We are currently in the middle of planning our new build and are now selecting the heating system. We have read that it is now possible to heat using geothermal energy, but we have no experience with it. How exactly does it work, and would you recommend it to us?
What do you mean by "nowadays"? 😉 Ground-source heat pumps have been around for 35 years already...
Your heating system, if properly designed, will still work at your design temperature – if that is -20°C (–4°F) in your area, then it needs to be sized accordingly.
Lex is right, though – the colder your region is (based on actual weather data, not just your assumptions), the less efficient an air-source heat pump will be.
Your heating system, if properly designed, will still work at your design temperature – if that is -20°C (–4°F) in your area, then it needs to be sized accordingly.
Lex is right, though – the colder your region is (based on actual weather data, not just your assumptions), the less efficient an air-source heat pump will be.
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Sebastian7921 Jun 2015 18:03Yep
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ErikErdgas27 Jul 2015 10:23Hello,
Some posts have already discussed the characteristics of heat pumps. Therefore, I want to clearly point out the efficiency of a heat pump, which, to put it diplomatically, is quite modest. It is important to distinguish between air-to-water heat pumps, which have a coefficient of performance (COP) around 3 or lower, and ground-source heat pumps with realistic COPs between 3.3 and 3.8.
To raise the temperature level, the heat pump requires input energy, which is significantly less than the heat energy delivered by the system. This ratio is called the coefficient of performance (COP) or seasonal performance factor (SPF). A seasonal performance factor of 3 means that over the course of a year, the heat pump delivers three times as much heating energy as it consumes in driving energy. Although this initial balance may seem positive, it becomes less favorable when considering that the heat pump is powered by electricity. Since only about one-third of the primary energy used to generate electricity reaches the end consumer, using a heat pump with a COP between 3 and 4 results in a break-even scenario: the loss in the electricity generation process roughly equals the gain from using the heat pump.
To perform better than a gas condensing boiler in an ecological comparison, the COP of the electric heat pump would have to exceed 4, a value that is usually not achieved. Therefore, a heating system based on a heat pump generally has higher CO2 emissions than a good gas heating system. Heat pumps thus require ideal conditions for efficient operation.
The above explanation is meant to show that even your planner, if you have one, will likely be overwhelmed by the complexity of heating system design, planning, and implementation. Therefore, nowadays, even for a single-family house, it is necessary to involve an expert. This can be an energy consultant or a specialist planner for technical building services. Contacts can be found through the Chamber of Engineers, the “Energy Efficiency Experts” portal of DENA, or the German Energy Consultants Network.
Best regards, Erik
Some posts have already discussed the characteristics of heat pumps. Therefore, I want to clearly point out the efficiency of a heat pump, which, to put it diplomatically, is quite modest. It is important to distinguish between air-to-water heat pumps, which have a coefficient of performance (COP) around 3 or lower, and ground-source heat pumps with realistic COPs between 3.3 and 3.8.
To raise the temperature level, the heat pump requires input energy, which is significantly less than the heat energy delivered by the system. This ratio is called the coefficient of performance (COP) or seasonal performance factor (SPF). A seasonal performance factor of 3 means that over the course of a year, the heat pump delivers three times as much heating energy as it consumes in driving energy. Although this initial balance may seem positive, it becomes less favorable when considering that the heat pump is powered by electricity. Since only about one-third of the primary energy used to generate electricity reaches the end consumer, using a heat pump with a COP between 3 and 4 results in a break-even scenario: the loss in the electricity generation process roughly equals the gain from using the heat pump.
To perform better than a gas condensing boiler in an ecological comparison, the COP of the electric heat pump would have to exceed 4, a value that is usually not achieved. Therefore, a heating system based on a heat pump generally has higher CO2 emissions than a good gas heating system. Heat pumps thus require ideal conditions for efficient operation.
The above explanation is meant to show that even your planner, if you have one, will likely be overwhelmed by the complexity of heating system design, planning, and implementation. Therefore, nowadays, even for a single-family house, it is necessary to involve an expert. This can be an energy consultant or a specialist planner for technical building services. Contacts can be found through the Chamber of Engineers, the “Energy Efficiency Experts” portal of DENA, or the German Energy Consultants Network.
Best regards, Erik
ErikErdgas schrieb:
Hello,
Some posts already discuss the characteristics of heat pumps. Therefore, I want to clearly point out the efficiency of a heat pump, which is quite modest, to put it diplomatically. It is important to distinguish between air-to-water heat pumps, which have a coefficient of performance (COP) around 3 or lower, and ground-to-water (brine-to-water) heat pumps, which realistically operate with COPs between 3.3 and 3.8.
To raise the temperature level, the heat pump requires input energy, which is significantly less than the heating energy delivered by the system. This ratio is called the coefficient of performance, often referred to as the seasonal performance factor (SPF). A seasonal performance factor of 3 means the heat pump provides three times as much heating energy annually as the electrical energy it consumes. However, this initially positive balance becomes less favorable when the heat pump is powered by electricity. Because only about one-third of the primary energy used in electricity generation actually reaches the end user, employing a heat pump with a COP between 3 and 4 becomes a break-even scenario: the losses in electricity production roughly equal the gain from using the heat pump.
To perform better in terms of environmental comparison than a modern gas condensing boiler, the COP of an electric heat pump would need to exceed 4, a value that is rarely achieved. Therefore, a heating system with a heat pump generally results in higher CO2 emissions than an efficient gas heating system. Heat pumps require ideal conditions... I have a ground-to-water heat pump and achieved a seasonal performance factor of almost 5 in the last operating year. Other well-designed heat pump systems should be able to reach that as well, especially since my heat pump’s COP is rather average...
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