Air-to-water heat pump sizing in new construction

In the upstairs bathroom, the small area, in my opinion, was quite well covered. Unfortunately, even after long discussions, the general contractor did not want to completely change the shower location nor the area under the bathtub. Upstairs, the 5cm spacing was still quite well achieved. I would have estimated about 7cm for the downstairs WC (should be 5cm). Except for the hallways and bathrooms, everything is now completely with 10cm spacing and looks really good in my opinion.

How did you convince your general contractor about the pipe spacing? I am always told by general contractors that the spacing is calculated and designed individually for each room. I am always afraid that the general contractor just wants to save on material costs and ends up installing large pipe spacings (including high flow temperatures)... simply because that's how they've always done it!

Did anything special have to be considered for cooling with the air-water heat pump in your case? For example, when laying the pipes or the installed technology?

Does anyone know if it is possible to simply implement a pipe spacing of 5cm in the bathroom/guest WC + 10cm in the other rooms? Or should you rather use and implement individual room calculations? Can values be specified in the calculation?

How did you convince your general contractor about the installation spacing? With the general contractors, I am always told that the installation spacing is calculated and designed individually for each room.

I had the installation spacing calculated myself based on my target specifications. The result looks like this, for example: Then you had to be persistent.

I had the installation spacing calculated myself using my target specifications. The result looks like this, for example:
Then you had to be persistent.

Did you provide values for the calculation? Like flow/return/RT??? Or how did the values come about?

Desired room temperature and U-values of the house+ZIP code for NAT. Then specification to the calculator: I want to go as low as possible with the flow temperature and the expected heat pump for the maximum volume flow.

It turned out that according to the standard we built a disadvantageous house, so that we can only operate with a flow temperature of 34.5 and a 5K spread.

Have you specified values for the calculation? Like supply/return/room temperature??? Or how did the values come about?

That's exactly how you do it. Because there are many ways to Rome. First, the room-specific heat load must be known or calculated. And then you can achieve the same result (= warm apartment) with 30/26/22 or 40/34/22 (just example numbers). The first with laying distances between 5 and 10 cm, the second with laying distances of 10-15 cm. So either proper planning and a bit more effort (cost) or the usual 08/15. With a high supply temperature, you can heat any dump.

That's exactly how you do it. Because there are many ways to Rome. First, the room-specific heating load must be known or calculated. And then you can achieve the same result (= warm apartment) with 30/26/22 or 40/34/22 (just example numbers). The former with pipe spacing between 5 and 10 cm, the latter with pipe spacing 10-15 cm. So either proper planning and a bit more effort (cost) or standard procedure. With high flow temperature, you can heat any place.

Wouldn't it then be easier to contractually specify: "all rooms 10cm & bathroom 5cm"???