Experiences with brine heat pump

Hello,

I am jumping on this topic because it also fits the subject of "experiences." We are currently busy with preparations for building our single-family house. At the moment, we are particularly concerned with the topic of heating and especially the question "heat pump – yes or no."

I need your help. We currently have various offers, all based on KFW55 and gas condensing boilers. In addition, there is the usual solar thermal system and controlled residential ventilation.

As an option, we also had a brine heat pump offered. No matter how I calculate, the additional investment does not pay off even after 15 years. I wonder what I am doing wrong... what I am overlooking.

Regarding the numbers:

The additional costs after BAFA deduction and "gas connection savings" are about €11,000 to €14,500 (depending on the provider). I roughly assumed 16,000 kWh for heating and hot water (((160m²*50W/m²) + 500W)/1000 * 1900h)). Sorry, I know that is very rough.

Only at an average price of 9.5 cents/kWh over 15 years (which would mean about 13% increase per year) do roughly the same costs arise over 15 years. However, I assumed that there would be no price increases for electricity over 15 years, which is rather unrealistic. The costs for the chimney sweep and maintenance are included, as well as the costs for the basic gas fee and secondary meter fee.

Am I overlooking something in my calculation, or is it really only hard to make a profit? Many thanks.

Best regards

Hello,

I'm jumping on this topic because it also fits the subject "Experiences." We are currently busy with the preparations for building our single-family house. At the moment, we are concerned about the heating topic, especially the question "Heat pump - yes or no."

I need your help. We now have various offers, all based on KFW55 and gas condensing boilers. Additionally, there is the usual solar thermal system and controlled residential ventilation.

As an option, we have also been offered a ground-source heat pump. No matter how I calculate, the additional investment doesn't pay off even after 15 years. I wonder what I'm doing wrong... what I'm overlooking.

Regarding the numbers:

The additional costs after BAFA deduction and "gas connection savings" are about 11 - 14.5 thousand euros (depending on the provider). I roughly assumed 16,000 kWh for heating and hot water (((160m²*50W/m²) + 500W)/1000 * 1900h). Sorry, I know this is very rough.

Only at an average price over 15 years of 9.5 Ct/kWh (which would be about 13% increase per year) do the costs over 15 years become roughly equal. However, I assumed no price increases in electricity over 15 years, which is rather unrealistic. The costs for the chimney sweep and maintenance are considered, as well as the costs for the gas basic fee and secondary meter fee.

Am I missing something in my calculation, or is it really so hard to make a profit? Thank you very much.

Best regards

I don’t see any calculation; how should one give an error/note?

from on the road

Hi!

We are still in the process of finding a cost-effective and good brine heat pump. I have two questions on this topic. The first is a quick question for understanding... (1) What exactly is a buffer tank needed for? What are the advantages/disadvantages (if there are any) of it? So far, I have not noticed any buffer tanks with air-water heat pumps - but with brine heat pumps, this term comes up more often.
(2) Does anyone know the company "Brötje" - they probably come from northern Germany and we will likely receive an affordable offer with a device from Brötje next week.

Best regards & thanks for the help.
Gatho

With correct interpretation, one should only use one [Warmwasserspeicher], and not a buffer tank for heating, also actually not for ground source heat pumps (works very well for me). Physically, it is like this: The screed in the house has such an enormous storage mass, a few hundred liters of buffer water are nothing compared to that.

from on the go

So, finally can also, although there is still some fiddling with the heating system...

August
3 people, 240 sqm living space, Kfw70 Energy Saving Ordinance 2014, Vaillant Flexotherm 87/4, 140m drilling, circulation line (temporarily active), ventilation system

Heating 0 kW
Hot water: 66.79 kW
Household electricity: 335.21 kW
Water consumption: 9 m3

You mean kWh.