If it's not too humid, the old Sanyos will work down to about 8F.
My alarm is set for 11F, so I can start getting the back-up ready.
Last night wasn't too cold (the above post is from yesterday).
I don't like to run them under 10F. Space heater efficiency..
But, it was humid around here. My sensor showed 95% RH.
I was getting a ton of defrost cycles. Had to use some space heaters.
They actually did most of the work. The Sanyos didn't hardly came on..
Killed the space heaters when I got up, and the Sanyos worked okay.
They were using about 1/2 the power of those wasteful space heaters..