ᐅ House Electricity Consumption – Usage Figures for Comparison

Created on: 30 Jan 2018 20:43
M
mading
Hello,

I know there are many factors affecting electricity consumption, so it might be a bit of guesswork. Still, I want to give it a try.

We have a ground-source heat pump (deep drilling). We heat about 170 sqm (1,830 sq ft) with it and don’t have large electricity consumers like an aquarium, etc. Our house meets the KFW 55 standard.

Currently, we use roughly 30 kWh per day on average for everything (heating and regular electricity). We rarely have temperatures below freezing at night. When I calculate the consumption over 30 days, it comes to about €250 per month in winter. Of course, consumption is naturally lower in summer.

Does anyone have comparable numbers? We just moved in in October, and I’m wondering if the heating system is working properly (efficiently) and if the output from the ground loop is as expected.

Looking forward to your feedback.

Greetings from Lake Constance,

mading
J
Joedreck
3 Feb 2018 22:02
Not if the content within a tank is used up or replaced. In that case, Legionella bacteria do not have time to grow.
B
bernie
4 Feb 2018 07:57
If the water is constantly moving and you use enough water daily (it doesn’t have to be the entire volume), then there are no issues with legionella.

(P.S.: Even if the upper part of the stratified storage tank is at 70°C (158°F), the middle may only be around 40°C (104°F). According to your concern, legionella should form there as well.)

But now back to the topic. I would appreciate it if more people shared their electricity consumption. --> Please specify household electricity separately from heat pump electricity.
M
mading
4 Feb 2018 08:20
Regarding legionella: do you also have a circulation pump? I adjusted/reduced ours, since it also consumes electricity (now it runs from 6-9 and 17-20).

Yes, I’m surprised that the temperature is actually 5°C (41°F). It's from a borehole 130m (430 feet) deep.

I’m still considering lowering the temperature, but according to the heating technician, it always depends on where the sensor is located. It can be installed at different heights, either higher or lower. The higher it is, the lower the temperature can be set.
N
Nordmann
6 Feb 2018 21:17
I have turned off the circulation. However, our distances are very short; the bathrooms are either next to or above the heat pump.
I would lower the hot water temperature until Madame complains[emoji6], no matter where the sensor is located.
Legionella is not an issue with regular use, but you always have to be a bit careful.
N
Nordlys
6 Feb 2018 21:36
My thoughts on the domestic hot water supply. We didn’t install this recirculation pump at all. When do we actually need hot water? Each person showers for three to four minutes in the morning. That’s it. There’s no need for constant circulation day in, day out. We keep the water temperature at 60°C (140°F) because with two people, it stays standing for a long time. The kitchen only needs cold water. The dishwasher uses cold water. The washing machine uses cold water. The coffee machine uses cold water. Washing hands, brushing teeth—cold water is fine. Honestly, a two-person house without a bathtub like ours doesn’t really need centralized hot water; instead, one electric instantaneous water heater (Stiebel Eltron) under the bathroom sink and one under the kitchen sink is enough. That’s it. Our building inspector just said this wouldn’t comply with the energy-saving regulations.
J
Joedreck
6 Feb 2018 21:40
It's a shame; for low consumption, a tankless water heater is often sufficient and very hygienic.
Turning off the circulation can apparently cause hygiene issues. I would recommend programming it well in terms of timing.
By the way, with short distances, it is a pointless energy waster. But that can no longer be changed.