In some areas, the cost of propane is cheaper than electric --- and the desert sure does get cold at night. We prefer to use our furnace rather than leave an electric heater plugged in and running while we sleep. I used to pay insurance claims and those electric heaters can start fires. If you are awake and present, you can react to signals of danger and prevent a fire - not so much when you are sleeping. Many rural houses heat with propane furnaces, have propane clothes dryers , propane kitchen stoves etc so I also do not understand the people afraid to use their furnaces.