ᐅ Heat pump/ventilation system with excessive energy consumption
Created on: 24 Jun 2025 07:44
G
Gintonik
Hello forum,
My brother-in-law sent me a screenshot from his photovoltaic app. The values shown there seem illogical and much too high to me. As far as I can interpret, his photovoltaic system generated 38 kWh and additionally drew 12 kWh from the grid. That adds up to 50 kWh for the day. He has a KfW40 house built in 2022, with a Tecalor THZ 504 heat pump/ventilation system. He also uses this system to cool his house.
The total seems far too high to me, but I have no personal experience with a heat pump/ventilation system. I have now asked him to document the electricity consumption on the meter every evening to see if he really consumes what the app shows. I once had my energy flow meter for my photovoltaic system connected incorrectly, so it showed my generated energy as consumption.
In recent days, we had warm/hot weather. During the day, when the cooling runs, the photovoltaic system supplies electricity. In the evening, when the sun is gone, there is no more power from the photovoltaic system, but then cooling should no longer be necessary.
Do you have any experience with such systems?
My brother-in-law sent me a screenshot from his photovoltaic app. The values shown there seem illogical and much too high to me. As far as I can interpret, his photovoltaic system generated 38 kWh and additionally drew 12 kWh from the grid. That adds up to 50 kWh for the day. He has a KfW40 house built in 2022, with a Tecalor THZ 504 heat pump/ventilation system. He also uses this system to cool his house.
The total seems far too high to me, but I have no personal experience with a heat pump/ventilation system. I have now asked him to document the electricity consumption on the meter every evening to see if he really consumes what the app shows. I once had my energy flow meter for my photovoltaic system connected incorrectly, so it showed my generated energy as consumption.
In recent days, we had warm/hot weather. During the day, when the cooling runs, the photovoltaic system supplies electricity. In the evening, when the sun is gone, there is no more power from the photovoltaic system, but then cooling should no longer be necessary.
Do you have any experience with such systems?
W
wiltshire24 Jun 2025 17:18With some providers offering so-called "power cloud" solutions, the "cloud power" is mistakenly presented as self-consumption. This could also be the case in this screenshot.
Joedreck schrieb:
I think we have incomplete information. There is already a mechanical ventilation system with active cooling, a heated pool, and the pool pump. Maybe also an irrigation system? The heated pool is the typical round type, not a large in-ground basin. The pool heat pump requires about 3 kWh/day, based on what a friend told me about his comparable system. But yes, I will also deactivate the pool heater and monitor the power consumption.
wiltshire schrieb:
With some providers offering so-called "power cloud" solutions, the "cloud power" is mistakenly shown as self-consumption. This might also be the case in this screenshot.To my knowledge, he does not have a power cloud.W
wiltshire25 Jun 2025 07:42In any case, compare the values from the app with those from the meter.
Malle Zwabber schrieb:
I interpret the chart a bit differently, but maybe I’m missing something.
You don’t have a continuous consumption of 5 kWh between 8:00 AM and 9:00 PM. During that time, you are almost 100% self-sufficient (green line). Around 2:00 PM, there is a power peak of about 4.5 kW (orange line).
Overall, I find the consumption quite high. You are absolutely right, the "dark" orange line shows the consumption. Overall, between 8:00 AM and 5:00 PM, the consumption does not drop below 2.6 kW. The production is sometimes slightly above consumption, so the battery (blue bar) charges a bit before it empties relatively quickly again. If we assume that the cooling runs continuously at 1.5 kW, the rest of the household’s consumption at 1 kW is still relatively high. The question I have is whether the cooling should eventually turn off, or is it possible that it runs at full power all the time? My air conditioning can be set either to a target temperature (then it will switch off) or to “Alaska,” where it runs continuously at full load all day long.
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