ᐅ Air source heat pump with fireplace, hydronic stove, domestic hot water heating
Created on: 26 Jul 2009 15:45
A
atelier-avaA
atelier-ava26 Jul 2009 15:45I have already read through several forums but haven’t found a satisfactory answer. Hopefully, someone here can help me:
We are planning a new build (single-family house, 130m² (1400 ft²)) and are unsure which heating system to choose. Since we plan to mainly heat the ground floor with a fireplace, our idea was to cover the remaining heating demand with an air-source heat pump (due to lower initial costs compared to other heat pump systems). In any case, we want to be independent of gas or oil! You often read that air-source heat pumps are not necessarily the most efficient heating systems, but in our case, it will mostly be used as a backup heating and for hot water supply—or am I mistaken?
Who has experience with the heating system mentioned above and can recommend an air-source heat pump? Or does anyone have an alternative suggestion for an AFFORDABLE heating system?
Thanks for all the answers!
We are planning a new build (single-family house, 130m² (1400 ft²)) and are unsure which heating system to choose. Since we plan to mainly heat the ground floor with a fireplace, our idea was to cover the remaining heating demand with an air-source heat pump (due to lower initial costs compared to other heat pump systems). In any case, we want to be independent of gas or oil! You often read that air-source heat pumps are not necessarily the most efficient heating systems, but in our case, it will mostly be used as a backup heating and for hot water supply—or am I mistaken?
Who has experience with the heating system mentioned above and can recommend an air-source heat pump? Or does anyone have an alternative suggestion for an AFFORDABLE heating system?
Thanks for all the answers!
Ground Source Heat Pump for Single-Family Homes – Yes
Hello,
I work in sales for gas engine heat pumps, so I’m somewhat critical of electric heat pumps. However, they are very well suited for use in single-family homes because they are compact and do not require drilling or other expenses related to any type of probes.
Operation with underfloor heating or a ventilation system is easy and cost-effective. Personally, I prefer units from Mitsubishi Electric.
This allows for domestic hot water supply at around 50 to 55°C (122 to 131°F).
The efficiency aspect is well considered, because when you need heating capacity from outside air, it tends to be cold and only provides a low yield. However, modern refrigeration technology makes it possible to still reach the target temperature.
Regarding independence from oil or gas, this is an illusion. Electricity is produced from oil, gas, and coal. If the prices of these rise, electricity costs will inevitably follow.
It is definitely cost-effective, but when planning, you should ensure that the heat pump can supply the entire building without a fireplace. This means (to be honest) that the heat pump must be slightly oversized (which is unfortunately common) so that the capacity is sufficient even at the lowest outdoor temperatures.
Conclusion: Maintenance and operation are inexpensive; the initial investment is higher than for a condensing boiler; not CO2 neutral (but better than most alternatives); good performance and high efficiency with proper sizing and good connection to low-temperature heating surfaces (underfloor or wall heating). Thanks to inverter operation, light cooling via floor or wall is also possible (although it requires more complex controls).
Hopefully, this helps you.
My subjective opinion: With good insulation in a single-family home, an air-to-ground heat pump is the best choice.
Hello,
I work in sales for gas engine heat pumps, so I’m somewhat critical of electric heat pumps. However, they are very well suited for use in single-family homes because they are compact and do not require drilling or other expenses related to any type of probes.
Operation with underfloor heating or a ventilation system is easy and cost-effective. Personally, I prefer units from Mitsubishi Electric.
This allows for domestic hot water supply at around 50 to 55°C (122 to 131°F).
The efficiency aspect is well considered, because when you need heating capacity from outside air, it tends to be cold and only provides a low yield. However, modern refrigeration technology makes it possible to still reach the target temperature.
Regarding independence from oil or gas, this is an illusion. Electricity is produced from oil, gas, and coal. If the prices of these rise, electricity costs will inevitably follow.
It is definitely cost-effective, but when planning, you should ensure that the heat pump can supply the entire building without a fireplace. This means (to be honest) that the heat pump must be slightly oversized (which is unfortunately common) so that the capacity is sufficient even at the lowest outdoor temperatures.
Conclusion: Maintenance and operation are inexpensive; the initial investment is higher than for a condensing boiler; not CO2 neutral (but better than most alternatives); good performance and high efficiency with proper sizing and good connection to low-temperature heating surfaces (underfloor or wall heating). Thanks to inverter operation, light cooling via floor or wall is also possible (although it requires more complex controls).
Hopefully, this helps you.
My subjective opinion: With good insulation in a single-family home, an air-to-ground heat pump is the best choice.
@Bellyn
Regarding independence from oil or gas, this is an illusion.
Looking at Germany’s gross electricity generation by energy source (2008), mineral oil products account for only 1.6% and natural gas 13%. Both energy sources have passed their peak production and, as finite resources, their prices are expected to rise significantly within 5 to 7 years.
@Atelier-ava
An air-source heat pump with a seasonal performance factor below 3.0 is simply not cost-effective. I would recommend choosing at least one that meets the current BAFA subsidy standards.
Regarding independence from oil or gas, this is an illusion.
Looking at Germany’s gross electricity generation by energy source (2008), mineral oil products account for only 1.6% and natural gas 13%. Both energy sources have passed their peak production and, as finite resources, their prices are expected to rise significantly within 5 to 7 years.
@Atelier-ava
An air-source heat pump with a seasonal performance factor below 3.0 is simply not cost-effective. I would recommend choosing at least one that meets the current BAFA subsidy standards.
parcus schrieb:
@Bellyn
Regarding independence from oil or gas, it is an illusion.
According to the gross electricity generation in Germany by energy sources (2008), mineral oil products account for only 1.6% and natural gas 13%.
Both energy sources are past their peak production and, as finite resources, will see significant price changes within 5–7 years.What else did I say? Electricity will become more expensive; if you don’t generate your own electricity by hand crank, you are not independent from anyone!
According to my research, the share of nuclear energy in Germany is only about 22.1%. If I add your 1.6% from mineral oil and 13% from natural gas, there is still a clear gap to 100% load demand; I have not heard of a 63.3% electricity generation from renewable sources in Germany so far...
Either way: With electricity, you are just as dependent or independent as with oil, gas, coal, or other fuels. No ifs or buts.
Electricity and Seasonal Performance Factor
When people talk about COP instead of the seasonal performance factor, I believe a COP of 3 is possible! There is no air source heat pump with a seasonal performance factor = 3. A geothermal system just barely reaches 3 (when looking at the real numbers and not optimistic estimates).
If the BAFA subsidy is to be used here (which requires a seasonal performance factor of at least 1.2), then I wonder why not all heat pumps are subsidized by now if a seasonal performance factor below 3 is already considered uneconomical.
So make sure to clarify beforehand whether a COP (small epsilon) or the seasonal performance factor is meant.
parcus schrieb:
@Bellyn
@Atelier-ava
An air source heat pump with a seasonal performance factor below 3.0 is simply not cost-effective.
I would try to at least choose one that meets the BAFA subsidy standards.
When people talk about COP instead of the seasonal performance factor, I believe a COP of 3 is possible! There is no air source heat pump with a seasonal performance factor = 3. A geothermal system just barely reaches 3 (when looking at the real numbers and not optimistic estimates).
If the BAFA subsidy is to be used here (which requires a seasonal performance factor of at least 1.2), then I wonder why not all heat pumps are subsidized by now if a seasonal performance factor below 3 is already considered uneconomical.
So make sure to clarify beforehand whether a COP (small epsilon) or the seasonal performance factor is meant.
@Bellyn
The share of renewable energy sources in 2008 was 14.6%.
The political goal is to replace nuclear power with renewable energy sources and thus cover the majority of energy demand through them.
See also the development of renewable energy sources over the past 10 years.
Currently, the aim is to exceed 40%.
---
Starting from 01.07.2009, the calculation of the annual performance factor must be carried out according to VDI 4650 (2009).
The BAFA supports air-to-water heat pumps with a minimum annual performance factor of 3.5 in new buildings and 3.3 in existing buildings, provided that hydraulic balancing of the heating system is verified and the heating curve is adjusted to the respective building.
---
A geothermal system barely achieves a 3 (if you look at the truth and not just the optimistic figures).
That is simply not true. Vertical deep borehole heat pumps currently achieve an annual performance factor of 5.5 to 5.7, and source heat pumps (surface water or ground collectors) reach an annual performance factor of 6.0.
See the heat pump tests by the Interstaatliche Hochschule für Technik Buchs NTB, Switzerland,
or the Austrian Research and Testing Center Arsenal Ges.m.b.H., Vienna,
as well as real-time data from TH Darmstadt on the Bensheim project.
The share of renewable energy sources in 2008 was 14.6%.
The political goal is to replace nuclear power with renewable energy sources and thus cover the majority of energy demand through them.
See also the development of renewable energy sources over the past 10 years.
Currently, the aim is to exceed 40%.
---
Starting from 01.07.2009, the calculation of the annual performance factor must be carried out according to VDI 4650 (2009).
The BAFA supports air-to-water heat pumps with a minimum annual performance factor of 3.5 in new buildings and 3.3 in existing buildings, provided that hydraulic balancing of the heating system is verified and the heating curve is adjusted to the respective building.
---
A geothermal system barely achieves a 3 (if you look at the truth and not just the optimistic figures).
That is simply not true. Vertical deep borehole heat pumps currently achieve an annual performance factor of 5.5 to 5.7, and source heat pumps (surface water or ground collectors) reach an annual performance factor of 6.0.
See the heat pump tests by the Interstaatliche Hochschule für Technik Buchs NTB, Switzerland,
or the Austrian Research and Testing Center Arsenal Ges.m.b.H., Vienna,
as well as real-time data from TH Darmstadt on the Bensheim project.
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