ᐅ Determine the electricity consumption of the air-to-water heat pump as a proportion of the total power consumption.

driver55 schrieb:

We probably need to start from “Adam and Eve” here…

So, we are talking about 2021, not 2020. (The house has only existed for 1.5 years).

The 7 kW heat pump is now known.
It would be helpful to have the indicated heat quantities and all relevant meter readings, each with the correct units.

Information about the house (150 sq m (1600 sq ft) ... 300 sq m (3200 sq ft), KfW certification or equivalent, with or without heated basement, number/age of occupants, location, room temperature(s), etc.) would also help to estimate the consumption.
The heat pump certainly has one or more integrated meters as well.

With an annual demand of 6800 kWh, I would guess about 4000 kWh for the heat pump and 2800 kWh for household consumption.
But let’s wait for the additional numbers…

We are talking about 2021. However, I can only provide electricity data for 2021. I didn’t record the other meter readings last year, so those values effectively cover about 1.5 years.
Our single-family house is 150 sq m (1600 sq ft), fully insulated to KfW40 standard or similar, no basement, two occupants both around 30 years old, located in Lower Saxony, with room temperatures around 20°C (68°F), warmer in the bathroom, cooler in the bedroom.

Tomorrow I will try to find the heat pump manual and check the reading. Without the manual, the only readings I have are those mentioned above.

Here are the other readings:

Separate meter at distribution box: 1,294.59 kWh
Heat meter: 12,082 MVh
Heat meter: 2,477 MVh – this one should be the one in the domestic hot water circuit.
Electricity consumption 2021: approx. 6,800 kWh

Almost 7000 kWh for a 150m² (1600 sq ft) KFW40 house sounds like a lot, but it could also include an electric car, sauna, mining farm, and so on.

What kind of unit is MVh?

I strongly suspect that the second meter is for the photovoltaic system!? The meter reading could be the feed-in?

The system will have an emergency shut-off switch, right? You could place a Shelly PM in between, which would then provide you with the consumption data. Especially with photovoltaics, having Shellys is quite useful because it allows you to analyze fairly well when, where, and how much electricity is being generated…

RotorMotor schrieb:

Almost 7000 kWh for a 150 m² (1600 sq ft) KFW40 house sounds like a lot, but it could also include an electric car, sauna, mining farm, and so on.

What unit is MVh?

For a cannabis plantation in the basement, the electricity consumption is too low again ….

The MVH will be in kWh. Over 1.5 years, that amounts to roughly 8,000 kWh of heat energy consumed by the house. That corresponds quite well to 150 sqm (1,615 sq ft) and KfW40 in my opinion.

Assuming 2,500–3,000 kWh of household electricity, you end up with an annual performance factor of about 2. That would be very poor, but it could be explained by the long and cold winter as well as the hot water usage. So, I would now take the time to optimize the hot water preparation and heat pump settings.

Of course, these are all just assumptions.

Joedreck schrieb:

The Mvh will be in kWh. Over 1.5 years, that roughly amounts to 8,000 kWh of thermal energy consumed by the house. That fits quite well with 150 m² (1,615 sq ft) and KfW40 standard, in my opinion.
Assuming 2,500–3,000 kWh of household electricity, this results in an annual performance factor of about 2. That would be very poor, but could be explained by the long and cold winter as well as domestic hot water usage. So I would now take the time to optimize the hot water production and heat pump settings.

Of course, these are just assumptions.

With “refrigerator temperatures” (20°C (68°F)) in a KfW40-rated house, I would have guessed a maximum of 2,000 kWh for the heat pump.
But where are the remaining 4,800 kWh being “burned”?
Or is it a normal household electricity demand combined with completely flawed hydraulics/floor heating?
Perhaps the domestic hot water temperature is set at 55–60°C (131–140°F)?

@TE: Your consumption remains a mystery.
We need more input.

I recommend recording all meter readings—including correct units—daily from now on, until all crystal balls here have been polished.