ᐅ Final House Planning: Heating Components, What Makes Sense – No Air Source Heat Pump
Created on: 10 Feb 2016 10:37
V
Veltins
Hello everyone,
After spending the past few weeks figuring out what, how, with whom, and how big we want to build, we are now focusing on what I consider almost the most important part: choosing the right technology, especially the heating and cooling systems. We are planning a 144 sqm (1550 sq ft) house built to KfW 40 standard. It will have no basement, located in a low-altitude area in NRW, and will house four people.
Our general contractor (GC) typically installs the following components:
- Nibe Fighter 755 G air-source heat pump (variant of the 750 model) combined with a solar panel system with 2 kWp output
- Underfloor heating on the ground and upper floors
- 180-liter (48-gallon) domestic hot water tank
Optionally, the following components can be installed at an additional cost:
- Expansion of the photovoltaic system to 3.3 kWp
- 7.0 kWh home battery
- Inverter
Our requests regarding heating capacity and expected electricity consumption have yielded rather unsatisfactory results. In other words: too much marketing talk and too few answers to ease my concerns, which are as follows:
- Is the Nibe 755 G with the small solar panel, despite good insulation, even sufficiently sized to handle 144 sqm (1550 sq ft) without continuous supplemental heating? Are 180 liters (48 gallons) really enough, especially with two small children? And does it make sense to invest a five-figure amount in expanding the photovoltaic system with a battery relative to the cost?
- Is an optional stove worth it at all? With around 7,000 EUR for the chimney plus the stove itself, economically, it doesn’t add up. We are almost ruling it out.
- What other “combinations” besides an air-source heat pump would you consider?
Basically, I am not opposed to an air-source heat pump, but if a projected annual need of 6,000 kWh for hot water and heating is the standard for this setup, then I currently achieve comparable costs with my existing 1990 house that has poor insulation and a gas boiler. You can guess which GC we are dealing with. Replacing the standard components is not easy.
I am about to consult a heating expert, as I really don’t trust the GC on this point, and they mostly just hire their standard suppliers to install standard equipment. Therefore, I would be very grateful for any expert tips on this topic in advance.
Best regards
After spending the past few weeks figuring out what, how, with whom, and how big we want to build, we are now focusing on what I consider almost the most important part: choosing the right technology, especially the heating and cooling systems. We are planning a 144 sqm (1550 sq ft) house built to KfW 40 standard. It will have no basement, located in a low-altitude area in NRW, and will house four people.
Our general contractor (GC) typically installs the following components:
- Nibe Fighter 755 G air-source heat pump (variant of the 750 model) combined with a solar panel system with 2 kWp output
- Underfloor heating on the ground and upper floors
- 180-liter (48-gallon) domestic hot water tank
Optionally, the following components can be installed at an additional cost:
- Expansion of the photovoltaic system to 3.3 kWp
- 7.0 kWh home battery
- Inverter
Our requests regarding heating capacity and expected electricity consumption have yielded rather unsatisfactory results. In other words: too much marketing talk and too few answers to ease my concerns, which are as follows:
- Is the Nibe 755 G with the small solar panel, despite good insulation, even sufficiently sized to handle 144 sqm (1550 sq ft) without continuous supplemental heating? Are 180 liters (48 gallons) really enough, especially with two small children? And does it make sense to invest a five-figure amount in expanding the photovoltaic system with a battery relative to the cost?
- Is an optional stove worth it at all? With around 7,000 EUR for the chimney plus the stove itself, economically, it doesn’t add up. We are almost ruling it out.
- What other “combinations” besides an air-source heat pump would you consider?
Basically, I am not opposed to an air-source heat pump, but if a projected annual need of 6,000 kWh for hot water and heating is the standard for this setup, then I currently achieve comparable costs with my existing 1990 house that has poor insulation and a gas boiler. You can guess which GC we are dealing with. Replacing the standard components is not easy.
I am about to consult a heating expert, as I really don’t trust the GC on this point, and they mostly just hire their standard suppliers to install standard equipment. Therefore, I would be very grateful for any expert tips on this topic in advance.
Best regards
I made it very clear to "my" sales representative that I will not sign any contract without a reliable heating load calculation, especially since so many inaccurate values are circulating online. A calculation based on 19°C (66°F) room temperature doesn’t help me if it completely ignores my needs with small children. I’m curious to see, as the sales rep is taking a financial risk upfront. As I said, nothing is signed yet.
Are there any additional experiences with the Nibe air-to-water heat pump in combination?
There is also another issue with the photovoltaic system: Our preferred plot would have a roughly east-west gable roof situation with a 45° (45°) roof pitch. Not exactly ideal for a photovoltaic system, right? One row of houses over, the gable orientation reverses and there the roof has an almost perfect south-facing alignment. But that comes with other disadvantages. Such a tricky topic overall!
Are there any additional experiences with the Nibe air-to-water heat pump in combination?
There is also another issue with the photovoltaic system: Our preferred plot would have a roughly east-west gable roof situation with a 45° (45°) roof pitch. Not exactly ideal for a photovoltaic system, right? One row of houses over, the gable orientation reverses and there the roof has an almost perfect south-facing alignment. But that comes with other disadvantages. Such a tricky topic overall!
B
Bauexperte15 Feb 2016 16:10Veltins schrieb:
I made it quite clear to "my" sales representative Then I’m curious if he will deliver.
Veltins schrieb:
There is an additional problem with the photovoltaic system: Our preferred plot would have a fairly typical east-west gable roof with a 45-degree roof pitch. Not really ideal for the photovoltaic system, right? Don’t let anyone convince you otherwise; east-west orientation is fine!
What I think is less ideal is when house purchase + photovoltaic system including battery come from the same provider. We don’t do that because photovoltaic technology is just as complex as house construction. In this area, we work with a specialist company that spends all day focusing exclusively on this topic. For me, it’s enough to do my own job well.
Best regards, Bauexperte
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