ᐅ Heat Pump Energy Consumption in 2019 on a Monthly Basis

No idea where you got the fan heater from; there are also modern solutions. Everyone can do as they prefer. You can also simply increase the heat pump settings or use an instantaneous water heater with a higher temperature as a backup.

Low hot water temperatures with heat pumps have both advantages and disadvantages. I have mentioned both and hope I was able to help the person asking.

michert schrieb:

Manually open all ERR valves and eliminate significant temperature differences within the thermal envelope. Perform a thermal balancing and, if needed, heat the bathroom with a portable electric heater.

The ERR valves also consume a lot of electricity. I have 24 heating circuits, one ERR uses 1.5W. That adds up to over 300 kWh per year (!)

Check here, it was even mentioned in this thread...

Do you really have to scald your hand to effectively wash pans?

In fact, the cleaning result hardly differs whether you use hot or cold water. It’s the dish soap that does the work. It’s more a matter of perception.

Water has to be hot to clean properly. Pills have to be bitter to work. Things have to cost a lot of money to be any good...

Hi, I’m chiming in briefly because something seems odd with my peak/off-peak meter readings...

Here’s a quick timeline:

09/20/2019 Installation of both meters (heat pump and house electricity) 0 kWh
09/26/2019 Move-in
10/26/2019 Electricity provider change: 90 kWh peak, 90 kWh off-peak, 220 kWh total house use

At this point, it seemed strange to me that the peak and off-peak readings were exactly the same. I contacted the grid operator, and they said something like maybe the supplier doesn’t have different tariffs, so only one value is recorded (i.e., consumption = 90 kWh).

11/17/2019 266 kWh peak, 266 kWh off-peak
12/05/2019 I received a letter from the basic supplier saying that instead of 90 kWh, I have to pay for double, so 180 kWh.

I reviewed the peak/off-peak values, and since my last reading, they seem to be running differently: 313 kWh peak and 397 kWh off-peak.

Has something gone wrong here? Could the meter have recorded incorrectly, or were about 50% of the consumption allocated to peak and 50% to off-peak “booked”?

ares83 schrieb:

KfW55
Heated area 160 m2 (1,722 sq ft), underfloor heating
Standard rooms 21°C (70°F), living area (55 m2 (592 sq ft)) 22°C (72°F), bathroom 24°C (75°F)
Air-to-water heat pump with centralized mechanical ventilation with heat recovery
Hot water temperature 43°C (109°F)

January	459
February	400
March	410
April	153
May	147
June	36
July	36
August	26
September	155
October	156
November	235

That makes roughly 2600 kWh this year. After last year’s 3200 kWh, we are satisfied. However, last year included a week of emergency operation.
I optimized the heating curve myself last year; I haven’t had time to adjust it this year yet. I have adapted the flow rates to the calculations. I might tackle the ERR this winter.

Congratulations. Most heat pump owners dream of those numbers—it’s really close to the best possible. However, 43°C (109°F) hot water isn’t an option; that prioritizes comfort over efficiency.

Are you sure January and March are the same?

I think my consumption is about double yours. But I heat 70 m2 (750 sq ft) more, so that doesn’t explain it entirely.

Bookstar schrieb:

However, 43°C (109°F) for hot water is not an option, as comfort takes priority over consumption.

Until 10 a.m., the temperature is even only 42°C (108°F). Because of the 2-degree hysteresis, it can go up to 44/45°C (111/113°F). But I would never give up on comfort. That’s also why the bathroom stays at 24°C (75°F) the whole time, without an additional fan.

So far, the 43°C (109°F) setting has not reduced our comfort. When I take a bath, the water is 41°C (106°F), which is the hottest I can tolerate. We shower at 39°C (102°F), even after bathing, without any problem with running out of hot water. Our THZ 504 has a 230-liter (60-gallon) hot water tank, which has been sufficient so far. Since there is a lot of movement in the system, I have no concerns about legionella.

Most of the washing up goes into the dishwasher. Pans go in the sink, but even there the 43°C (109°F) water is already too hot for me. Everything still gets clean without much effort.

Yes, the numbers are almost identical for January to March. We didn’t really have many cold days here in the north near Bremen. The few cold days were scattered. A night at -10°C (14°F) and a day below freezing really takes a toll, with up to about 38 kWh of electricity used. Since our daughter was born in mid-January, it’s possible I read the consumption data a day late.