Hard power cycling your AC unit is bad for it and may eventually kill it. The fan needs to run for a bit after the compressor turns off. This affects large ACs more than small ones, but it may cause damage after a while. If your AC unit has an RF remote, I'd recommend using something like a Broadlink unit to control it.
this post was submitted on 18 May 2025
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Unfortunately, it's got no kind of remote at all. It's a physical dial to turn it on to high low or fan high low and a physical dial to turn up or down the temperature setting.
That's why I got a smart plug for it to begin with because there were times when I would fall asleep at like 10 p.m. and wake up at 3 a.m. with the damn thing still running.
It is only a 550 watt unit, but I was not aware that hard power cycling it like that would eventually hurt it. So at least thanks for that information.
It'll be fine as long as you don't try and start it up again within a few minutes of turning it off.
Pressure just needs to slowly bleed from the high pressure side to the low pressure side of the compressor before it starts again, so that it isn't initially stalled against high pressure.
Idk how complicated the internal wiring is but maybe a solution here is a pair of shelly relays. One for the ac and one for the compressor fan. Then you could turn them on/off separately over wifi based on whatever logic you come up with.
It might be a good idea to get a power monitoring plug to get some data into what would save the most power while still keeping temps where you want it
Thankfully, my plug already has power monitoring built in.
Get a zigbee controller, install zigbee 2 mqtt. Set z2mqtt to channel 25 to lessen wifi interference. Buy third reality zigbee temp sensor. Use the temp sensor to control the ac plug. I use versatile thermostat from HACS to turn on off.
Buying a temperature sensor is in my future plans, but currently I'm too cheap to do so.
I used a cheap temp sensor to link the on of with the temperature further away in the room. Its more useful with space heaters it the winter.
Running it for 20 mins every hour during daytime is an interesting approach, id think it would be more effecive to do on 10 evey half hour but i suppose its really just a personal preference.
Have you done any measurements to see how effective it is 20mins every hour compares to every other hour?
Not yet. I'm thinking about modifying it, but haven't done so. Quite yet.
I have window AC units in my kids bedrooms. They stay off during the day, but turn on several hours before bedtime depending on the outside temperature. It isn't a terribly smart automation, just a "turn on at 4pm if temp over 100F, 5pm for 90F and 6pm for 80F."
Originally I was trying to do it based on delta t between the room and the outside and the target temperature and the estimated cooling efficiency, then I had to start figuring in how humidity and feels like temperature would affect things. And so after over thinking and over engineering it, I ended up at the stupid solution of just switching on at fixed times based on outside temperature being over a threshold and it works pretty well.
slightly off topic but are they smart ACs or are you automating them with a smart plug and if so how much power do they use? I am using a third reality plug which is capable of 15 amps but for a brief moment right when the thing starts up it can pull 17 amps for like half a second or less before settling down and that's why I'm wondering what you're using. My AC runs at 550 to 600 watts during normal operation.
Smart plugs, I have two on sonoff s31 reflashed with esphome and one on a third reality zigbee plug. These are all smaller units, about 8000 BTU.
But... I had to put the big one downstairs on a smart plug for completely different reason. It is a ge smart ac with wifi, but once in a while it gets into a state where when it tries to start up but consistently trips the breaker. So the smart plug simply cuts power for 5 minutes when it notices the ac is pulling more amps than what it is supposed to.
But yeah, I inspect regularly and try to avoid running these things when nobody is around. I had a 30amp smart switch on and outdoor outlet which would trip whenever I plugged in a weedwhacker and it ended up looking scorched, clearly rated for 30amp but not capable of doing even half that because the 16 amp breaker never tripped.