ᐅ New single-family house construction, gas heating or heat pump, target KfW55 energy efficiency standard
Created on: 15 Aug 2013 20:51
E
Elektrofuzzi
Hello Forum,
I have been reading here for some time and am very impressed by the quality of some of the answers, so I hope to get the right guidance for myself as well.
I am currently planning my single-family house with 171m2 (1840 sq ft) of living space to KfW 70 standard.
Through the developer, I would get a gas condensing boiler with solar hot water and a Zehnder ComfoAir residential ventilation system.
Through a heating installer friend, I could get an Ochsner air-to-water heat pump GMLW9 plus VX with split outdoor unit Millennium MSV 14 for heating,
and an Ochsner Europa 323DK air-to-water heat pump with integrated residential ventilation. This pump would be installed in the utility room and extract warm air from the hallway and bathroom; fresh air would be supplied back to the rooms via membrane flaps on the window.
I would get both options at the same price.
About the house:
Setback floor, 171m2 (1840 sq ft) living space
Underfloor heating with supply temperature approx. 35°C (95°F)
2-layer wall construction: 17.5cm (7 inches) Ytong, 14cm (5.5 inches) insulation, brick veneer
10cm (4 inches) perimeter insulation
Triple glazing, 6-chamber profile, Ug value 0.7
Results of the energy assessment according to DIN 4108-6 and DIN 4701-10
Annual primary energy demand 56.92 kWh/m2
Transmission heat loss 0.27 W/(m2K)
Building envelope area 534.65m2 (5752 sq ft)
Building volume 705.65m2 (7598 sq ft)
Heated air volume 536.29m2 (5772 sq ft)
Usable building area 225.81m2 (2430 sq ft)
A/V ratio 0.76 1/m
Window area 39.36m2 (424 sq ft)
Ground slab U-value 0.23 W/(m2K)
Exterior wall U-value 0.17 W/(m2K)
Wood beam ceiling U-value 0.19 W/(m2K)
Ceiling to outside air above U-value 0.23 W/(m2K)
Ceiling to outside air below U-value 0.22 W/(m2K)
Absolute heating demand 10,704 kWh/year
Absolute hot water demand 2,823 kWh/year
I hope this is enough for now.
My questions:
Which of the above heating systems makes more sense?
Are these values reasonable?
Would I possibly reach KfW 55 with the heat pump system combined with a 5 kWp photovoltaic system?
I look forward to your answers.
Thank you
Elektriker
I have been reading here for some time and am very impressed by the quality of some of the answers, so I hope to get the right guidance for myself as well.
I am currently planning my single-family house with 171m2 (1840 sq ft) of living space to KfW 70 standard.
Through the developer, I would get a gas condensing boiler with solar hot water and a Zehnder ComfoAir residential ventilation system.
Through a heating installer friend, I could get an Ochsner air-to-water heat pump GMLW9 plus VX with split outdoor unit Millennium MSV 14 for heating,
and an Ochsner Europa 323DK air-to-water heat pump with integrated residential ventilation. This pump would be installed in the utility room and extract warm air from the hallway and bathroom; fresh air would be supplied back to the rooms via membrane flaps on the window.
I would get both options at the same price.
About the house:
Setback floor, 171m2 (1840 sq ft) living space
Underfloor heating with supply temperature approx. 35°C (95°F)
2-layer wall construction: 17.5cm (7 inches) Ytong, 14cm (5.5 inches) insulation, brick veneer
10cm (4 inches) perimeter insulation
Triple glazing, 6-chamber profile, Ug value 0.7
Results of the energy assessment according to DIN 4108-6 and DIN 4701-10
Annual primary energy demand 56.92 kWh/m2
Transmission heat loss 0.27 W/(m2K)
Building envelope area 534.65m2 (5752 sq ft)
Building volume 705.65m2 (7598 sq ft)
Heated air volume 536.29m2 (5772 sq ft)
Usable building area 225.81m2 (2430 sq ft)
A/V ratio 0.76 1/m
Window area 39.36m2 (424 sq ft)
Ground slab U-value 0.23 W/(m2K)
Exterior wall U-value 0.17 W/(m2K)
Wood beam ceiling U-value 0.19 W/(m2K)
Ceiling to outside air above U-value 0.23 W/(m2K)
Ceiling to outside air below U-value 0.22 W/(m2K)
Absolute heating demand 10,704 kWh/year
Absolute hot water demand 2,823 kWh/year
I hope this is enough for now.
My questions:
Which of the above heating systems makes more sense?
Are these values reasonable?
Would I possibly reach KfW 55 with the heat pump system combined with a 5 kWp photovoltaic system?
I look forward to your answers.
Thank you
Elektriker
Elektriker schrieb:
...thank you first of all for the reply, unfortunately I am not much wiser than before :-( That is usually the case when essential data, for example from a preliminary assessment, is not known. Elektriker schrieb:
...Two heat pumps for the following reason:... See post by Perlenmann! In addition, such an excessive investment is unlikely to be economically viable. Elektriker schrieb:
...What matters most to us are the costs,... Which costs? Investment or capital service, operating costs, or overall economic efficiency? Elektriker schrieb:
...Which DIN standard must be used for a heating load calculation? DIN 12831 detailed method. If there is a controlled ventilation system, it will be wrong 99.5% of the time ;-). Elektriker schrieb:
...Does that mean the heating installer can’t use the data from the calculation? He can use the geometry of the external building components as well as the U-values. The internal heat transfer coefficient for sizing the heating surfaces and hydraulics must be determined by the installer. Elektriker schrieb:
...The buffer tank ultimately serves as an energy storage for the photovoltaic system and is intended to increase self-consumption. An air source heat pump generates energy at a ratio of approximately 3.5:1, whereas an electric heating element is 1:1 :-) Elektriker schrieb:
...The COP of the heating heat pump is 4.0 at L2/35W according to the manufacturer.
The heating capacity of the domestic hot water heat pump is 2.2 kW at L21/W15-55 according to the manufacturer. Such manufacturer data is as useless as a goiter. The actual annual performance factor (seasonal COP) is what matters. The manufacturer’s performance curves must be evaluated for this! Whether an air source heat pump makes sense for a KfW 70 standard building, only the seller probably knows ;-) best regards
B
Bauexperte16 Aug 2013 11:54Hello,
I have two questions.
2. Do you have your provider’s approval to source the heat generator yourself?
Regards, Bauexperte
I have two questions.
Elektriker schrieb:1. Why do you want to combine radiators with underfloor heating?
I am currently working on the planning of my single-family home with 171m2 (1840 ft2) of living space built to KfW 70 standard.
Through the property developer, I would get a gas condensing boiler with solar hot water and a Zehnder ComfoAir ventilation system.
Through a friend who is a heating installer, I would get an Ochsner air-to-water heat pump GMLW9 plus VX with a split outdoor unit Millennium MSV 14 for heating
and an Ochsner Europa 323DK air-to-water heat pump with integrated residential ventilation. This pump would be installed in the utility room and extracts warm air from the hallway and bathroom, while membrane flaps at the windows supply fresh air back into the rooms.
I get both at the same price.
2. Do you have your provider’s approval to source the heat generator yourself?
Elektriker schrieb:With all due respect – whether or not your heating installer is a friend, I doubt that both options are actually price-neutral. The Ochsner systems are significantly more expensive than comparable units. This price balance would only be possible if your “friend” happens to have these two air-to-water heat pumps in stock due to a wrong purchase and is eager to get rid of them under any circumstances... at least if these are not used devices.
I get both at the same price.
Regards, Bauexperte
E
Elektrofuzzi16 Aug 2013 12:031. Where does it say that I want to combine radiators with underfloor heating? I am only installing underfloor heating.
2. Everything has been coordinated and approved with the building supervisor.
Regarding the price:
Package 1:
Gas condensing boiler with solar system for hot water and standard sanitary fittings (I only have the total price) €26,000
Underfloor heating €5,000
Controlled residential ventilation Zehnder Comfo Air 350 €8,000
Total €39,000
Package 2
Complete, including the same sanitary fittings €40,000
I don’t have the individual prices available right now.
The pump(s) will be newly ordered from the dealer and are not kept in stock.
2. Everything has been coordinated and approved with the building supervisor.
Regarding the price:
Package 1:
Gas condensing boiler with solar system for hot water and standard sanitary fittings (I only have the total price) €26,000
Underfloor heating €5,000
Controlled residential ventilation Zehnder Comfo Air 350 €8,000
Total €39,000
Package 2
Complete, including the same sanitary fittings €40,000
I don’t have the individual prices available right now.
The pump(s) will be newly ordered from the dealer and are not kept in stock.
E
Elektrofuzzi16 Aug 2013 12:26Here are the costs for the heat pump system: 21,500€ including VAT, installation, and engineering services.
Underfloor heating including insulation: 10,000€ including VAT.
Underfloor heating including insulation: 10,000€ including VAT.
M
merlin66717 Aug 2013 12:24Who designed your Ochsner system? Do you have a separation tank included?
I have a quote for the GMLW9 and the outdoor evaporator, 1x domestic hot water buffer tank, and 1x separation tank (needed for the outdoor unit’s regeneration) at just under 20,000 euros. The ventilation unit is an additional cost for me.
I’m not sure if it’s large enough or not, as that depends on your location and specific conditions; therefore, I strongly recommend getting a precise capacity sizing for your heating system. For my 150m² (1,615 sq ft) home with an energy demand of 25 kWh/year/m² heating demand (23 heating demand reference), I come to 6 kW, thanks to my favorable climate, for 6 kW domestic hot water plus heating output. You can find the heat pump’s performance curves online.
Under my conditions, the heat pump still operates monovalently at around -12°C (10°F) – at least on paper.
I combine my heat pump with a 5 kWp photovoltaic system, so I can also cool in the summer (using underfloor heating plus a ventilation unit with a cooling coil), and the electricity then costs me (almost) nothing. In winter, when the heat pump needs electricity the most, you get less from photovoltaics due to lower solar irradiation.
I have a quote for the GMLW9 and the outdoor evaporator, 1x domestic hot water buffer tank, and 1x separation tank (needed for the outdoor unit’s regeneration) at just under 20,000 euros. The ventilation unit is an additional cost for me.
I’m not sure if it’s large enough or not, as that depends on your location and specific conditions; therefore, I strongly recommend getting a precise capacity sizing for your heating system. For my 150m² (1,615 sq ft) home with an energy demand of 25 kWh/year/m² heating demand (23 heating demand reference), I come to 6 kW, thanks to my favorable climate, for 6 kW domestic hot water plus heating output. You can find the heat pump’s performance curves online.
Under my conditions, the heat pump still operates monovalently at around -12°C (10°F) – at least on paper.
I combine my heat pump with a 5 kWp photovoltaic system, so I can also cool in the summer (using underfloor heating plus a ventilation unit with a cooling coil), and the electricity then costs me (almost) nothing. In winter, when the heat pump needs electricity the most, you get less from photovoltaics due to lower solar irradiation.
Hello,
Best regards.
merlin667 schrieb:Where exactly? The performance and COP curves for full modulation are always very interesting!
....The characteristic curves of the heat pump can be found on the internet...
Best regards.
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