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.
T
T_im_Norden20 May 2020 09:12Heat pumps versus gas heating, when considering only costs, always depend on personal expectations regarding the development of energy prices.
The initial installation costs are now relatively comparable due to significant subsidies, although it seems that heat pump prices are rising in proportion to the subsidies.
Another aspect is the replacement cost if the system breaks down. Without subsidies, a heat pump can become quite expensive.
The initial installation costs are now relatively comparable due to significant subsidies, although it seems that heat pump prices are rising in proportion to the subsidies.
Another aspect is the replacement cost if the system breaks down. Without subsidies, a heat pump can become quite expensive.
S
Strahleman20 May 2020 09:12AleXSR700 schrieb:
How exactly do you fully "empty" the storage tank? This is not about emptying the water storage tank entirely. The drinking water stored in it should be completely replaced within 2-3 days, meaning if you have a 300-liter (79 gallons) tank, you should have withdrawn 300 liters (79 gallons) from the tank after 3 days. This prevents the growth of Legionella bacteria. In a single-family home, Legionella hardly ever occurs if water is regularly drawn. And as mentioned before, a fresh water station provides a solution if you are still worried about it.
AleXSR700 schrieb:
I also see heat pumps increasingly in all new apartment buildings, where to my knowledge the minimum temperature is legally defined and usually no photovoltaic systems exist. This seems very disadvantageous for tenants to me. But that is a different issue. Here we are talking about a single-family house, not a multi-family building. So it’s not comparable.
AleXSR700 schrieb:
I don’t want to speak badly of heat pumps either; I’m just trying to assess them realistically for myself. Without a sufficiently sized photovoltaic system, they seem rather unprofitable and possibly not truly environmentally friendly. Then you should also take the time to study the topic of ground-source heat pumps yourself. That can take several evenings. Asking about it generally in the forum is not very effective since every house is different and comes with different conditions. In our planned house, a heat pump is extremely cost-effective. We don’t have a gas connection, and I definitely don’t want a tank in the basement. Additionally, I was able to install the ground collectors myself. Because we are installing a controlled mechanical ventilation with heat recovery, we now receive a 35% subsidy on the entire system. Price-wise, we are now even below the cost of a gas boiler.
And you can get 100% green electricity. It may be true that due to the grid it’s not always fully green, but the energy you consume is definitely offset by renewable energy fed into the grid.
And what is environmentally unfriendly about that? Ideally, you turn 1 kWh of electricity into 5 kWh of heat.
A
AleXSR70020 May 2020 11:20Strahleman schrieb:
This is not about emptying the water storage tank. The drinking water stored inside should be completely replaced every 2-3 days, meaning if you have a 300-liter (79-gallon) tank, you should have drawn all 300 liters (79 gallons) from the tank within 3 days. This prevents the growth of Legionella bacteria. In a single-family home, Legionella hardly ever occurs anyway, as long as water is regularly used. And as I said, a fresh water station can help if you are still worried about it. Well, as I said: if you don’t stop the inflow of fresh water, you will never actually empty the tank but only keep diluting it. This is what most reasonably planned households do anyway, yet Legionella still develop because you can’t fully empty such a tank.
So this approach doesn’t really help. It’s reassuring but if you ever get Legionella, you definitely won’t get rid of them that way. And since you’re always within the "risk" temperature range, you can never be certain and would actually need to test continuously.
So, as mentioned, drawing 100 liters (26 gallons) of hot water per day is not equivalent to emptying the tank over 3 days. Especially since 100 liters (26 gallons) is probably not drawn all at once. One person showers in the morning, another in the evening. Water is used at different times. Realistically, you might use 50 liters (13 gallons) and leave 250 liters (66 gallons) in the tank. The fresh 50 liters (13 gallons) dilute and lower the concentration of Legionella (number per liter), but bacteria continue to multiply. In fact, if you proceed this way, this approach essentially achieves nothing.
Strahleman schrieb:
And the electricity you get is 100% green energy. It may not be fully true because of the power grid, but the energy you consume is definitely fed into the grid from renewable sources. That is not quite correct.
By paying extra, you support renewable energy investments. In other words, you help fund new projects. That’s all. If everyone suddenly consumed more electricity by switching to electric heating, the demand would far exceed the current renewable energy production, even if everyone paid for green energy. Renewable energy sources in Germany do not cover the entire market, so green electricity is not really green electricity as you describe it here.
Also, it must be remembered that the best thing for the environment is not to consume more green electricity, but to reduce overall electricity usage.
In principle, the calculation of "1 kWh of electricity ideally produces 5 kWh of heat" sounds good, but you must also consider the efficiency of electricity generation, which is not 100%. You would need to compare how many kWh of heat you can produce from electricity including its generation versus gas.
Again, I don’t know the exact numbers, but these "up to" calculations remind me of my landlord and his architect. At the end of the day, it cost a fortune, and the consumer was left with the short end of the stick. And whether the huge electricity consumption was ultimately better for the environment than gas or district heating remains unclear at this point.
S
Strahleman20 May 2020 12:08AleXSR700 schrieb:
Well, as I said: If you don’t prevent the backflow of fresh water, you’ll never empty the storage tank but only keep diluting it. Exactly, that’s what I meant by “exchange.” I never said empty. This exchange at temperatures between 45-50 °C (113-122 °F) is now common practice with heat pumps and is done like this in many thousands of households. There are certainly different opinions and many discussions on this topic. If you consider this approach too risky, then you should also omit circulation. Studies have shown that single-family homes with circulation had significantly more Legionella in the water than those without circulation. So, you can expand this topic in many directions. That’s why I mentioned the fresh water station, as it is the most hygienic solution at low temperatures (drinking water is only heated when needed).
AleXSR700 schrieb:
That’s not quite correct.
With your additional charge, you actually promote renewable energy. In other words, you encourage investments. Then take a look at providers like Naturstrom, not just the big ones like E.ON and others. Naturstrom sources 100% of their electricity from wind and hydropower plants in Germany. Of course, subsidies exist, but they are provided anyway through the Renewable Energy Act surcharge (at least theoretically).
AleXSR700 schrieb:
One should not forget: the best thing for the environment is not to consume more green electricity, but to reduce overall electricity consumption. I completely agree. But I’d rather use 1 kWh of green electricity (and pay my extra for renewable energy) from a renewable source than produce the same heat with gas. That also needs to be supported (fracking comes to mind).
AleXSR700 schrieb:
In principle, the calculation of “1 kWh electricity ideally equals 5 kWh heat” is fine, but you also need to consider the efficiency of electricity generation. It’s not 100%. You’d have to compare how much kWh of heat you can produce from electricity including its production versus from gas. I’ve noticed you enjoy debating a lot here in the forum (see, for example, the KNX thread). But at some point, you have to draw the line between meaningful discussion and arguing for the sake of arguing. The sun doesn’t care whether a photovoltaic panel has 7, 15, or 25% efficiency since it taps into a renewable energy source. Okay, photovoltaics also require energy to manufacture, so they’re less favorable in that aspect. So, as you can see, this game can be played endlessly, scrutinizing every detail to the last degree.
A
AleXSR70020 May 2020 12:57I’m not trying to argue just for the sake of arguing, but rather to question everything before committing to something that might turn out to be a dead end, resulting in a building or purchase you could regret in 10 years. This is especially important when there are currently substantial subsidies involved. These often make products appear cheap now, but they can end up being very costly over the next 10 to 30 years.
That’s why it’s better to understand now how a KNX system should be structured and what versions exist. It’s also better to understand the advantages and risks of a heat pump from the start.
To be honest, in our rental apartment, hot water is produced entirely by electricity, and although it is expensive, I find the concept very interesting. Because electricity will be produced more sustainably in the long term, and once battery technology becomes more affordable and durable, photovoltaic systems will become increasingly relevant for house construction.
That’s why I also believe: the more I can operate using electricity, the better. As long as I have a sufficiently powerful photovoltaic system and preferably a feed-in system with batteries.
But you need to carefully examine what is ultimately the most efficient and what you plan to build. If, like with geothermal energy in the past, you bet on the seemingly right solution at the wrong time and with the wrong execution, you’ll still be the one in 15 years with high investment plus high operating costs.
That’s why I always enjoy discussing these topics—especially with people who have more experience or knowledge on the subject. This way, you can precisely find out what is really good and what isn’t.
That’s why it’s better to understand now how a KNX system should be structured and what versions exist. It’s also better to understand the advantages and risks of a heat pump from the start.
To be honest, in our rental apartment, hot water is produced entirely by electricity, and although it is expensive, I find the concept very interesting. Because electricity will be produced more sustainably in the long term, and once battery technology becomes more affordable and durable, photovoltaic systems will become increasingly relevant for house construction.
That’s why I also believe: the more I can operate using electricity, the better. As long as I have a sufficiently powerful photovoltaic system and preferably a feed-in system with batteries.
But you need to carefully examine what is ultimately the most efficient and what you plan to build. If, like with geothermal energy in the past, you bet on the seemingly right solution at the wrong time and with the wrong execution, you’ll still be the one in 15 years with high investment plus high operating costs.
That’s why I always enjoy discussing these topics—especially with people who have more experience or knowledge on the subject. This way, you can precisely find out what is really good and what isn’t.
S
Strahleman20 May 2020 13:27AleXSR700 schrieb:
They often make products seem cheap now, but they end up costing a lot more in 10-30 years. Within that time frame, you will probably have to replace your heating system at least once, whether it’s a heat pump or a gas boiler. As long as you can keep using the heating pipes (for example, underfloor heating), switching to a different heating source is even possible. Therefore, I would focus now on what makes sense for heating in the future—for example, you wouldn’t want to install wall-mounted radiators that require high flow temperatures these days.
AleXSR700 schrieb:
Honestly, in our rental apartment, the hot water is produced entirely electrically, and although it’s expensive, I find the concept very interesting. That is not a disqualifier even for a heat pump. For instance, you can use an electric heating element in the heat pump or in the domestic hot water tank for additional heating. Direct electric heating at the taps via fully electronic instantaneous water heaters is also an option. Domestic hot water heating does not necessarily have to run through the heat pump or gas boiler. Furthermore, modern heat pumps have interfaces for direct photovoltaic integration. In summer, for example, this can be used to operate passive cooling functionality in the heat pump.
AleXSR700 schrieb:
If, like back when geothermal was popular, you bet on the pseudo-right solution at the wrong time with poor execution, in 15 years you’ll still be the fool who had high upfront and high operating costs. Try searching for the “heat pump consumption database” and look for ground-source heat pumps in your area. This will give you an idea of the annual electricity input and how much heat energy is generated. These are quite good indicators of what the average operating costs might be.
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