What Are The On/Off And PID Of TRV?

ON/OFF: similar to the control mode of heating temperature controller, using set temperature + start back difference switch valve: For example, when the temperature is set to 20℃ when the room temperature is 18℃, the valve is 100% open, 19℃ valve is 75% open, 20℃ valve is 50% open, 21℃ valve is 25% open, 22℃ valve is 0% open.
PID: This algorithm is more complex, but we should pay attention to one point, when the set temperature changes, the first action of the valve opening will change relatively large, so in a relatively short time, do not change the set temperature too much, otherwise it is easy to appear the room temperature is too high or too low.