Uh.. r290 is propane.. r134a is propane as well.. with additives to make it non-explosive.. So therefor running 290 with 134a is not a problem.. You can run straight 290 as well.. It works better then 134a..
Once again
R-290 = Propane (same kind you use in your grill)
R-134a = Propane with additives to make it non explosive
It's just a Daewoo 1/20HP compressor.. nothing special
