I've been trying to find some reputable info about what values to set for my heatpump. I'm using it for hydronic cooling, but I suppose it doesn't matter that much.
Correct settings for things like delta T, hysteresis, PID etc, that control how frequently the compressor is running and at what power level will be similar for a heatpump and a mini split. There is some difference because we're warming/cooling 15 tons of concrete rather than air, but principles will be the same.
I've been trying various things so things are comfortable now(hysteresis at 5C), but I'm not sure if I'm not making it run harder than it should at the same time(it is cycling every half an hour).
I found some articles online that claim "heat pump compressor should not be started more than 3 times per day", another article claims " it should run between 50%-80% duty cycle" and says nothing about starts. This is an inverter unit BTW.
Many claim a bufer tank is essential, others say if you have a fully featured unit that can modulate its power and enough flow it is not needed (I haven't got one). This obviously means the heatpump has to do all the control of the water temperature. Not an external mixing valve and pump.
So, do we have anyone here with knowledge of these things? For example my heatpump came with the following defaults:
Floor heating/cooling delta T -5C
Room temp delta T 2C
Hysteresis of 10C (insanity - imagine you're cooling your water to 15C. It will cycle between 10C and 20C. One will cause condensation, the other will be way too hot).
There are PID settings, but I noticed the compressor mostly runs or it doesn't. It doesn't modulate power much.
Some settings make little sense. For example there is "compressor on dT" which was set at 6C, cooling compressor load set to 4C and cooling compressor unload set at 0C. Which means a hysteresis of +10C from the setpoint.
There is a huge number of parameters to control. For example PID settings in EEVm set at 1250,200,12.
I'm trying to get some data collection going to see how parameters influence things, but it's difficult (I get a bunch of binary data without any idea how to interpret). With a relatively active heat pump forum here hopefully someone has gone through the same process.
Edit: Also, would'it be better to dial down the power and run the compressor continuously?
(I haven't been getting much in terms of answers for these heat pump threads, but hopefully someone can give some advice on this one).
Correct settings for things like delta T, hysteresis, PID etc, that control how frequently the compressor is running and at what power level will be similar for a heatpump and a mini split. There is some difference because we're warming/cooling 15 tons of concrete rather than air, but principles will be the same.
I've been trying various things so things are comfortable now(hysteresis at 5C), but I'm not sure if I'm not making it run harder than it should at the same time(it is cycling every half an hour).
I found some articles online that claim "heat pump compressor should not be started more than 3 times per day", another article claims " it should run between 50%-80% duty cycle" and says nothing about starts. This is an inverter unit BTW.
Many claim a bufer tank is essential, others say if you have a fully featured unit that can modulate its power and enough flow it is not needed (I haven't got one). This obviously means the heatpump has to do all the control of the water temperature. Not an external mixing valve and pump.
So, do we have anyone here with knowledge of these things? For example my heatpump came with the following defaults:
Floor heating/cooling delta T -5C
Room temp delta T 2C
Hysteresis of 10C (insanity - imagine you're cooling your water to 15C. It will cycle between 10C and 20C. One will cause condensation, the other will be way too hot).
There are PID settings, but I noticed the compressor mostly runs or it doesn't. It doesn't modulate power much.
Some settings make little sense. For example there is "compressor on dT" which was set at 6C, cooling compressor load set to 4C and cooling compressor unload set at 0C. Which means a hysteresis of +10C from the setpoint.
There is a huge number of parameters to control. For example PID settings in EEVm set at 1250,200,12.
I'm trying to get some data collection going to see how parameters influence things, but it's difficult (I get a bunch of binary data without any idea how to interpret). With a relatively active heat pump forum here hopefully someone has gone through the same process.
Edit: Also, would'it be better to dial down the power and run the compressor continuously?
(I haven't been getting much in terms of answers for these heat pump threads, but hopefully someone can give some advice on this one).
Last edited:
