ᐅ What annual electricity consumption should I specify in the energy contract?

Created on: 9 Jun 2017 10:21
B
BigFlow
Hello,
we will have two separate meters: one for the regular household electricity and one for our heating system. This consists of:

- Air-to-water heat pump with an outdoor unit for underfloor heating
- Exhaust air heat pump with a 200-liter (53-gallon) water tank for domestic hot water
- 150 sqm (1,615 sq ft) of usable space

When setting up the new electricity contracts, I would indicate 3000 kWh for household electricity (which has been roughly the consumption so far). For the heating electricity, I am unsure. I was thinking of 5000 kWh. Do you think that will be enough, or should I set it higher from the start? There are many varying reports on the consumption of such systems, so I prefer to estimate on the higher side to avoid unexpected additional charges.

Regarding these special heat pump tariffs with time-of-use restrictions, has anyone experienced the problem of suddenly running out of hot water while showering?

Thank you in advance.
Florian
ares8310 Jun 2017 21:32
Is a flow temperature of 35 degrees Celsius (95 degrees Fahrenheit) not a bit high for underfloor heating?
B
BigFlow
10 Jun 2017 22:55
That is the value from the heating load calculation, but thanks for the tip. I will ask the heating engineer about it when I get the chance.
Kaspatoo25 Jun 2017 12:33
ares83 schrieb:
Is a 35-degree supply temperature for underfloor heating not a bit high?

In my opinion, that is normal. I have heard this in various conversations with different SANs, and I have also seen similar specifications from manufacturers.
G
G-Star1988
14 Jul 2017 11:52
Hello everyone,

I’m joining in here because I’m facing exactly the same issue. What should I specify?

KfW 40
Air-to-water heat pump Rotex HPSU compact
Ventilation system Viessmann Vitevent 300
Underfloor heating
Living area 145 m² (1560 sq ft)

According to the energy certificate, the following values are calculated:

Heated floor area 182.51 m² (1965 sq ft)
Final energy demand 12 kWh/m²·a
Primary energy demand 21.40 kWh/m²·a

Can I simply calculate the initial value by multiplying the final energy demand by the heated floor area, so 182.51 m² × 12 kWh/m²·a = 2190.12 kWh? Or should I use completely different values for a first “annual consumption” estimate?

Thank you in advance
T
trendyandi
20 Jul 2017 10:39
Our consumption (2 adults + 2 toddlers; air-to-water heat pump, KfW70, 150 m² (1,615 ft²)):
Standard electricity: just under 2,000 kWh per year
Heat pump electricity: 1,500 kWh high tariff + 2,000 kWh low tariff
P
Peanuts74
4 Aug 2017 11:24
Lumpi_LE schrieb:
I would check the heating load calculation to see what it says; you can use that as a rough estimate, it will probably be less. 5000 is a bit too much...

In our case, 5000 kWh per year easily goes through the electrical system. However, that's with an indoor temperature of about 24°C (75°F) throughout the house and my wife’s frequent long showers...

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