Is is possible to disable the fan when the internal unit is idle (heat mode)?

[enomam]

Hey all,

My MSZ-AP units, once they reach the desired temperature, they switch to idle mode. In idle mode, though the compressor stops running, the fan continues to run. I understand that this is to maintain airflow, so the internal thermostat has an up-to-date temperature. The side effect of this though, is that it makes the room drafty.

Is there a way to disable this function, especially as some of us use external thermostats? I've seen (theoretically) that it can be disabled by snipping the JR01 jumper - but was wondering if there's a less drastic solution via software?

[echavet]

Hi, Sure it sounds possible to me. I'm not really sure it is a good idea to interfere with the heatpump thermostat (as I would not exclude that the air flow is thermally neutral). But you could try. I think it could be handled by a HA automation. You would track for state changes on the stage sensor (ex:sensor.esp32_hp_stage_sensor is you named it "stage sensor"), and call Climate services to force the fan speed. As far as I remember, it seems to me that my heatpump slows the fan very low when it is in idle mode. But the silent mode could be again slower. Le ven. 10 mai 2024, 04:43, enomam ***@***.***> a écrit :

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Hey all, My MSZ-AP units, once they reach the desired temperature, they switch to idle mode. In idle mode, though the compressor stops running, the fan continues to run. I understand that this is to maintain airflow, so the internal thermostat has an up-to-date temperature. The side effect of this though, is that it makes the room drafty. Is there a way to disable this function, especially as some of us use external thermostats? I've seen (theoretically) that it can be disabled by snipping the JR01 jumper - but was wondering if there's a less drastic solution via software? — Reply to this email directly, view it on GitHub <#94>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAYTHBFLCEUHMAB4VEB7OFTZBQX4NAVCNFSM6AAAAABHP23ATCVHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZWGYZTQMRZGU> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[enomam]

I think the control I'm looking for is called " Thermal Off Fan Operation (Heat Mode)".
I think it's low by default (which causes drafts), so want to set it to off (there's no "off" fan speed :( )

Also - the "stage sensor" is low when the unit idles (and, is sometimes low when heating too :/ )

[enomam]

You know what - I think it's related to the stuff being investigated here: https://github.com/echavet/MitsubishiCN105ESPHome/wiki/Dictionary-of-Messages-on-CN105-Serial

and here:
SwiCago/HeatPump#39

[echavet]

Oh yes, that's the "paleontologist" branch of the project! 😜
It's pure research!! I'm very proud of the contributions from @disruptivepatternmaterial to the project. There are plenty of things to discover about this protocol. And plenty of things that I don't master at all!
Perhaps @disruptivepatternmaterial will have a better Idea about your question.
Look at the documentation he published here:
"Setting 125: When in Heat mode, once set point has been reached, fan 1) stays on, or 2) turns off
Value: 1 (default) – fan stays ON once set point is reached
2 – fan turns OFF once set point is reached"
#39 (comment)

[disruptivepatternmaterial]

Yes some units have settings of what to do in these states. Mine can do that. For the record, it turns off the head unit fan, not the outside one - that is independent.

I think if you follow some of the notes between @echavet and I on those settings, I am concerned that the dictionary is really different from unit to unit. Keep in mind I have in this house and they are all of the same general type and I live in North America.

I kind of stopped working on that part too because I really was after trying to find how to change the +/-2C of auto, which I was unable to find...instead I started working on an HA auto...

[enomam]

Sorry for the delay.
Is there any testing/debug I can do on my end to establish the "dictionary" for my unit, and where (if?) "setting 125" can be controlled via software?