That's because the air still has to be recirclated over the heat strip to warm it, just as it takes a while for the AC to cool it down when the trailer is hot, where as the furnace instantly starts putting out warm air. I was amazed to see how much propane the furnace uses. I've looked for a couple of ceramic space heaters, but everyone is out of them for this season, I don't have much camping time left where heat will be needed, but I'll have them for next season.
2013 F250 XLT
I now have a Keystone Outback, but I try to help when I can.
Bitter Gun Owner