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.
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.
I read through this topic last night in bed (we are about to start building a house, and I started having some doubts about an air-to-water heat pump / ground-source heat pump) and found some articles that seem trustworthy to me.
The Association of Private Homeowners reportedly conducted a study with Weberhaus and took samples. It seems that elevated or too high values were frequently found in heat pumps there.
According to the article, heat pumps should generally not be used for hot water preparation unless an additional heating element is used to regularly heat the water to 65°C (149°F), or better yet, a heat pump that can reach 65°C (149°F) on its own.
Heating elements naturally cause high energy costs – I’m not sure how sensible heat pumps that reach 65°C (149°F) on their own are for a single-family house.
Overall, I am now a bit uncertain whether to choose an air-to-water / ground-source heat pump with subsidies or a gas boiler that can reliably and efficiently reach 65°C (149°F) and costs significantly less. (The article states that for “typical” single-family houses, the investment/annual costs are: air-to-water heat pump 13,000/1,066, ground-source heat pump 23,000/793, gas boiler 5,500/830.)
In addition, there are costs for regularly heating water to 65°C (149°F), which apparently are not included.
Since I’ve only found this one article (from the Association of Private Homeowners) and am still researching, what are your thoughts? A photovoltaic system could potentially save some of the running costs of a heat pump but would also require an additional investment. For the ground-source heat pump, you can get a 35% rebate from BAFA, so instead of 23,000 it costs about 15,000. The issue with legionella remains unresolved.
The Association of Private Homeowners reportedly conducted a study with Weberhaus and took samples. It seems that elevated or too high values were frequently found in heat pumps there.
According to the article, heat pumps should generally not be used for hot water preparation unless an additional heating element is used to regularly heat the water to 65°C (149°F), or better yet, a heat pump that can reach 65°C (149°F) on its own.
Heating elements naturally cause high energy costs – I’m not sure how sensible heat pumps that reach 65°C (149°F) on their own are for a single-family house.
Overall, I am now a bit uncertain whether to choose an air-to-water / ground-source heat pump with subsidies or a gas boiler that can reliably and efficiently reach 65°C (149°F) and costs significantly less. (The article states that for “typical” single-family houses, the investment/annual costs are: air-to-water heat pump 13,000/1,066, ground-source heat pump 23,000/793, gas boiler 5,500/830.)
In addition, there are costs for regularly heating water to 65°C (149°F), which apparently are not included.
Since I’ve only found this one article (from the Association of Private Homeowners) and am still researching, what are your thoughts? A photovoltaic system could potentially save some of the running costs of a heat pump but would also require an additional investment. For the ground-source heat pump, you can get a 35% rebate from BAFA, so instead of 23,000 it costs about 15,000. The issue with legionella remains unresolved.
What exactly do you want with this obsessive 65°C?
Legionella bacteria are not an issue in single-family homes, and there are no regulations requiring it. You might consider it for a 1000-liter (264-gallon) tank, but definitely not for the usual 100-250 liter (26-66 gallon) tanks found in single-family homes.
And of course, the electric heating element should be turned off. But it’s rarely needed, only possibly in an extremely cold winter. Especially with a brine-to-water heat pump, it’s not needed at all, as long as the heat source isn’t incorrectly sized.
Legionella bacteria are not an issue in single-family homes, and there are no regulations requiring it. You might consider it for a 1000-liter (264-gallon) tank, but definitely not for the usual 100-250 liter (26-66 gallon) tanks found in single-family homes.
And of course, the electric heating element should be turned off. But it’s rarely needed, only possibly in an extremely cold winter. Especially with a brine-to-water heat pump, it’s not needed at all, as long as the heat source isn’t incorrectly sized.
S
Strahleman3 Jun 2020 10:10Teemoe86 schrieb:
In addition, there are the costs of heating the water weekly to 65°C (149°F), which are usually not included.The so-called legionella control cycle is often discouraged. Briefly heating the water is frequently not sufficient and can actually make legionella bacteria more heat-resistant. There are several articles available if you search for legionella control cycle.In a single-family home, with a properly sized domestic hot water storage tank, the water is typically replaced often and regularly enough that a critical number of legionella bacteria usually cannot develop. If you are still concerned, you might consider using a fresh water station. This is hygienically optimal since domestic hot water is only heated immediately before use.
Unfortunately, this statement is not found in the article. It is unfortunately very generalized.
I have now specifically searched further and was able to find statements with additional search terms indicating that the warning is aimed at multi-family houses with heat pumps, where different precautions are possible.
Other discussions from 2010 I found show opinions that vary widely.
In general, there seem to be fewer problems if there is no circulation line at all (if you have one, definitely do not turn it off...) and the volume is smaller. Since only two people will live in our house, water usage is limited – usually showering every two days, otherwise just some warm water in the morning/evening for washing the face, etc.
Currently planned for the build as standard is the "Arotherm Split VWL 75/5" with the "uniTOWER VWL 78/5 IS" with 190L (50 gallons).
If it really only costs around 2000 more due to the BAFA subsidy, which apparently is not available for an air-to-water heat pump, to switch to a domestic hot water cylinder, it might make sense for me to switch to a domestic hot water cylinder. Is that realistic?
How much is the additional cost for the fresh water station? From the 2010 posts, I read that it would only reach 40°C (104°F) with that. That would definitely be too low for me – especially if you want to wash something by hand in the kitchen.
I have now specifically searched further and was able to find statements with additional search terms indicating that the warning is aimed at multi-family houses with heat pumps, where different precautions are possible.
Other discussions from 2010 I found show opinions that vary widely.
In general, there seem to be fewer problems if there is no circulation line at all (if you have one, definitely do not turn it off...) and the volume is smaller. Since only two people will live in our house, water usage is limited – usually showering every two days, otherwise just some warm water in the morning/evening for washing the face, etc.
Currently planned for the build as standard is the "Arotherm Split VWL 75/5" with the "uniTOWER VWL 78/5 IS" with 190L (50 gallons).
If it really only costs around 2000 more due to the BAFA subsidy, which apparently is not available for an air-to-water heat pump, to switch to a domestic hot water cylinder, it might make sense for me to switch to a domestic hot water cylinder. Is that realistic?
How much is the additional cost for the fresh water station? From the 2010 posts, I read that it would only reach 40°C (104°F) with that. That would definitely be too low for me – especially if you want to wash something by hand in the kitchen.
T
T_im_Norden3 Jun 2020 13:05You can consider air-to-water heat pumps; just check the list from the Bafa and verify the annual performance factor with the heat pump calculator.
I have no idea where the notion comes from that air-to-water heat pumps should not be subsidized.
Regarding legionella: try to find a case in recent years where it occurred in a single-family house.
I have no idea where the notion comes from that air-to-water heat pumps should not be subsidized.
Regarding legionella: try to find a case in recent years where it occurred in a single-family house.
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