Hello everyone!
We are currently considering what and how we want to build. It’s about a new build that will be constructed by a developer. At the moment, a 36cm (14 inch) Ytong exterior wall is being offered. I would like to replace the standard heating system—a gas burner with radiators—with a heat pump and underfloor heating throughout the house, completely eliminating the need for a gas connection.
I don’t really want to use an air-source heat pump because I don’t want the noise or the unit in the garden, and I’m not thrilled about the decreasing efficiency during the cold season.
However, I have a few questions about the design and implementation. First, I have no idea how much more expensive ground source heat pumps are compared to air-source heat pumps. Do you have any rough estimates? I would prefer to use ground probes, meaning boreholes, since I consider that the most reliable method.
But what happens if there is damage to the system? A technician can simply open up and repair an air-source heat pump. However, no one would want to dig up the ground probes, right?
Also, how much space is needed for something like this? I was thinking the boreholes could be made in front of the house—that is, between the house and the sidewalk. There’s only about 3–5 meters (10–16 feet) of space there. If someone needs to access the pipes, you would have to remove the paving. I won’t be able to bring in heavy machinery to the garden later on.
To increase the efficiency of the system in the long run, I would also like to add photovoltaic panels later, but that would have to wait a few years due to cost and planning reasons.
Thank you for your help!
We are currently considering what and how we want to build. It’s about a new build that will be constructed by a developer. At the moment, a 36cm (14 inch) Ytong exterior wall is being offered. I would like to replace the standard heating system—a gas burner with radiators—with a heat pump and underfloor heating throughout the house, completely eliminating the need for a gas connection.
I don’t really want to use an air-source heat pump because I don’t want the noise or the unit in the garden, and I’m not thrilled about the decreasing efficiency during the cold season.
However, I have a few questions about the design and implementation. First, I have no idea how much more expensive ground source heat pumps are compared to air-source heat pumps. Do you have any rough estimates? I would prefer to use ground probes, meaning boreholes, since I consider that the most reliable method.
But what happens if there is damage to the system? A technician can simply open up and repair an air-source heat pump. However, no one would want to dig up the ground probes, right?
Also, how much space is needed for something like this? I was thinking the boreholes could be made in front of the house—that is, between the house and the sidewalk. There’s only about 3–5 meters (10–16 feet) of space there. If someone needs to access the pipes, you would have to remove the paving. I won’t be able to bring in heavy machinery to the garden later on.
To increase the efficiency of the system in the long run, I would also like to add photovoltaic panels later, but that would have to wait a few years due to cost and planning reasons.
Thank you for your help!
Shrimp, a heat pump initially sounds environmentally friendly because it uses renewable thermal energy from the environment (air, water, ground, etc.). However, it still requires “high-quality” energy in the form of electricity. Roughly speaking, to produce 1 kWh of electricity, about 3 kWh of heat energy—for example, from coal—needs to be generated.
An air-source heat pump typically has an annual performance factor (coefficient of performance) of about 3 to 3.5. This means it converts 1 kWh of electricity into 3 kWh of heat. In the end, you use roughly the same amount of “primary energy” as if you had directly burned the fossil fuel for heating.
Regarding costs: electricity costs around 20 cents per kWh. Gas costs about 6 cents per kWh. Because of the annual performance factor of 3, you can divide the electricity cost by 3, resulting in approximately 6.6 cents per kWh of thermal energy. So, strictly based on energy consumption, it’s actually more expensive.
What heating output are we actually talking about? How many square meters of living space? What about insulation?
Drilling for 8,500€ is a good price!
An air-source heat pump typically has an annual performance factor (coefficient of performance) of about 3 to 3.5. This means it converts 1 kWh of electricity into 3 kWh of heat. In the end, you use roughly the same amount of “primary energy” as if you had directly burned the fossil fuel for heating.
Regarding costs: electricity costs around 20 cents per kWh. Gas costs about 6 cents per kWh. Because of the annual performance factor of 3, you can divide the electricity cost by 3, resulting in approximately 6.6 cents per kWh of thermal energy. So, strictly based on energy consumption, it’s actually more expensive.
What heating output are we actually talking about? How many square meters of living space? What about insulation?
Drilling for 8,500€ is a good price!
Bauexperte schrieb:
What exactly do you mean by "more money" or "about the same amount" in numbers...?
Regards, Bauexperte For rough estimates, I calculate with 20 cents per kWh electricity, 5-6 cents per kWh gas, an annual performance factor of 3-3.5 for an air-source heat pump, and 4-4.5 for a ground-source heat pump.
If you know your heating energy demand, you can make a quick calculation.
B
Bauexperte21 Jul 2015 22:16Thank you, sir.
It's not enough to just make a simple statement without explaining the background of your reasoning. Even though it has been described countless times here, not every new member manages to work their way through the forums.
Overall, your rough calculation is off because it ignores the construction costs; but you are probably aware of that. I also think that gas condensing boilers will face more challenges starting in 2016 (my personal opinion).
Best regards, Bauexperte
It's not enough to just make a simple statement without explaining the background of your reasoning. Even though it has been described countless times here, not every new member manages to work their way through the forums.
Overall, your rough calculation is off because it ignores the construction costs; but you are probably aware of that. I also think that gas condensing boilers will face more challenges starting in 2016 (my personal opinion).
Best regards, Bauexperte
You are right. Such comparisons can only indicate general trends. In the end, whether the difference amounts to 100, 200, or 300 euros per year is unknown. But at least it shows that there is no huge gap in the operating costs.
When it comes to construction costs, which of course must be considered, the situation can be quite different. However, this depends on various factors: the cost of the gas connection, whether you might want a chimney for a stove anyway, if there is space for flat solar collectors, whether deep drilling is permitted, what design temperature you use (-10 or -16 degrees Celsius (14 or 3 degrees Fahrenheit)), and how well your house is insulated.
A forum can’t really help with this; everyone has to go through it themselves or pay someone to calculate it.
When it comes to construction costs, which of course must be considered, the situation can be quite different. However, this depends on various factors: the cost of the gas connection, whether you might want a chimney for a stove anyway, if there is space for flat solar collectors, whether deep drilling is permitted, what design temperature you use (-10 or -16 degrees Celsius (14 or 3 degrees Fahrenheit)), and how well your house is insulated.
A forum can’t really help with this; everyone has to go through it themselves or pay someone to calculate it.
S
Sebastian7922 Jul 2015 08:49I would recommend that everyone make just one hole and avoid the hassle with multiple drillings—of course, only where this is possible/permitted!
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