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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

#81

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.

How about sleep? Ideal temperature is 18C.

That is 64F. Not everyone considers that an ideal temperature.

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

#82

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…

> 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

Awesome

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

#83
post #38

Earlier quoted context omitted.

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 ca…

> because it is both less efficient and will wear more while pulling the temperature down

That's just not true. Aircon is a heat pump. It pumps heat more efficiently when more heat is available to be pumped.

Warmer indoor air increases evaporator temperature. A higher evaporator temperature means that the system operates with less temperature lift. This means that the system does less work (per BTU pumped) to cool a house that is hot inside, than one that is already conditioned inside.

Equipment longevity also tends to be increased with less-frequent, longer runtimes than with more-frequent, shorter runtimes. There's less temperature cycling, fewer in-rush current events, and the lubricating oil in a running compressor is actively circulated to the parts that need lubricated. Reducing the number of compressor start-ups is a good thing; these machines like to run.

So even if same number of BTUs enter the home and need pumped out whether the aircon is running or not, then: Letting things warm up inside when there's nobody home to care about that constitutes an improvement in a broad number of ways.

Reality is even better: On a hot day, a house that is hot inside takes in fewer BTUs than one that is cool inside, due to the reduced temperature delta between indoors and out. When we have fewer BTUs coming in, then we have fewer BTUs that we must ultimately pay to pump back out.

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

#84
post #62
post #57

Earlier quoted context omitted.

>Single stage hvac systems tend to have better performance in the max capacity cooling cases (Texas) and last significantly longer than units that rely on non-linear electronic devices. Why?

Inverter systems have more conversion losses than single stage. Most of the time, I definitely intend to run my system as hard as it can. There are only 4-5 weeks out of the year where variable speed would make a meaningful difference. Semiconductors wear faster than copper wires and contactors and are much harder to replace. I can take a part from my neighbor's condensing unit and it would almost certainly work in m…

> Most of the time, I definitely intend to run my system as hard as it can. There are only 4-5 weeks out of the year where variable speed would make a meaningful difference.

The system never catches up, even at night?

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

#85
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.

Lots of digital thermostats (both relatively dumb and very smart) allow for temperature adjustments to be locked within pre-set limits. If your customer disdain drives you to want that kind of thing, then just find one and install it.

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

#86

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.

Isn't the thermal cycling greater outdoor than indoor because of the differences in the outdoor temperature between day and night? So most ordinary materials indoors should be fine with a delta of even 10 Kelvins/10 Celsius/18 F. All of the material thermal failures I can think of come from localized and more extreme sources: electronics, lightbulbs, washing/drying clothes, washing dishes in a dishwasher. Water below…

Yes, it's MUCH worse outdoors, but indoor temperature (and humidity) swings are not good either. I guess most people here just haven't paid enough attention to it as it's a very long-term effect, but definitely noticeable.

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

#87
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.

Everyone I know offline keeps their house at a constant temperature year-round, yet apparently it's controversial enough to be a downvoted opinion here? WTF?

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

#88
post #17

Earlier quoted context omitted.

I understand, and I could make it clear in the description that AC is capped at 18 degres C minimum (65F), so people who like it very cold could skip my airbnb. Some AC can go ridiculously low ( http://news.bbc.co.uk/2/hi/uk_news/england/3144803.stm ). I do not want to change the temperature remotely, I just want to not have the AC used to extremely cold temperature. I am fine to advertise it to weed of people who li…

I should have bothered to do the conversion... when I read your post I was immediately reminded of the recent laws in Italy that capped AC in public spaces to a minimum of 25C... 18C is awfully cold for a residence! Most programmable thermostats in the US do have built-in limits for device protection. I've never met anyone who sets AC in a home to lower than 68F and that is an absolute extreme. Most central AC system…

Room temperature varies by country and region: https://en.wikipedia.org/wiki/Room_temperature

18C is not uncommon in the UK. They seem to like it colder. Italy is down south so 25C may already be getting cold for them. Then there's the Indians who like it closer to 30C...

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

#89
post #79

Earlier quoted context omitted.

Single stage forced air / air handlers AC systems are basically only found in North America because they are so grossly inefficient and because most people in the rest of the world realize they can save money by not having all of their rooms ran off the same system. The rest of the world runs on mini splits for that reason.

I don't understand why it's so common for Europeans to act like they speak for the entire rest of the world outside of North America.

[dead]

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

#90

Earlier quoted context omitted.

How about sleep? Ideal temperature is 18C.

That is 64F. Not everyone considers that an ideal temperature.

As in scientifically proven to be biologically ideal, proven to have the best sleep outcomes. You can have different preferences of course, doesn’t change what’s ideal.
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