Direct valve control of supported TRVs

[EliasKrause]

Description

First of all, thanks for this great integration!

I'm sorry if this is a bit lengthy and perhaps should have been split into two posts (Direct valve control and user-definable min/max opening of independent TRVs). However, I believe they are tightly connected, so it made most sense to combine them here.

Direct valve control of supported TRVs like Sonoff TRVZB.
Support direct valve control for TRVs that support it - i.e, RoomMind sets a heating request directly in percentage instead of setting an artificial temperature value of the TRV.
Side note: The Sonoff TRVZB seems to be popular among users of other integrations like Versatile Thermostat, as it is very inexpensive, works 100% locally through Zigbee and supports direct valve control, i.e. 0-100% opening of the valve.

User-definable min/max opening of independent TRVs
In addition to direct valve control, it should ideally be possible for the user to set a minimum opening percentage as well as a maximum opening percentage value of each TRV.

Without it, different radiators in a single room may heat at uneven levels.

Use case

Currently, when heating is requested, all TRVs open the valves to 100%. This may work but creates needlessly high bursts of heat, which can also affect the return temperature (high return temperature is penalized by the district heating company).

With support for direct valve control, RoomMind could directly control how much heat the TRVs lets through.

Rooms with more than one TRV
Even if some TRVs support independent variable valve control, that will not be optimal for rooms with multiple TRVs as the individual TRV's needs to know at what opening percentage the radiators actually begins to heat (and also at roughly what percentage water is fully flowing and opening the valve more will have no further effect).

Example: If RoomMind requests heating to X degrees for a room with multiple TRV's and partial opening of the valves then is requested (let's say 20%), it may lead to one of the radiators in the room taking all of the heating load if the valves of other radiators doesn't let hot water through until a higher opening percentage.

With direct valve control:

• Room requests heat to 30%
• TRV1 is set to min_opening = 20, max_opening = 60, so gets an opening value of 32%
• TRV2 is set to min_opening = 10, max_opening = 45, so gets an opening value of 20,5%

Alternatives considered

I am currently using RoomMind to control a Versatile Thermostat climate entity (which in turn controls 3 Sonoff TRVZBs in a single room).

The VTherm entity is set up with minimum and maximum opening degrees for each of the TRV's so they heat evenly, and in addition they are never allowed to open the valves past a percentage where the radiators would get too hot and cause spikes in the return temperature to the district heating.

It works, and for me, RoomMind creates a much more even temperature in the room than I managed to get with only VTherm. However, the setup is quite a Frankenstein monster as RoomMind can't toggle the on/off states of a VTherm entity directly, so I have to rely on automations to do that.

I'm no developer but I realize that this feature suggestion might be complex to implement (and maybe deviates too much from the intention that you want RoomMind to be as plug-and-play as possible).
So, if you decide that this suggestion shouldn't be implemented, then a workable alternative could be to have RoomMind be able to toggle the on/off states of VTherm entities directly (it would tame my Frankenstein monster! 😄)

[maivorbim]

To add to EliasKrause's request, I am using several Z-Wave Eurotronic Spirit TRVs which expose a direct valve control number from 0-99, allowing me to directly control how much the valve is open when setting the TRV to Manufacturer Specific mode. Would it be possible to have RoomMind directly control the valve instead of the TRV temperature for better control?