Posted: 22/09/2013 at 17:42
I am sure that propane is for outside use as it doesn't freeze as quickly as butane.
So if you are planning on keeping the bottle outside it might be the best bet.
We gave up on parrafin because it made the greenhouse wet with condensation, I have no idea if gas heaters do this though. We now have an electric heater and have it on frost free setting and it keeps the atmosphere warm and dry.