Mini Split AC limiting usage

Sandcruiser · 03-10-10, 02:20 PM

Hey all
I am about to start renting out my house as a vacation rental.

I have 4 minisplit AC units that we don't use much, but renters tend to set them at 16*C (60*F) and try to make a meat locker out of their bedroom... even if the doors are open or they aren't home.

So instead of spending $500/month on electricity (can be done, I assure you), I'd like to spend some time/money up front to see if I can limit their AC abuse.

First some assumptions:
A) If you travel to an exotic tropical location (costa rica) you should be ready to experience some warm temperatures- I'd like to limit the AC units to where they can't cool past about 70 degrees (21*C)

B) if you aren't in the house, it is okay for the temps to climb a little, maybe as high as 80*F (28*C), especially if they fall again when you return

C) If there is nobody home for more than 8 hours, I'd like the AC to just plain turn itself off. So if a maid or tenant forgets the AC completely, it won't try to keep the house cool for a week of emptiness.

My idea is pretty simple, but I'm not sure if it will work and/or if it will cause harm to the AC units.

I'd like to get a motion-sensor controlled thermostat that I can set to simply cut power to the compressor of the mini split system. If the interior temp of a given room drops below 70* degrees, the fan inside will continue to operate, but the compressor will shut down and refuse to make the room colder. When it warms up (and it will warm up, our outside temps are usually in the 90s) then the compressor will kick in again.

I'd also like for the motion sensor to kick up the temperature setting whenever it goes for over X hours without motion. Maybe set the lowest temp at 78* F when nobody is present. At night that feature would have to be overridden so that people who are sleeping don't awaken to a hot room.

Personally, I don't run the AC much and when I do, I run it at 78. But vacationers are a testy bunch, as a rule, and will almost certainly complain if they can't make the place cold. I just want to prevent them from sleeping under a comforter or sitting around in a sweatshirt on a 90* day.

ideally, the motion sensor or the thermostat could be set such that if it gets no input after 24 hours, it'll just shut down. I'll leave a note for the renters telling them that the AC shuts down every 24 hours unless they adjust the temp at some point, or something like that.

Thoughts?

Mostly, I seek input on the technical aspect: Can I wire into the compressor power source without frying something? that sort of thing.

Thanks!

03-10-10, 02:20 PM	#1
Sandcruiser Helper EcoRenovator Join Date: Apr 2009 Posts: 33 Thanks: 0 Thanked 0 Times in 0 Posts	Mini Split AC limiting usage Hey all I am about to start renting out my house as a vacation rental. I have 4 minisplit AC units that we don't use much, but renters tend to set them at 16C (60F) and try to make a meat locker out of their bedroom... even if the doors are open or they aren't home. So instead of spending $500/month on electricity (can be done, I assure you), I'd like to spend some time/money up front to see if I can limit their AC abuse. First some assumptions: A) If you travel to an exotic tropical location (costa rica) you should be ready to experience some warm temperatures- I'd like to limit the AC units to where they can't cool past about 70 degrees (21C) B) if you aren't in the house, it is okay for the temps to climb a little, maybe as high as 80F (28C), especially if they fall again when you return C) If there is nobody home for more than 8 hours, I'd like the AC to just plain turn itself off. So if a maid or tenant forgets the AC completely, it won't try to keep the house cool for a week of emptiness. My idea is pretty simple, but I'm not sure if it will work and/or if it will cause harm to the AC units. I'd like to get a motion-sensor controlled thermostat that I can set to simply cut power to the compressor of the mini split system. If the interior temp of a given room drops below 70 degrees, the fan inside will continue to operate, but the compressor will shut down and refuse to make the room colder. When it warms up (and it will warm up, our outside temps are usually in the 90s) then the compressor will kick in again. I'd also like for the motion sensor to kick up the temperature setting whenever it goes for over X hours without motion. Maybe set the lowest temp at 78* F when nobody is present. At night that feature would have to be overridden so that people who are sleeping don't awaken to a hot room. Personally, I don't run the AC much and when I do, I run it at 78. But vacationers are a testy bunch, as a rule, and will almost certainly complain if they can't make the place cold. I just want to prevent them from sleeping under a comforter or sitting around in a sweatshirt on a 90* day. ideally, the motion sensor or the thermostat could be set such that if it gets no input after 24 hours, it'll just shut down. I'll leave a note for the renters telling them that the AC shuts down every 24 hours unless they adjust the temp at some point, or something like that. Thoughts? Mostly, I seek input on the technical aspect: Can I wire into the compressor power source without frying something? that sort of thing. Thanks!