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I added a non-wi-fi Mitsubishi AC to Home Assistant

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Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#31
post #12

Earlier quoted context omitted.

If you have same schedule every week, don't go on vacation, your kids don't have breaks, don't have seasons, then 'set and forget' dumb thermostat will work for you without any problems. For the rest of us we need some 'smartness' in our thermostats.

You shouldn't need to change the temperature regardless of those things. My house remains at 68-72F basically all the time. Thermal cycling accelerates aging of materials.

How about sleep? Ideal temperature is 18C.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#32

I’ve been working on a similar setup using the M5Stack NanoC6 and AtomS3 Lite, and put together a parts list and wiring guide on my site: https://serin-labs.com/parts.html . I also built a web flasher with firmware configured for those boards, so you can install directly from your browser without any fiddling or configuring. The ESPHome option uses the same echavet/MitsubishiCN105ESPHome project mentioned in the arti…

HN is awesome sometimes, I actually just installed 3 of your devices in my ACs to get them all wifi enabled. Worked perfectly, thank you!

Is it possible to flash them from Google home firmware to esphome without USB? I might move away from Google home soon but I'd hate to have to reopen up my ACs again.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#33

Anyone tried this on the Bosch units? Their WiFi module comes as an addon too.

Research it with an LLM. I've ordered all the stuff for Panasonic and Daikin after a deep planning session. It told me what connectors I need that Panasonic needs a level shifter. Both brands have open source libraries for the internal protocols and wiring. I wanted Zigbee so the ESP32 C6 was the way to go. The Panasonic units I have already have Wifi but most companies suck at this kind of thing. I couldn't get the Panasonic Wifi to pair with my router. Daikin also sell Wifi modules and people don't to like them.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#34

Earlier quoted context omitted.

You shouldn't need to change the temperature regardless of those things. My house remains at 68-72F basically all the time. Thermal cycling accelerates aging of materials.

Sounds expensive at the equivalent rate of 38 cents a kilowatt hour that I pay during the day.

Power is cheaper than things failing earlier than they could have due to thermal cycling.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#35

For anyone wondering why he would ever do this, it seems to be a type of hidden mini-split system used in euro-style shoebox flats, with a super-proprietary thermostat. Wi-Fi capability is an option at additional cost, but was not purchased. In the USA, wired thermostats tend to use standardized 24V wiring schemes, or 208V/240V for mains voltage heaters (electric heat, common on the west coast, especially in shitty a…

FYI this kind of thermostat is actually better. American style thermostat put your HVAC system in either on or off state (basically PWM), whereas this kind of communicating thermostat can tell the system what the temperature is, so they adjust power accordingly. I do wish they have standardized protocol though.

The thermostat is better only because it takes advantage of the inverter modulation capabilities in the heat pump. I don't have the sense that inverter modulation is the norm for most home ducted systems, even new builds in North America.

I've only observed ductless systems like this in retrofitted, older homes in Canada. And at that point they're usually not integrated with the home's existing heating system / thermostat.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#36

I'm hoping to get a mini-split system installed soon and thought I might as well look for something with HA integration. It's not easy. Some manufacturers like Samsung actually want to charge you monthly for cloud integration! Completely out of the question obviously. I came across this, and Mitsubishi is supposed to be good anyway. I would prefer something that's actually supported but I can't seem to find any other…

Fwiw I have a Samsung AC system and Claude was able to one-shot a custom web dashboard to control it.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#37

For anyone wondering why he would ever do this, it seems to be a type of hidden mini-split system used in euro-style shoebox flats, with a super-proprietary thermostat. Wi-Fi capability is an option at additional cost, but was not purchased. In the USA, wired thermostats tend to use standardized 24V wiring schemes, or 208V/240V for mains voltage heaters (electric heat, common on the west coast, especially in shitty a…

Is this "mini" split? This type of panels are pretty standard for office buildings in Japan. Usually networked into building management system somewhere. Most household mini splits come with an IR remote, and don't support these panels. Standalone third-party thermostats are rare.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#38

Earlier quoted context omitted.

Sounds expensive at the equivalent rate of 38 cents a kilowatt hour that I pay during the day.

Power is cheaper than things failing earlier than they could have due to thermal cycling.

Do you have any citation for thermal cycling through the range of an AC inside a house affecting the failure rate of any household goods? Based on my experience this does not seem likely to be the case: thermal effects tend to be exponential or high powers of temperature, and most thermal cycling that people worry about is on the order of 100C or more. 10/20C of variation seems unlikely to be relevant.

(There is a case where if your house is well insulated enough, then it can be worth avoiding cycling your AC during the day, because it is both less efficient and will wear more while pulling the temperature down and this can be worse than just leaving it running in a sufficiently insulated house. It still is probably worth turning it off if you're away for a week, though)

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#39
post #6

Does anyone know if this could be used to "cap" the AC settings ? It could be useful in an airbnb place, where I want to limit the lowest (e.g. 18 degres Celsius) or hottest (e.g. 22 degres Celsius) the guest can set the AC.

These panels technically lets you do everything you would ever want to on an AC control panel: https://www.mitsubishielectric.co.jp/ldm/slim/remotecontrol/

Or multiple AC units can be networked and managed over Ethernet: https://www.mitsubishielectric.co.jp/ldm/control/function/

People do start placing hand warmers on the panel if you lock them down too much, but what you asked should be possible in principle.

Re: I added a non-wi-fi Mitsubishi AC to Home Assistant

#40

My idea of HVAC is that it should be "set and forget", so "smart" is the polar opposite of what I want. The round Honeywell on the wall has been doing its job for the past few decades, and will likely last many more with only an occasional cleaning.

For some people they may only opportunistically (perhaps they have excess PV production at that moment) run their AC or temporarily turn it off when they temporarily have other power demands at that moment (eg running dishwasher, washing machine, microwave, kettle, etc) and don’t want to pay for grid energy while doing so. “HVAC” is essentially not a thing in houses in South Africa likely due to having a mild climate…

This is exactly the case in my household. Excess solar is pretty much worthless here, so with a smart AC you can dump the excess solar into your house as either heat or cold. This (currently) has a lot better ROI than installing a household battery. (Battery tech and availability might change this.)

I am enamoured by making dumb AC's smart by this method, since you probably have a lot less IT risks than by using the suppliers app. I think the trade off is between IT risk and mechanical / technical risk, since adding your own parts have an effect on warranty (or at least: willingness to repair by the supplier).

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