Air source heat pump and controlled residential ventilation in terraced mid-terrace house

Good morning dear community,

We are currently facing a discussion with our builder and the heating / sanitary company.

At the moment, the shell of a mid-terrace house is standing. The house has 2 full floors and a set-back floor.

In both full floors, an interior technical room without an exterior wall is planned. Vaillant Arotherm Plus is to be used as heat generation and distribution.

The air heat pump is to be installed on the flat roof. Water tank etc. is to be placed in the ground floor technical room. House electricity should go to the first floor.

Now, however, the ventilation system is supposed to be installed in the set-back floor in a corridor, because according to the heating company, the ventilation system must be located on an exterior wall.

Can someone confirm or refute this statement?

For us, this would mean that the system would hang openly in the room next to the bedroom! This is simply not understandable to us.

Especially since the technical room on the first floor is still almost empty and the exterior wall is only separated by a small bathroom (about 3 meters to the exterior wall from the bathroom and 2.95m ceiling height).

I hope this is visible in the pictures.

I cannot contribute anything to the technical problem, but I recommend moving the doors to the children's rooms on the first floor so that cabinets can simply stand along the partition wall between the rooms:

I do not know your exact ventilation system, but [Grundstück.] the statement is incorrect. Supply and exhaust air can also be ventilated through adequately sized ducts. Now, it may be that your ventilation system is not designed for this and requires a direct connection to the exterior wall.

I do not know your exact ventilation system now, but "Grundstück." is the wrong statement. Supply and exhaust air can also be ventilated through sufficiently sized ducts. It may be that your ventilation system is not designed for this and requires a direct connection to the exterior wall.

I will try to find out which system is to be installed.

You can also lead the outside and exhaust air through ducts via adjacent rooms - we have done the same in the basement. However, these ducts are quite large, meaning that including their boxing, you lose about 25cm of room height at the location where the duct would be. On the ground floor, this might be possible since you only have to go through the guest WC. It would then need to be checked whether the bike box is in the way (i.e., too high), and whether the [planuntere Außenwand] is suitable (south-facing walls should be avoided). If the ventilation stays upstairs, you can probably enclose it at the indicated spot by having a small chamber built with drywall.