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 15:11annab377 schrieb:
@Strahleman that was definitely not meant as an attack or criticism Sorry, I didn’t see your reply earlier. No worries, I didn’t take it as an attack.
I wasn’t referring to a buffer tank for the heating circuit, but rather a storage tank for the domestic hot water. The hot domestic water needs to be stored somehow. There are different types, such as hygienic storage tanks, domestic hot water tanks with heat exchangers, or stratified tanks. The latter is great for a fresh water station because the hottest water is always stored at the top, and the colder water is layered at the bottom.
I wouldn’t install a buffer tank in the heating circuit anymore either.
Thank you, but I still don’t fully understand something. Isn’t the temperature in the upper warm layer of a stratified tank significantly higher than in a “regular hot water tank” (over 60°C (140°F), so no legionella risk, right)? And isn’t that much more demanding for the heat pump than heating a 180-liter (48-gallon) hot water tank to, say, 45°C (113°F)? That’s why I thought stratified tanks are mainly used with gas heating systems or solar thermal systems, not with heat pumps.
But it sounds interesting. How much higher would you estimate the investment costs are for a stratified tank plus a fresh water station compared to a “regular” hot water tank of 180 or 270 liters (48 or 71 gallons)?
Does Nibe have a specific model that is especially suitable for a stratified tank, or are all NIBE brine-to-water heat pumps generally compatible?
How many liters does your stratified tank hold in total, and what are the temperature and volume per layer?
But it sounds interesting. How much higher would you estimate the investment costs are for a stratified tank plus a fresh water station compared to a “regular” hot water tank of 180 or 270 liters (48 or 71 gallons)?
Does Nibe have a specific model that is especially suitable for a stratified tank, or are all NIBE brine-to-water heat pumps generally compatible?
How many liters does your stratified tank hold in total, and what are the temperature and volume per layer?
To ensure proper water hygiene, there are different approaches.
Keeping the hot water at a high temperature means higher heat loss and increased energy consumption, especially with a heat pump.
Maintaining hot water at a lower temperature requires choosing a storage tank small enough so that the water is safely used up daily.
Storage systems with fresh water production generate hot water on demand. The water in the tank is typically about 5°C (9°F) warmer than the desired hot water temperature.
Personally, I find this solution the best, although it is also the most expensive.
Keeping the hot water at a high temperature means higher heat loss and increased energy consumption, especially with a heat pump.
Maintaining hot water at a lower temperature requires choosing a storage tank small enough so that the water is safely used up daily.
Storage systems with fresh water production generate hot water on demand. The water in the tank is typically about 5°C (9°F) warmer than the desired hot water temperature.
Personally, I find this solution the best, although it is also the most expensive.
S
Strahleman10 May 2020 18:25The temperature in the stratified storage tank depends on your settings. Here, too, you can set the target temperature to, for example, 45°C (113°F).
A stratified tank usually includes baffles, stratification pipes, or flow calming returns to optimize temperature layering inside the tank. When charging the tank, it is important that the hot water does not enter at a high flow rate but at a low flow rate, allowing the water to layer without mixing. This can be achieved quite well with a Nibe S1155 (or 1255), as the flow rate is very low (290 liters per hour). With this model, stratification would likely work well even with an empty hot water tank. For a potable water station, however, the return flow should be calmed, for example with deflectors. Otherwise, stratification could be impaired, since the return flow can be as high as 25 liters per minute (1,500 liters per hour) when multiple appliances are running simultaneously.
Regarding temperature, due to losses in the heat exchanger of the potable water station, you need to store the hot water about 3-5 K (5-9°F) warmer to achieve your desired temperature. This method is very hygienic and leaves almost no chance for Legionella bacteria to develop.
A stratified tank usually includes baffles, stratification pipes, or flow calming returns to optimize temperature layering inside the tank. When charging the tank, it is important that the hot water does not enter at a high flow rate but at a low flow rate, allowing the water to layer without mixing. This can be achieved quite well with a Nibe S1155 (or 1255), as the flow rate is very low (290 liters per hour). With this model, stratification would likely work well even with an empty hot water tank. For a potable water station, however, the return flow should be calmed, for example with deflectors. Otherwise, stratification could be impaired, since the return flow can be as high as 25 liters per minute (1,500 liters per hour) when multiple appliances are running simultaneously.
Regarding temperature, due to losses in the heat exchanger of the potable water station, you need to store the hot water about 3-5 K (5-9°F) warmer to achieve your desired temperature. This method is very hygienic and leaves almost no chance for Legionella bacteria to develop.
guckuck2 schrieb:
Of course, you can more or less empty 180 liters (47 gallons) with a hot bath. If you want to use the rain shower immediately afterwards, it might be tight. However, in everyday use, we haven’t experienced any limitations yet.
The advantage is hygiene, as there is a high water turnover in the tank. Additionally, this benefits the efficiency of the heat pump. How long does it actually take for the heat pump to "refill" 90 liters (24 gallons) after the 180-liter (47-gallon) storage tank has been half emptied? Does it depend on the heat pump settings, photovoltaic power availability, etc., or does the heat pump usually start heating new cold water immediately and make it available again in the tank?
A domestic hot water storage tank with integrated heat exchanger sounds good, but it also means additional costs and possibly higher maintenance, right?
That’s why I’m asking how quickly it works with a half-empty 180-liter (47-gallon) tank or any other size. Thanks.
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