i’m using a reversible heat pump as heat source in the winter. As summer’s really hot this year, I’ve tried the reversible feature and noticed (as to be expected) it’s most efficient during cold conditions outside.
Therefore I’d like to optimize the times the heat pump will cool. Heating is also affected, as a rule would be simply applicable to the heating season. Reaching a target temperature is not as important as efficient operation.
My setup has this item T_Outside, which shows the current outside temperature. Persisted by RRD a chart like this is available showing temperature and time:
Here are my first thoughts on this:
Approximately time based will narrow the time window when the heat pump may start
Clear falling temperatures in this time window indicate preferable times
When deciding, my rule evaluates the rightmost data (current time)
Now my question: How to detect using persistence and rule engine?
I’m not entirely sure what your question is. but I’ve been wondering about something similar:
what time should openhab turn on the heat so that the room is ready at a given time.
like you mention, with heat pumps there are a few factors
the outside temp
the inside temp
the target temp
the heating performance of the room. ie how long does it take to heat
If this is your question, and you want to implement this in opebhab rules, you’d need to come up with a formula that perhaps runs in a rule every 5 minutes and turns on the heat pump. Otherwise I think that it might be beyond the basics of openhab rules and would most satisfactorily involve some machine learning.
