Can you use 134 in home air conditioning units?

NO NO NO you will ruin the compressor.. your compressor is designed to use R-22

Believe it or not, you can use Propane in place of freon 22.

http://yarchive.net/ac/hydrocarbon_recipes.html

BE GOD DAMMED CAREFUL AND DOUBLE CHECK FOR LEAKS BEFORE YOU DO SO!!! propane is actually listed as freon #290