Check out the Inogen One.It's a small battery-operated concentrator. I've been using mine over two years with no problems at all. I don't leave pilot lights on anyway (too many years on boats), so I never give the propane a thought. I have Medicare and a supplement, so there was no cost to me. Get the double batteries, it comes with 12Vdc and 115vac chargers. I think you'll be pleased. Except as a satisfied user, I have no connection with this company. BTW, the flame for your frig is outside.