase the ambient air tempreature in the garage to a point to where it will reduce the effeciency of the air conditioner to zero, not to mention make the garage a really un-comfortable place to be and finally damage the unit. . If you must vent it into the garage, you will probably have to install a vent system (thru wall or attic) to remove the heat from the garage. Either that or open a door or window in the garage when running the unit.
hope this helps

The AC unit will work, but will indeed heat up the garage. It may work a little overtime as the garage heats up.

But, the other consideration is that fire codes normally require a barrier between the garage and the living area. Putting a hole through the wall eliminates the fire protection. You may want to think this through a bit more.

bumpety bump bump