Why not design a TVR operated solely from the room stat. This would take away all these problems with incorrect temperature sensing. And should be considerably cheaper.
The current TRVs can already do that, so why design another one? I have several TRVs that are controlled by the temperature sensed by wall thermostat. I think the amount of money you would save in producing a separate TRV without the spinny temperature control on top would be far outweighed by the additional design and manufacturing costs of a new, limited use-case TRV.
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