heating electrically a "back yard" report

pianotuna wrote:
The cost of running the compressor compared to the watts of heat extracted is about 100% more than running plain electric resistance heat at the lowest operating temperature for the "pump".

Don, I'm not sure that your comment above came out as clearly as you intended it to.

Here's my way of talking about heat pumps:

It's much less expensive to get heat from a pure air-to-air heat pump system than from a pure resistance heat system -> when outside temperatures are such that an air-to-air heat pump system can deliver heat. That's of course because heat pumps merely transfer heat that already exists, versus creating new heat as resistance heaters do.

We have had a couple of heat pump systems for about 37 years in our all electric powered residence. Our newest heat pump is a state-of-the-art high efficiency (Trane XL16C) air-to-air one with complete computer control of it's variable speed compressor and variable speed circulation fan. Even though it uses auxiliary resistance heat strips for fast warmups if you want it, in it's fully automatic compressor-only mode it can still deliver heat and keep our interior warm (71 degrees F) with outside temperatures in only the high 20 degrees F range - as a matter of fact it had to do this again this past Sunday evening.

So .... in an RV park with pay-as-you-go electric and outside temperatures not much lower than the 40-45 degree F range - a heat pump roof unit (without heat strips) set to heat mode should result in lower electric charges from the park than what would result from use of a resistance heater in the RV.