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.
M
Mastermind117 May 2018 21:4942,000 kWh of generated heat with only 6,600 kWh of electricity consumption almost seems unrealistic.
This would correspond to an average annual performance factor of 6.6.
Typical values for a ground-source heat pump are between 4 and 5.5.
The heat demand for typical modern houses is between 6,000 and 12,000 kWh.
So the reported generated heat could be reasonable.
However, the stated electricity consumption must have some error, or is there a photovoltaic system on the roof that reduces the electricity demand, especially in summer and on sunny winter days?
This would correspond to an average annual performance factor of 6.6.
Typical values for a ground-source heat pump are between 4 and 5.5.
The heat demand for typical modern houses is between 6,000 and 12,000 kWh.
So the reported generated heat could be reasonable.
However, the stated electricity consumption must have some error, or is there a photovoltaic system on the roof that reduces the electricity demand, especially in summer and on sunny winter days?
Saruss schrieb:
@spooky0815 :
I just looked up some comparison values:
For just under 4 years: 6,600 kWh electricity consumption for:
According to the heat pump, 42 MWh energy (16.2 for domestic hot water + 25.8 for heating)
With a runtime of 4,545 hours and fewer than 6,000 compressor starts.
Mastermind1 schrieb:
42,000 kWh of heat produced with only 6,600 kWh of electricity consumption hardly seems possible.
That would be an average annual performance factor of 6.6.
Typically, for ground source heat pumps, it ranges from 4 to 5.5.
The heat demand for common modern houses is between 6,000 and 12,000 kWh.
So the amount of heat you mentioned could be realistic,
but there must be an error in the reported electricity consumption, or is there a photovoltaic system on the roof that reduces electricity use especially during summer and sunny winter days?No, I really have such a good annual performance factor. This is because everything is well coordinated, and my ground source temperature after long cold periods still stays above +5°C (41°F), usually rather around 8–9°C (46–48°F). At the same time, I can operate with low flow temperatures (without an electric auxiliary heater, using hydraulic balancing), at 0°C (32°F) outside temperature I am still well below 30°C (86°F). The temperature difference the heat pump has to work with is therefore very low, so the compressor operates on the high end of the performance coefficient chart.
The measurements (e.g., electricity) are made with a calibrated meter, by the way (although the cost savings from the heat pump electricity just barely break even for me).
S
spooky081517 May 2018 22:19Thank you all for the feedback – Sarrus, your data is very insightful. My main goal will be to minimize compressor starts and reduce the runtime of the electric heating element. The domestic hot water was set to 52°C (126°F), but 48°C (118°F) is certainly better.
Regarding adjustment of the heating curve, I will gladly continue to read and gather information here on the housebuilding forum.
During the construction phase, my plumbing company had deeper holes drilled and chose a larger heat pump with safety margins. Apparently, they were not very knowledgeable on the subject. My heating curve was set to a maximum of 28°C (82°F), which probably explains the many starts.
Can someone explain the point Mastermind1 made regarding individual room temperature controllers? Why is it counterproductive to set these to zero in individual rooms? Or did I misunderstand something here?
Regarding adjustment of the heating curve, I will gladly continue to read and gather information here on the housebuilding forum.
During the construction phase, my plumbing company had deeper holes drilled and chose a larger heat pump with safety margins. Apparently, they were not very knowledgeable on the subject. My heating curve was set to a maximum of 28°C (82°F), which probably explains the many starts.
Can someone explain the point Mastermind1 made regarding individual room temperature controllers? Why is it counterproductive to set these to zero in individual rooms? Or did I misunderstand something here?
M
Mastermind117 May 2018 22:31spooky0815 schrieb:
Thanks to everyone for the feedback – Sarrus, your data is very insightful. My main goal will be to minimize compressor starts and reduce the running time of the heating cartridge. The domestic hot water was set to 52 degrees Celsius (126°F)... lowering it to 48 degrees Celsius (118°F) is certainly better.
Regarding adjustment of the heating curve, I will continue to research and learn here in the housebuilding forum.
My plumbing company had drilled deeper holes during the construction phase and selected a larger heat pump with additional capacity for safety. Apparently, they were not very knowledgeable about the topic. My heating curve was set to a maximum of 28 degrees Celsius (82°F), which likely caused the many starts.
Can someone explain the point Mastermind1 made about individual room thermostatic valves? Why is it counterproductive to set them to zero in individual rooms? Or did I misunderstand something? A heat pump requires a minimum flow rate. Check the technical data sheet of your heat pump. If the heat pump was selected too large, this becomes even more critical. Usually, it will specify a minimum flow rate of x liters per hour (liters per hour).
On the underfloor heating manifolds, you can read the flow rate set for each heating circuit during operation. This is often given in liters per minute (liters per minute). You can convert this to liters per hour and you will see that it is already tight to meet the minimum flow rate.
If your individual room thermostatic valves close too early (because room temperatures are managed very strictly), then one heating circuit after another will close, and the heat pump will either shut down because the supply or return temperature has been reached (for the remaining heating circuits) or it will switch off for safety reasons to avoid a high-pressure fault.
This means that your throttled individual room thermostatic valves act as a bottleneck.
Individual room thermostatic valves really only make sense in rooms that are used infrequently...
And even nowadays, as long as all rooms are within the insulated building envelope, you heat through the adjacent rooms. Even if you turn off heating completely in one room, the temperature in newer houses (not exactly 40 years old) only drops by 2-3°C (3.6-5.4°F).
Even if you don’t go below the minimum volume flow, the return temperature rises more quickly when you close some thermostatic radiator valves (TRVs), and the heat pump also stops working. In all cases, you will definitely have more frequent cycling. In a well-insulated house, you should be able to set all TRVs to 30°C (86°F) and lower the heating curve until you reach a comfortable temperature. (The only possible issue might be bathrooms where there are too few heating circuits.)
Even if you don’t go below the minimum volume flow, the return temperature rises more quickly when you close some thermostatic radiator valves (TRVs), and the heat pump also stops working. In all cases, you will definitely have more frequent cycling. In a well-insulated house, you should be able to set all TRVs to 30°C (86°F) and lower the heating curve until you reach a comfortable temperature. (The only possible issue might be bathrooms where there are too few heating circuits.)
S
spooky081517 May 2018 22:37Thanks, Mastenmind1, for the explanation – I understand the principle. Basically, we have a fixed setting on the controllers in the house and never adjust them. The bedrooms are set to zero, as is the guest room, which is the only one that gets adjusted depending on the situation. The rest remain constant.
I have one more question: if my wife wants a cozy warm bathroom floor, should we lower the base temperature and turn the room thermostat up fully, or raise the base temperature and lower all the other controllers in the house?
I have one more question: if my wife wants a cozy warm bathroom floor, should we lower the base temperature and turn the room thermostat up fully, or raise the base temperature and lower all the other controllers in the house?
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