Church with 19 Mitsubishi Heat Pumps w/o wifi

Energy
1

I am assisting a church with significantly reducing their carbon footprint. Aside from the multiple areas they are tackling (e.g., insulation, weatherization, windows, etc), I’m researching any means to be able to control their 19 Mitsubishi MSZ-GL09NA heat pumps with the church calendar and adaptive “smart” thermostats, so that they don’t have to have them all running all the time, and Google calendar entries can be encoded so that a script can interpret when an activity will be taking place in a specific room (e.g, “room 104: 1300-1400”) and ensure that room is at the right temperature when that activity begins, and turn off the heat pump when the activity ends (if no other activity is scheduled in that room afterwards).

I’ve been using Home Assistant for a few years now, and find it heads and tails better than OpenHAB which I had used previously, so I’m sold on it.

I don’t belong to this church (which does not have a large membership), however, so will be turning this over to someone there who is able to take it on afterwards. Hence, any solution should be able to be maintained by someone of intermediate programming skills.

Solutions I have researched:

  1. Add the wifi component PAC-USWHS002-WF-2 to each unit, controlling the units with Kumo Cloud, utlilzing the Kumo Cloud interface. However, I’ve heard recent horror stories about Kumo Cloud reliability, so am reticent to recommend such a solution.

  2. Employ a smart wifi thermostat with HA integration: My first thought was Ecobee, which I’d researched in the past. But now looking here in the forum I see Ecobee has taken away the local interface, and the overall current solution is somewhat convoluted, and may have more complex maintenance than I am seeking.
    Also, I understand the Mitsubishi’s own thermostat is proprietary communicating, which means that another thermostat could only send On/Off signals, not taking advantage of the high efficiency multi-stage aspects. However, it appears there is an interface component that may be able to handle that with some thermostats (Ecobee not listed) - PAC-US444CN-1

My questions:

  1. Does a single Home Assistant on an RPi 5 have the ability to control 19 thermostats from script parsing a calendar with room-encoded entries such as Google Calendar (or similar)?

  2. What are the other smart thermostats with reliable HA interfaces that would work with a Mitsubishi MSZ-GL09NA, assuming the need for a PAC-US444CN-1 interface?

Any pointers are welcome, thank you!

2

Adding the Ecobee thru the Homekit integration remains local and definitely not convoluted. It’s doesn’t require any Apple products.

2 Likes
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Another option is using mitsubishi2mqtt by connecting an esp8266 to the ac (cn105 port) for local control

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More details on this thread

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Thank you for this potential solution idea. I had considered more detailed approaches like this, though having someone at the church support this added control system layer who might not be technically proficient enough is a concern.

Also, each unit has an MHK2, which would be used if there were an outage in the solution I’m recommending. I’ve heard that some CN-105 control additions blocked the use of the wireless remote. Is that a concern here?

5

I’m not sure for the MKH2 since it’s using the same cn105 port.
You could ask in the thread if anyone’s using MKH2 with another wifi controller

Looking at this adapter here

You could make a simple custom pcb by just soldering all the connection points for 5v, gnd, tx, rx to to another 5 pin jst PAP female adapter

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@Stephenn

Any reason to believe that controlling 19 Mitsubishi MSZ-GL09NA units is too much for an RPi 5 Home Assistant communicating with Kumo Cloud? I plan to have the schedule controlled by the church’s calendaring system, such as Google Calendar, as each newly scheduled activity by date, time, and room is entered as they are reported to the church secretary.

7

I wouldn’t think that would be a problem. There are a bunch of people here running much bigger systems on a Raspberry Pi4 but I defer to the experts to correct me if I am wrong.

8

That will blow your electronics for sure. People have done that in the past.

You need an active CN105 splitter if you want to keep using the MHK2 and also be able to control it through HA. There are a few options out there. I know “CoolAutomation” sells just a splitter, or if you want something more sophisticated/smart get a ClimaControl.