Turned the little AC around.
Now it's in Heat Pump mode.
The inside and outside temps.
More inside temp(hall thermostat) .
After 10 to 15 minutes, the hot air was at 90 degrees. (pulling 22 additional degrees out of the 68 degree outdoor air).
The room went up to 75 pretty quick. (That 77 is the attic temp).
The
Heat Pump output was a fairly large volume of 90 degree air. It didn't feel as hot on my hand as my resistive space heater.
I guess the difference is the extra width of the air flow from the back end of the AC. I was surprised how quickly the whole room got hot.
This little AC started up slowly, but soon it appeared to be warming the room pretty well.
My guess is, it was doing about the same job as my 1500W space heater, but was doing it on 540W.
I think this test was a good indicator that an AC unit can be used for heating if you have some mild air available.
This tends to make me think my 25,000 BTU space heater idea just might work. It may not be 3 times as efficient as electric baseboard heat, but I'm pretty sure it will be at least twice as efficient.