ᐅ Gas with solar thermal? Or heat pump with photovoltaic? Advice needed
Created on: 5 Feb 2020 08:57
M
Micha8589
Good morning to the forum,
I have been researching heating options for quite some time and have gathered a few opinions, which have only made me more uncertain about my decision. That’s why I thought I’d ask the forum.
My family (2 adults, 1 child) is planning to build the following single-family house at the end of this year or beginning of next year:
Single-family home with pitched roof
Approximately 115 m² (1,237 sq ft)
Solid construction (calcium silicate brick ground and upper floors, brick-clad)
No KFW standard
Building location: southern Mecklenburg
Unfortunately, I can’t provide an energy performance certificate or heating load calculation yet, as the preliminary offer is still being prepared. I am also aware that a general statement can’t really be made since every house and heating behavior is individual.
The construction company advised us to install a modern hybrid heating system consisting of a gas condensing boiler and two solar thermal panels on the roof for domestic hot water, as the initial costs are relatively low (plus installation of the central gas connection), and this technology has proven reliable. The entire house is planned to have underfloor heating. According to the company, they have had very positive experiences with this and consider the technology future-proof. (There is also the idea of a fireplace in the living room.)
On the other hand, I think gas prices will not get any cheaper in the future, and the topic of CO₂ taxes (especially concerning the fireplace) worries me somewhat.
In theory, I would prefer to install a geothermal heat pump combined with a suitable photovoltaic system because this would make me independent of fossil fuels and allow me to heat “off-grid” to a certain extent, depending on efficiency. However, I am hesitant because of the very high initial costs and don’t really know how these compare to operational costs. I also can no longer realistically assess which technology offers the best cost-performance ratio (except for air-source heat pumps).
As you can see, I am completely undecided and hope to get some feedback and expertise from the forum.
Thanks in advance for your replies.
I have been researching heating options for quite some time and have gathered a few opinions, which have only made me more uncertain about my decision. That’s why I thought I’d ask the forum.
My family (2 adults, 1 child) is planning to build the following single-family house at the end of this year or beginning of next year:
Single-family home with pitched roof
Approximately 115 m² (1,237 sq ft)
Solid construction (calcium silicate brick ground and upper floors, brick-clad)
No KFW standard
Building location: southern Mecklenburg
Unfortunately, I can’t provide an energy performance certificate or heating load calculation yet, as the preliminary offer is still being prepared. I am also aware that a general statement can’t really be made since every house and heating behavior is individual.
The construction company advised us to install a modern hybrid heating system consisting of a gas condensing boiler and two solar thermal panels on the roof for domestic hot water, as the initial costs are relatively low (plus installation of the central gas connection), and this technology has proven reliable. The entire house is planned to have underfloor heating. According to the company, they have had very positive experiences with this and consider the technology future-proof. (There is also the idea of a fireplace in the living room.)
On the other hand, I think gas prices will not get any cheaper in the future, and the topic of CO₂ taxes (especially concerning the fireplace) worries me somewhat.
In theory, I would prefer to install a geothermal heat pump combined with a suitable photovoltaic system because this would make me independent of fossil fuels and allow me to heat “off-grid” to a certain extent, depending on efficiency. However, I am hesitant because of the very high initial costs and don’t really know how these compare to operational costs. I also can no longer realistically assess which technology offers the best cost-performance ratio (except for air-source heat pumps).
As you can see, I am completely undecided and hope to get some feedback and expertise from the forum.
Thanks in advance for your replies.
I just want to say that when doing a realistic cost-effectiveness comparison, you have to compare Junkers with Junkers, Viessmann with Viessmann, or similar brands. Not a no-name, pressured-sale system on a plot of land compared to branded equipment from Buderus or the like. And also not a DIY setup compared with professional installation. In 2018, we had a new Viessmann system installed in a house, including a new exhaust pipe. The total cost with taxes was 5,500 (all inclusive).
I completely agree with Nordlys on this... for example, we also chose a gas boiler despite our strong interest in technology and a house full of electronics. Some of the reasons are partly explained in my first post in this thread.
The boiler has been running smoothly for almost 10 years, doing exactly what it’s supposed to at reasonable operating and maintenance costs. We like to keep around 24°C (75°F) not only in the bathroom but in all living areas; only the bedrooms are kept at about 20°C (68°F), and that would already kill the efficiency of any heat pump.
Additionally, the initial investment cost during construction was less than half compared to the cheapest heat pump offered by the general contractor.
That said, I do have a heat pump for cooling in the summer.
In terms of complexity, heat pumps and gas boilers are quite similar. Neither is rocket science. Both can be maintained and repaired more or less easily, and you need the appropriate qualification or certification to work on either system.
The difference is that with gas boilers, you could almost say you can hit them with a hammer and nothing will happen... but with a heat pump, every little thing and every not 100% optimal setting can be associated with significant extra costs.
By the way, despite all the bad news, the gas price has remained mostly stable over this period. Even back in 2010, the pessimists predicted enormous price increases and so on...
In contrast, electricity prices have steadily risen and basically only know one direction:
The boiler has been running smoothly for almost 10 years, doing exactly what it’s supposed to at reasonable operating and maintenance costs. We like to keep around 24°C (75°F) not only in the bathroom but in all living areas; only the bedrooms are kept at about 20°C (68°F), and that would already kill the efficiency of any heat pump.
Additionally, the initial investment cost during construction was less than half compared to the cheapest heat pump offered by the general contractor.
That said, I do have a heat pump for cooling in the summer.
In terms of complexity, heat pumps and gas boilers are quite similar. Neither is rocket science. Both can be maintained and repaired more or less easily, and you need the appropriate qualification or certification to work on either system.
The difference is that with gas boilers, you could almost say you can hit them with a hammer and nothing will happen... but with a heat pump, every little thing and every not 100% optimal setting can be associated with significant extra costs.
By the way, despite all the bad news, the gas price has remained mostly stable over this period. Even back in 2010, the pessimists predicted enormous price increases and so on...
In contrast, electricity prices have steadily risen and basically only know one direction:
T
T_im_Norden9 Feb 2020 14:11It is installed to use the warm wastewater from the shower to preheat the incoming water in the shower. It should provide some savings.
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