Danfoss Ally 1.18 set external temperature to Radiator Covered TRV

[luka6000]

@stevefal

Am I correct that with this, as with any scheme where there is an external thermometer updating the TRV at a relatively high rate, that battery consumption will be significantly higher?

No. This works as designed by danfos with only difference you’re using your own temperature sensor or calculation.

I’m assuming that with these TRVs (mine are Danfoss Ally), a “thermostatic” mechanical element inside the device makes the real-time valve adjustments, and the motor moves that assembly according to the desired setpoint - in the same way that the big knob does on traditional TRVs.

It doesn’t work like that. There is no mechanical thermostat inside. There is a valve and a PID regulator which is an automation algorithm that tries to keep the measured temperature at setpoint by opening and closing the valve at calculated percentage.

Whereas with external sensing on an electronic unit, the effect of the external input is to “adjust the knob” at relatively high frequency in order to outsmart the thermostatic element - thereby using the battery each time.

Do I have this right?

No, you’re wrong. By using external temperature sensor you’re adding better data to the algorithm which is good and works as designed.

What you’re describing is external calculation of valve percentage opening. This is not the case here.