ᐅ Experiences with Ground Source Heat Pumps

Created on: 23 Oct 2015 21:40
S
Saruss
Hello,
here I would like to share some experiences and data regarding my brine heat pump and deep drilling, based in part on the expert’s "questionnaire":

a) What is the soil composition on your property?
Up to 3m (10 feet) silty, fine sandy, clayey soil
Up to 4m (13 feet) slope debris, rock fragments
Then bedrock (mainly limestone)

b) How deep was the drilling?
Drilled twice to a depth of 72m (236 feet)

c) How much did the drilling cost?
€10,400 including double U-probes DN25
Grouting material with 2.0 W/mK thermal conductivity
Permitting process (building permit / planning permission)
Pressure-tight house entry at the basement and underground routing of supply lines (about 25m (82 feet))
Filling/draining equipment, filling, pressure testing, etc. (all inclusive)

d) How much did the system cost?
System: Tecalor TTc 05 with heating output at B0/W35 of 5.8 kW and coefficient of performance (COP) of 4.8
Cost: €9,800

e) Were there any difficulties during installation, if so, what kind?
Because the water used to flush out the drilled material during drilling seeped away, a "small compressor" was needed to blow it out with air. However, it had to be placed on a neighbor’s property who had not yet started building. The machine was the size and approximate weight of a 20-ton truck but was off-road capable. This caused a 2-day delay because the compressor first had to be transported to our site. No additional costs were charged.

f) How is the daily operation?
"Like a refrigerator." Once the parameters on the heating system are correctly set, the only thing that should be done is occasionally reading the information/data such as operating hours and source temperature. Otherwise, it runs "on its own," just like any heating system. When the door is closed, the unit is virtually inaudible. Very discreet since, apart from the cabinet in the utility room, nothing else is visible (all brine pipes are underground).

e) What are the operating costs for which living area?
Currently, a living area of 180sqm (1937 sqft) is heated, plus an additional 65sqm (700 sqft) of cellar space within the insulated thermal envelope (these rooms are around 15-16°C (59-61°F) on the coldest days). From September 2014 to September 2015, 2,000 kWh of electricity was consumed for heating and hot water (2 adults, 1 baby, 1 toddler). The house is a KfW-70 standard building according to the 2009 energy saving regulations, which already met the required technical standards before the central ventilation system with enthalpy heat exchanger was installed (we decided to add this after the initial applications).

f) to be continued ....

Note regarding the comparison of the coefficient of performance (COP):
Since optimizing the heating curve and settings at the end of last year, the system has had a COP of about 5.5. Operating hours are around 1200; the deep borehole was drilled approximately 20% deeper than initially recommended by the companies, at our own request.
Tarnari18 May 2021 21:00
Most people probably won’t receive an exemption and will just leave it non-functional.
@nordanney, you’re actually the first person I’ve come across in various forums who has actually succeeded in doing this. Everyone else I’ve read about or heard from recommends it but hasn’t done it themselves. We implemented it using our KNX switches. They can control the heating actuators via temperature sensors. But they don’t. The result is the same, and for us there was no extra cost since we would have installed them anyway.
G
guckuck2
18 May 2021 21:17
He didn’t make it. Only found one who signed his Willi underneath despite the missing ERR.

It was the same for me 😀
Tarnari18 May 2021 21:34
guckuck2 schrieb:

He didn’t manage it. Only found one who signed off with his declaration of conformity despite the absence of the ERR.

It was the same for me 😀
Or like that xD
If that’s the case, it should be stated clearly, as it has nothing to do with an exemption.
N
nordanney
18 May 2021 21:49
Tarnari schrieb:

If that is the case, it should be stated clearly, as it has nothing to do with an exemption.
I did 😉. Prefer pragmatic solutions...
Tarnari18 May 2021 21:53
nordanney schrieb:

I have 😉. Prefer pragmatic solutions...

OK, reading is learning. I read your post again. You actually do not mention an exemption. That makes me happy because my core statements remain valid and yours is simply not to do it if possible 🙂
A
annab377
19 May 2021 07:23
nordanney schrieb:

Buffer tanks and domestic hot water tanks are unrelated.

Well, I thought that because there are often combined tanks.
So, a domestic hot water tank (hot water storage tank) is sufficient. If you don’t have a fresh water station, then a smooth tube heat exchanger is the best solution? Or are there other alternatives as well?