I’m trying something new, which is to compute the weather compensated temperature using the forecast temperature, about 2 hours in the future (using data from OpenWeatherMap.com).
{See simple script in this thread to fetch the data via their API}
My rationale is thus:
- when the future temperature is going to be significantly warmer, the heat pump will work towards a lower temperature with improved CoP
- when the future temperature is going to be significantly cooler, ramp up the flow temperature while the ambient temperature is warm, again improving CoP
Compare red line in the chart below, calculated from the forecast temperature, to the orange line, calculated from the current temperature. It’s generally lower in the morning, and higher in the evening.
Bottom of the chart shows the OutdoorTemperature supplied by a sensor on the external HP unit, and the actual RecordedTemperature from the local weather station. Note how the OutdoorTemp is coarse to the nearest degree, and has local dips similar to what MyForest was seeing in this thread, directly related to when the HP was running. I much prefer using the smoother, more precise readings from the weather station (from the future!). (I also factor in the effective temperature, but that’s another topic).
It’s been cold and snowy up here today, so not sure how this would work on a nice spring day. For my next trick, I need to figure out how to delay the start of the heating in the morning, like some “Smart” room stats can do. Basically, have it start as late as possible while still getting the house up to a comfortable level. Better if there’s sun on the panels by then too. I was kinda hoping that suppressing the flow temps would do this for me for free.