ᐅ Air-to-Water Heat Pump: Current Consumption and Data

4lpha0ne schrieb:

Do you have a ventilation system?

If no explanation is found by next winter, it might be interesting to take a look with a thermal imaging camera (maybe borrow one somewhere?).

Yes, we do, but sometimes a balcony door is left open for about 30 minutes (because of the cat or for airing out). Also, when cooking, we ventilate thoroughly, and so on. We simply love to open doors and windows when needed, even if it costs a bit of energy.

However, the pump only runs for about 3 hours or so, which is manageable.

Actually, right now is the perfect weather for an air-to-water heat pump + solar + battery system: outdoor temperature above 6°C (43°F), so no energy-intensive defrost cycles. The heat pump regularly draws the battery down almost completely for heating purposes (here, we’ve felt a maximum outdoor temperature of 13°C (55°F) for weeks). Still, thanks to the long daylight hours, there is enough solar yield even without direct sunlight for immediate consumption and battery charging (12.8 kWh), with minimal ineffective feed-in to the grid. The only thing that felt completely pointless was all the money spent on the terrace and garden... 😉 😡

Bookstar schrieb:

If there is no insulation yet, that doesn’t help me.

Yes, it does. An uninsulated house is just as "good" as your insulated house. So the problem isn’t with your heat pump, but with the house itself.
Who knows how "good" your house really is, and not just nicely calculated on paper.

@Bookstar
I think your house is fine.
We have KfW 40+ standard and the heat pump is still running every day.
Room temperature is 22 - 23 degrees Celsius (72 - 73 degrees Fahrenheit).
There has been wind for weeks, sometimes strong, outdoor temperature between 1 and 15 degrees Celsius (34 - 59 degrees Fahrenheit), and it is almost always overcast, so no solar gains.
I have no idea how anyone could manage without heating under these conditions.

What were the results of the Bowerdoor test?

Same here, daytime temperatures around 12-16°C (54-61°F) inside, little sun, dropping to about 4°C (39°F) at night. So far, there have been one or two days without heating; otherwise, it runs about 3 hours a day plus hot water preparation. KfW 40 standard with blower door test just above passive house level.