Midea Inverter unit - How to cap compressor power instead of cycling on and off

[ctscasemod]

Hi All,

I have a midea air conditioner. It's a split type heat pump with inverter compressor.

The problem I have with this unit is that while operating in cold mode there are options to limit the compressor power to 50, 75 and 100%. Generally by setting the lowest one, this gives out a pleasant air output with little cycling.

On heating mode, there is no option to set the power The unit operates at full power, just throttling the compressor seconds before it shuts off. This makes it extremelly unconfortable. There is all this super hot air and then the compressor turns off and there is a bit of cold air before the fan turns off. It does this every 3 or 4 minutes.

There is an option to set the fan to quiet, but this results in the head pressures getting too high (it only modulates to 50%) and it cycles on and off just as bad as before, but because of the limited air flow it doesn't do wonders at distributing the heat.

So I have run an automation where I set it to quiet, and imediatelly set the fan to high. The compressor starts at 33% and after about a minute or so it starts ramping. First to 50%, then after another minutes it ramps to full power. So If I reset it every 3 minutes it seems to run acceptably, the air is blown at a confortable temperature and the unit doesn't cycle.

I have another unit on another house, this one an AUX brand. It still allows me to set up the power leves through the app, though I need to do this at every power on. For the most part I just leave it at 30% and increase if the temperature is too cold. On the largest rooms this means zero cycling.

So why can't the manufacturers do this, and is there any way to get pass this silly behaviour? Very little point in having an inverter unit if it doesn't really modulate...! I see their heatpumps have a wired controller and there is an option there to cap the power.
Would there be a service manual I could enter into?

Midea sells at least 10 different brands. I can't believe they would have a bad design, unless they deliberatelly remove functions to steer the consumer to a higher tier product?

[seanf]

Is there any way of fitting your own small plc?
Tap into the existing wiring and send the control signals you want each components driver to see?

[ctscasemod]

You mean the powerline communication with the outside unit? I thought about something like that, but I would need to reverse engineer that.

I have also wondered if I can open the circuit with the outside unit. That way I could, in thery, set it to quiet, open the wire and then do whatever I please with the indoor unit fan speed. I don't know if there is some sort of timeout, though.

I wonder why the heat setting doesn't give the option to throtle, when clearly the unit can do so (under cold mode). Would there be a technical reason to deliberatelly disable that feature? Can't see the compressor being starved of oil only when heating!

[seanf]

Is it one of these units that uses an EEV on cooling and then a capillary/fixed orifice on heating?