Okay, so i'm dying in a Texas Heat Wave and trying to figure out what to do. My Central AC unit went down and it's 1,500 to fix, and i don't have that.
I have an old AC Unit from my old house, and i was wondering if i could do this.
Picture: 
Black lines is the house itself, blue lines are the "entry room", which is a Bar that leads to the outside world, red is the garrage that connects to the Bar (but not the house).
There are no windows except sliding glass windows.
My idea is to put my AC unit in the doorway with the back facing into the Bar and hang a sheet over the AC so the hot air goes into the Bar, and the cool air goes into the house.
Will this work?
I also don't want to burn out my old ac unit.
Best Answer
This would be completely and fundamentally unworkable. Air conditioners must be installed so that heat is pumped to the outside of the structure.
The entry room would become excessively hot and humid. Remember, water vapor condensed on the cooling coils of the unit is conducted to the outside of the a/c unit where some is re-vaporized and some drips as liquid. This heat and humidity could damage the walls of the entry room.
The temperature in the entry room would be much higher than the ambient outdoor temperature and this would greatly reduce the efficiency of the refrigeration cycle of the a/c. And there would be heat flow through the wall of the entry room back into cooled space.