ᐅ Alternatives to Outdoor Installation of an Air Source Heat Pump

Created on: 12 Jan 2022 17:45
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ConnyJash
Hello dear house building forum,

We are building a KFW55 semi-detached house with approximately 150m² (1,615 sq ft) of living space. The project is being carried out with a general contractor. During planning, it turned out that the proposed location for the air source heat pump (behind the garage, at the neighbor’s property line) is not allowed because:
  • The location is behind the building boundary line
  • The required setback of 3m (10 feet) from the neighboring property is not met
After consulting with the city’s planning department, the only possible location seems to be in the middle of our terrace. Since this is very unattractive, I am looking for alternative solutions.

Our general contractor has suggested the following options:
  • Ground source heat pump, with additional costs of at least 15,000 EUR
  • Exhaust air heat pump, probably no additional costs
I now have the following questions:
  • Where can I find reliable information about alternatives to outdoor installation of an air source heat pump? Which organizations or professionals could provide expert advice (possibly for a fee)?
  • What is the difference between an air source heat pump and an exhaust air heat pump?
  • Is an exhaust air heat pump even suitable for a KFW55 house?
Thank you very much and best regards,
ConnyJash
Mycraft20 Jan 2022 11:00
I definitely would not want the device on or even in front of the terrace. The house wall, roof, anywhere else.
ConnyJash schrieb:

According to the architect, this is not possible.
Hmm, it is still done this way daily all around the world...
Tolentino20 Jan 2022 11:07
Deliverer schrieb:

Is there a reason why all the exhaust directions are to the left or right? Why not away from the house?

He doesn't want it blowing onto his terrace...
Deliverer schrieb:

And I’ve asked before: why not towards the street?

The building envelope there is already fully utilized, so if the zoning plan even allows it, he would have to push everything back by almost a meter (thickness of the heat pump plus 30cm (12 inches) clearance).

@ConnyJash Which heat pump was originally planned as standard?
I can hardly imagine that wall mounting should be excluded.
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ConnyJash
20 Jan 2022 11:13
@Deliverer: If the exhaust direction were to be aimed, for example, towards the garden, the unit would need to be rotated. However, the unit is 1.2m (4 feet) wide and would then be positioned in front of the window. Of course, the door could be moved in this case, but then the doors and windows would be asymmetrical. Why is option 1 not a good solution?
It is not possible to install it facing the street because this is explicitly prohibited in the development plan. All attempts to discuss this with the authorities have been unsuccessful.

[B]@Mycraft: I am not familiar with wall mounting. However, since clearance distances probably need to be observed here as well, the only option would be mounting it on the rear wall. But this would mean placing the unit directly in front of the children’s bedrooms, which is likely not ideal.


@Tolentino: The standard installation calls for a Nibe F2120-12.
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Deliverer
20 Jan 2022 11:22
ConnyJash schrieb:

Why is Option 1 not a good solution?
Because KfW55 standard houses usually cannot be heated economically with this type of system. This kind of heating is generally more efficient for buildings between KfW40 and Passive House standards. However, this is a general statement. I’m not exactly sure what this specific model can do (for example, with the optional fresh air supply).
Tolentino20 Jan 2022 11:24
Ok, according to the installation manual, wall mounting is not really intended. This doesn’t mean it’s impossible, but the manufacturer at least does not list it as an option.
Pretty annoying. I think I would then go for geothermal energy instead.
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ConnyJash
20 Jan 2022 11:29
Which option for installing the external fan would be the best? I am fully aware that none of the three are perfect.