Firstly, let me preface my remarks by stating that the discussion of hydrocarbon refrigerants on this board will usually cause one or more members to have a myocardial infarction.

The reason for this is the fact that such refrigerants may not be legal to use in your state and are also flammable if the system is ruptured. If you understand these risks prior to beginning any discussion of hydrocarbon refrigerants, then we have no need for a bevy of other members to post again and again regarding these issues.

So, to answer your question:

Propane, by iteself, is not the best choice for a refrigerant due to problems with it at higher ambient temperatures. However, when combined with isobutane, the mix is usually very good up to about 95°F. You can get such a refrigerant if you do a search on "Duracool". Their site gives you everything you need to know about it.

However, I state again............it may not be legal to use it in your state, and it is flammable.

Personally, I'm going to give it a whirl when the system on the SD takes a dive...........which is going to be soon.