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.
S
Strahleman10 May 2020 20:48annab377 schrieb:
What do you think, how much more does a system like yours cost?We are currently still waiting for a quote for a fresh water station as an alternative to the planned hot water tank with heat exchanger. Since the current heat exchanger is supposed to come from Nibe and is quite expensive (1,400 euros gross), I estimate the additional cost for a fresh water station to be around 1,000 euros, excluding any extra costs for additional piping work and commissioning.
Case hot water storage tank: with what water does the heat exchanger charge the hot water storage tank? The brine-water heat pump heats the water to about 30°C (86°F) which is the supply temperature for the underfloor heating, but that doesn’t seem sufficient for hot water. Is an electric heating element added, or can the brine-water heat pump also raise the temperature further using the compressor?
Case stratified storage tank and domestic hot water station: did I understand correctly that your stratified storage tank only heats water for domestic hot water use, and your heating system is not connected to the stratified storage tank?
Even if I prefer to select a slightly larger tank (270 or 300 liters (71 or 79 gallons)), the water is constantly circulating inside, so it isn’t strictly necessary to fully use up the water every day, right? There is movement in the tank with every draw-off.
Case stratified storage tank and domestic hot water station: did I understand correctly that your stratified storage tank only heats water for domestic hot water use, and your heating system is not connected to the stratified storage tank?
Joedreck schrieb:
Keep hot water at a low temperature, but then choose the tank small enough so that the water is safely used up every day.
Even if I prefer to select a slightly larger tank (270 or 300 liters (71 or 79 gallons)), the water is constantly circulating inside, so it isn’t strictly necessary to fully use up the water every day, right? There is movement in the tank with every draw-off.
annab377 schrieb:
How long does it usually take for the heat pump to "refill" 90 liters (20 gallons) of water after the 180-liter (47 gallons) tank has been half emptied? Does it depend on the heat pump settings, photovoltaic electricity, etc., or does the heat pump typically start immediately to heat new cold water and make it available in the tank again? A heat pump with a 6 kW heating capacity will raise the temperature of 90 liters (20 gallons) of water from 10°C (50°F) to 45°C (113°F) in about 40 minutes.
If your heat pump is more powerful, for example 10 kW, it will of course be faster.
If the heat pump is allowed to use an additional electric immersion heater (e.g., 6 kW), the heating can be even quicker. However, the immersion heater is inefficient and usually not the primary method used.
The second question is when a heat pump (or any heating system) starts producing hot water. This is usually controlled by hysteresis, meaning the process starts when the temperature in the tank drops below a preset threshold. Once the temperature falls below this lower limit, the heat pump begins heating until it reaches an upper threshold. For example, if the hot water target temperature is set to 45°C (113°F) with a hysteresis of 2 degrees, heating starts below 43°C (109°F) and continues until it reaches 47°C (117°F).
Other parameters for starting and stopping hot water production can also be configured.
User Joedreck mentioned the option to set blocking times during which no hot water is produced. Personally, I find this a bit inflexible, but if it fits your lifestyle, it can work. It might be fine with consistent showering or bathing habits, but less so for families with shift work.
You also mentioned the influence of photovoltaics. This is possible, for example, via the "SG ready" feature of some heat pumps. If the PV inverter has an output signal indicating solar power production, the heat pump can be linked to this and can, for instance, temporarily increase the tank temperature above the usual setpoints. Instead of 43/45/47°C (109/113/117°F), you could allow an additional 5 Kelvin (9°F) increase when there is abundant and inexpensive solar electricity available on-site.
annab377 schrieb:
In the case of the hot water tank: with which water does the heat exchanger heat the domestic hot water tank? The temperature heated to about 30°C (86°F) by the brine-to-water heat pump (supply temperature of the underfloor heating) is probably not sufficient, right? Is an immersion heater added, or can the brine-to-water heat pump raise the temperature further using the compressor? Domestic hot water is handled in a separate circuit. It is heated directly by the compressor; however, because of the higher target temperature, this process is less efficient. Therefore, it is common to keep the hot water temperature as low as is reasonable. Heating engineers often recommend setting the storage temperature above 50°C (122°F). While this is convenient because the hot water supply lasts longer, it is inefficient. A target temperature of 45°C (113°F) is a good starting point. If you find that the storage volume is insufficient for your hot water needs, you can increase the temperature to gain more comfort, accepting reduced efficiency in return.
@guckuck2 Thank you very much for clarifying all the uncertainties. I will simply get a quote for a domestic hot water tank and, at the same time, for a stratified storage tank with a fresh water station, then see which option makes more financial sense. The downside of the fresh water station is that you always need to heat a few degrees more than you actually need later on (about 5 Kelvin). Plus, the additional cost of the fresh water station and stratified storage tank, as well as higher maintenance requirements and greater susceptibility compared to a simple hot water tank. We’ll see.
What still puzzles me is how you manage with a 180L (48 gallons) hot water tank for four people. I would have gone with 270 or 300 liters (71 or 79 gallons) for four people.
Today, I measured the flow rate from my current shower head in my apartment, and it’s about 8 liters per minute (2.1 gallons per minute). I don’t find that to be particularly high, and it’s a standard shower head (far from a rain shower). If you calculate 5 to 10 minutes per person, for the 10-minute case, that’s 80 liters (21 gallons) for the first person. If you set your hot water tank to 45°C (113°F) as you suggested, then about 70 liters (18 gallons) of that 80 liters (21 gallons) for the first person would already be hot water from the tank, right? That doesn’t add up, or are you all just bold enough to take cold showers in the morning?
What still puzzles me is how you manage with a 180L (48 gallons) hot water tank for four people. I would have gone with 270 or 300 liters (71 or 79 gallons) for four people.
Today, I measured the flow rate from my current shower head in my apartment, and it’s about 8 liters per minute (2.1 gallons per minute). I don’t find that to be particularly high, and it’s a standard shower head (far from a rain shower). If you calculate 5 to 10 minutes per person, for the 10-minute case, that’s 80 liters (21 gallons) for the first person. If you set your hot water tank to 45°C (113°F) as you suggested, then about 70 liters (18 gallons) of that 80 liters (21 gallons) for the first person would already be hot water from the tank, right? That doesn’t add up, or are you all just bold enough to take cold showers in the morning?
So, a man doesn’t need 8 minutes, I’d say. I usually take about half that time.
Besides, no woman here starts the whole routine in the morning with washing hair, shaving, and blow-drying. There simply isn’t time for that. They do their washing routines in the evening.
By the way, both find rain showers quite annoying because the cleaning effect on long hair isn’t very good. They use the handheld showerhead or go straight into the bathtub (for shaving legs, etc.).
Besides, no woman here starts the whole routine in the morning with washing hair, shaving, and blow-drying. There simply isn’t time for that. They do their washing routines in the evening.
By the way, both find rain showers quite annoying because the cleaning effect on long hair isn’t very good. They use the handheld showerhead or go straight into the bathtub (for shaving legs, etc.).
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