I've noticed some seriously knowledgeable HVAC folks here, so I'm looking for advice.
We have renters in the walkout basement in our 4yo home. The basement is on the same HVAC unit, different zone (via electronic baffling) as our main floor. They like it cold. So it's 40 degrees outside and they're still running A/C! It's a ground floor space so I can understand why they wouldn't want to sleep with the windows open (I don't think they use the windows regardless, tho
; convo hasn't happened yet).
So what happens is the A/C runs to cool their space down, turns off, then the furnace turns on immediately to heat the space upstairs.
First question, is this bad for the system? I've always been under the impression it's really bad for the A/C compressor to be trying to cool 70 degree air indoors when it's 20-30 degrees colder than that outside. It also feels counterintuitive that, even with the baffling, the system would just be fighting itself. But maybe the baffling makes it OK?
Second, anyone have solutions that aren't obvious to this problem, of keeping 2 zones on the same units very different temperatures? The obvious one is them opening windows when they're home, and if it comes to me asking them to do that b/c they're damaging the A/C, it has to be done. But I want to be sensitive about it -- they're awesome renters otherwise.
Or are today's systems advanced enough that I have nothing to worry about?!
Thank you!