Hello, I am currently trying to evaluate the advantages of gas versus electricity.
I’m assuming an annual demand of 5000 kWh including hot water.
What is a realistic seasonal performance factor (SPF) for 2 deep boreholes or for collectors just a few meters underground?
Heat pump costs around €310 for 1500 kWh => SPF 3.3
I have concerns about heat pumps regarding hot water production, as the efficiency is likely to be low when there is a temperature difference of 40-60°C (104-140°F). This is likely to reduce the overall seasonal performance factor, even though the SPF for underfloor heating at 25-30°C (77-86°F) can be above 4.5.
Is anyone’s practical experience available on this?
Gas costs are almost exactly the same at €310.
Purchase costs for gas:
- Gas boiler with solar and hot water 3000-5000 € ?
- Gas connection ? ?
Purchase costs for heat pump:
- Heat pump with hot water storage tank approximately 6000 € ?
- Deep borehole including installation 10,000 € ?
- Or ground collectors ? ?
+ BAFA subsidy 4500 €
Does it make sense to buy a separate air-source heat pump for hot water that is located inside the house and therefore has to heat from approximately 20°C (68°F) to 60°C (140°F)?
Or would it be better to purchase a heat pump with an integrated hot water tank and a solar connection, similar to a gas boiler?
If the operating costs (without photovoltaic system) are roughly the same, I would tend to choose the heat pump, since photovoltaic would allow additional savings in the future.
I’m assuming an annual demand of 5000 kWh including hot water.
What is a realistic seasonal performance factor (SPF) for 2 deep boreholes or for collectors just a few meters underground?
Heat pump costs around €310 for 1500 kWh => SPF 3.3
I have concerns about heat pumps regarding hot water production, as the efficiency is likely to be low when there is a temperature difference of 40-60°C (104-140°F). This is likely to reduce the overall seasonal performance factor, even though the SPF for underfloor heating at 25-30°C (77-86°F) can be above 4.5.
Is anyone’s practical experience available on this?
Gas costs are almost exactly the same at €310.
Purchase costs for gas:
- Gas boiler with solar and hot water 3000-5000 € ?
- Gas connection ? ?
Purchase costs for heat pump:
- Heat pump with hot water storage tank approximately 6000 € ?
- Deep borehole including installation 10,000 € ?
- Or ground collectors ? ?
+ BAFA subsidy 4500 €
Does it make sense to buy a separate air-source heat pump for hot water that is located inside the house and therefore has to heat from approximately 20°C (68°F) to 60°C (140°F)?
Or would it be better to purchase a heat pump with an integrated hot water tank and a solar connection, similar to a gas boiler?
If the operating costs (without photovoltaic system) are roughly the same, I would tend to choose the heat pump, since photovoltaic would allow additional savings in the future.
Sausage or cheese? Ultimately, a matter of personal taste. I think we have a demand of more than 10,000 kWh (10,000 kWh)... also KfW55 standard.
The annual performance factor of modern ground-source heat pumps is generally above 4.5 overall, including domestic hot water. However, the price is also over 600,000 €.
The annual performance factor of modern ground-source heat pumps is generally above 4.5 overall, including domestic hot water. However, the price is also over 600,000 €.
I was just browsing the BAFA list of eligible heat pumps and noticed that there are two types of heat pumps:
- with fixed power output
- with variable power output
The Junkers Supraeco STM 120-2 with variable power output achieves a very high annual performance factor. However, it does not have a connection for solar hot water.
If the average annual performance factor including hot water is 4.5, I clearly tend to prefer the heat pump.
What is the average annual performance factor for ground source collectors?
P.S. In my rented apartment from 2001, two of us consume 7000–8000 kWh of gas including hot water.
I hope to undercut that in the KfW 55 house.
- with fixed power output
- with variable power output
The Junkers Supraeco STM 120-2 with variable power output achieves a very high annual performance factor. However, it does not have a connection for solar hot water.
If the average annual performance factor including hot water is 4.5, I clearly tend to prefer the heat pump.
What is the average annual performance factor for ground source collectors?
P.S. In my rented apartment from 2001, two of us consume 7000–8000 kWh of gas including hot water.
I hope to undercut that in the KfW 55 house.
B
Bauexperte17 May 2016 23:46Becker84 schrieb:
P.S. In my rented apartment from 2001 with gas heating, two of us use about 7000-8000 kWh of gas including hot water.When was it built and according to which energy saving regulation/efficiency house standard?Please be a bit more generous with information.
Best regards, Bauexperte
Keep in mind, your apartment has less exterior wall, roof, and floor slab...
Operating heat pumps with a fixed-speed compressor is generally not recommended.
Modulating heat pumps are advantageous but usually more expensive – you need to consider whether it’s cost-effective.
Properly designed trenches perform almost as well as deep boreholes.
Operating heat pumps with a fixed-speed compressor is generally not recommended.
Modulating heat pumps are advantageous but usually more expensive – you need to consider whether it’s cost-effective.
Properly designed trenches perform almost as well as deep boreholes.
Unfortunately, I have no information about the energy standard of my rental apartment. I strongly suspect it meets the minimum standard required in 2001, judging by how cold my bathroom gets in winter. Otherwise, I can only say it’s 60m² (645 sq ft) spread over the 1st and 2nd floors. Buderus gas condensing boiler with underfloor heating plus standard radiators. Hot water tank is separate.
Why is it discouraged to operate a heat pump together with solar thermal?
A properly installed trench should be much cheaper than a deep borehole, right?
Why is it discouraged to operate a heat pump together with solar thermal?
A properly installed trench should be much cheaper than a deep borehole, right?
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