We are RV campers and like to use the Electric Oil-filled Electric heater to supplement the propane heater. Especially at camp grounds with electric hookups. It is much better to use their electric then to use my propane. When camping off the power grid we need to use the propane furnace.
We never set our Electric Heater over a #3 setting and most of the time use the middle heat setting.
This is the Oil Filled heater we like to use with its low profile. This type of heater has no visible flame or red hot heat core which makes it one of the safest type of heaters to use in the trailer especially with small kids and animals. They are also very quiet in operation - just go CLICK every now and then. These do not have a fan but we will use the O2COOL 10-inch AC/DC/D-CELL portable fan behind one if we want to move some heated air aorund the trailer.

We also alot of the times plug an extension cord into the camp ground pedestal 20AMP SERVICE receptacle and plug our small electric heater into that. This does not draw from the 30AMP SERVICE our trailer is connected too.
Roy Ken