I have a small back porch that is approximately 110 square feet. The entire back porch in enclosed. The porch walls are as follows: 2 walls are exterior walls of the house, one wall is the exterior wall of the garage, and the fourth is a sliding glass door.

I want to put a small A/C wall unit on the porch. The problem is that the sliding glass door takes up the entire outer wall of the porch. There is no place to install a unit without replacing the door with a regular 32' or 36' door. I don't want to do this.

Is a portable air conditioner my only alternative? I could route the exhaust through the garage wall and then to the outside. But, I would prefer a wall unit. Any ideas?