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Hausbauer118 Jun 2017 19:22Hello everyone,
It’s not that simple. In new construction, you often encounter air-to-water heat pumps, as this is probably the easiest and most cost-effective way to comply with current legal requirements.
However, I wonder if this is really the best (most economical) option. You often read about quite high electricity costs caused by air-to-water heat pumps. I believe a conventional gas or oil heating system alone is no longer permitted under current regulations, even though it is probably significantly cheaper in itself.
Air-to-air heat pumps seem to be rather impractical—very expensive to operate due to their low efficiency. Then there are options like water-to-water heat pumps (geothermal, groundwater, brine). These tend to have very high upfront costs, and the electricity expenses don’t seem negligible either.
Is there anyone here who can share their own experience regarding satisfaction with the different options? Or can someone provide a theoretical comparison of the pros and cons? In the end, the question for most of us is probably which option is the most economical, since nobody likes to waste money.
Best regards,
HB1
It’s not that simple. In new construction, you often encounter air-to-water heat pumps, as this is probably the easiest and most cost-effective way to comply with current legal requirements.
However, I wonder if this is really the best (most economical) option. You often read about quite high electricity costs caused by air-to-water heat pumps. I believe a conventional gas or oil heating system alone is no longer permitted under current regulations, even though it is probably significantly cheaper in itself.
Air-to-air heat pumps seem to be rather impractical—very expensive to operate due to their low efficiency. Then there are options like water-to-water heat pumps (geothermal, groundwater, brine). These tend to have very high upfront costs, and the electricity expenses don’t seem negligible either.
Is there anyone here who can share their own experience regarding satisfaction with the different options? Or can someone provide a theoretical comparison of the pros and cons? In the end, the question for most of us is probably which option is the most economical, since nobody likes to waste money.
Best regards,
HB1
Oh, these are matters of personal preference. I prefer gas heating, while Alex is more in favor of heat pumps...
The fact is, the energy saving regulations don’t specify which system you have to use, but they do require you to incorporate a certain share of renewable energy or alternatively use district heating generated from renewable sources. Since district heating is quite rare in Germany, the question of heating systems comes into play. Gas is only viable with solar panels for domestic hot water or in combination with a heat recovery ventilation system. The first option is cheaper, actually the cheapest. However, the gas connection fee must be paid. Here it’s around 1500, elsewhere often 1000 more.
Pellet heating is also considered renewable, but it requires storage space for pellets, so it is mainly practical in rural areas where land is more affordable and it is well accepted.
Geothermal and similar systems are expensive but efficient solutions. I don’t believe they will ever economically outperform gas. That leaves the air-to-water heat pump. It’s affordable, uses renewable energy—air, that is—requires no gas connection, and has been in production for many years now, so it’s no longer a niche product. A compressor draws outside air into a heat exchanger, extracting heat from it to warm water. That’s the basic principle.
The downside of this system is electricity consumption. The compressor always uses power, and in winter, when heat demand is highest, the air often needs to be preheated with an electric heating element; otherwise, there’s little heat to extract. In addition to electricity costs, such a heat pump requires underfloor heating, since the supply temperature must be kept as low as possible. Whether these systems are economically able to beat gas is debatable. It depends on the price of gas and electricity. I hope I have been mostly objective. Karsten
The fact is, the energy saving regulations don’t specify which system you have to use, but they do require you to incorporate a certain share of renewable energy or alternatively use district heating generated from renewable sources. Since district heating is quite rare in Germany, the question of heating systems comes into play. Gas is only viable with solar panels for domestic hot water or in combination with a heat recovery ventilation system. The first option is cheaper, actually the cheapest. However, the gas connection fee must be paid. Here it’s around 1500, elsewhere often 1000 more.
Pellet heating is also considered renewable, but it requires storage space for pellets, so it is mainly practical in rural areas where land is more affordable and it is well accepted.
Geothermal and similar systems are expensive but efficient solutions. I don’t believe they will ever economically outperform gas. That leaves the air-to-water heat pump. It’s affordable, uses renewable energy—air, that is—requires no gas connection, and has been in production for many years now, so it’s no longer a niche product. A compressor draws outside air into a heat exchanger, extracting heat from it to warm water. That’s the basic principle.
The downside of this system is electricity consumption. The compressor always uses power, and in winter, when heat demand is highest, the air often needs to be preheated with an electric heating element; otherwise, there’s little heat to extract. In addition to electricity costs, such a heat pump requires underfloor heating, since the supply temperature must be kept as low as possible. Whether these systems are economically able to beat gas is debatable. It depends on the price of gas and electricity. I hope I have been mostly objective. Karsten
Yes, you were. Glad to hear that. However, it’s not entirely true that an air-to-water heat pump always needs the electric heating element at low temperatures. There are models that perform well even in cold conditions.
The biggest issue with heat pumps is that heating engineers often lack experience, which leads to poor hydraulic design and settings. This is often the reason for high electricity costs.
When properly sized and configured, it is easy to achieve an air-to-water heat pump efficiency of 3.5 to 4 kWh of heating energy from 1 kWh of electricity.
Gas systems are well-established and require less attention.
Both have their advantages.
The biggest issue with heat pumps is that heating engineers often lack experience, which leads to poor hydraulic design and settings. This is often the reason for high electricity costs.
When properly sized and configured, it is easy to achieve an air-to-water heat pump efficiency of 3.5 to 4 kWh of heating energy from 1 kWh of electricity.
Gas systems are well-established and require less attention.
Both have their advantages.
You can also consider district heating if it is available in your area.
Air-to-water heat pumps are not necessarily big electricity consumers. When properly adjusted, they run quietly and efficiently. The electric heating element in many pumps only activates at temperatures around -15°C (5°F). I can hardly remember a winter in our region being that cold.
Air-to-water heat pumps are not necessarily big electricity consumers. When properly adjusted, they run quietly and efficiently. The electric heating element in many pumps only activates at temperatures around -15°C (5°F). I can hardly remember a winter in our region being that cold.
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Bieber081519 Jun 2017 09:29Hausbauer1 schrieb:
Is there anyone here who can share personal experience regarding satisfaction with the different options? We purchased from a developer, so the options to influence or optimize the heating system were quite limited. Under these conditions, the air-to-water heat pump was by far the most cost-effective option for us. A gas condensing boiler would have resulted in a higher initial purchase price. However, that may not always be the case. Gas would have been my preferred choice...
In the first year, we achieved a coefficient of performance (COP) of just over 3, with heating electricity costs (heating and hot water) of just under 1000 euros* for orientation purposes (as a rough figure; I don’t want to go into further detail here regarding heating habits, shower frequency, number of occupants, a long winter, etc.).
*Note: The euro figure is actually quite misleading because more than 50% consists of taxes and fees. But in the end, it’s euros that matter, not kWh.
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Hausbauer129 Jun 2017 15:07I recently received the following information from the general contractor: A ground source heat pump costs 10,000 euros more than an air-to-water heat pump. However, there is a subsidy, so the price difference is "only" 5,000 to 6,000 euros. In return, the ground source heat pump saves about 40 euros in electricity costs per month compared to the air-to-water heat pump.
And to be honest, if that is true, I wouldn’t have to think twice and would go for the ground source heat pump. But is that really accurate?
And to be honest, if that is true, I wouldn’t have to think twice and would go for the ground source heat pump. But is that really accurate?
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