Underfloor heating distance, missing spot, and bathtub

Hi,
I wasn’t exactly sure in which subforum to write...

Our site manager asked me whether we want to place the bathtub on the screed or on the concrete. We hadn’t really thought about it so far, but we decided on the concrete floor.
In any case, I was just on site and cut away the styrofoam since the screed work starts on Monday.

I noticed a few things:

1) What is the maximum spacing allowed for the underfloor heating pipes? To me, some distances of 30 cm seem quite large.
2) Is it common to simply leave some spots out? (Like in front of the bathtub, see picture)
3) Where I cut away the styrofoam around the bathtub, there are still some pipes—don’t they cause any issues? And why is such unstable styrofoam placed between the floor and the screed at all?

Thanks in advance
Marvin

What should be the maximum spacing of the underfloor heating pipes? To me, 30cm seems quite a lot in some cases.

This should be calculated beforehand based on a room-specific heating load calculation and not estimated. In the bathroom, usually a very close spacing is used, 10cm or less if you plan with a low supply temperature. However, it depends on the conditions, so the statement should be seen only as an example. Especially if you have a heat pump, it is very important to plan the bathroom well; otherwise, you will have to operate the entire system for all rooms with lower efficiency/higher supply temperature just because of the bathroom.

Ah ok, thanks! Yes, we have a heat pump. So I assume that everything has been calculated correctly? I just sent another email to the installer, let's see what he says.

The spacing seems too large to me. Have a room-wise heating load calculation and installation plan handed over to you. The flow temperature should be planned at a maximum of 30 degrees.

It will get warm enough, but the annual performance factor/electricity consumption suffers if a room is significantly undersized. Usually, it is the bathroom because there is little space available there anyway due to the tub/shower.

In the 15m2 bathroom, we have two 80m circuits with 7.5cm spacing. A circuit should not be longer than 100m in case you have any changes.

All right, I’ll follow up on that! I’ve just quickly uploaded a video, but now I’m not sure if I’m allowed to post it... If not, I’ll remove it again.

[MEDIA=YouTube]XpfchMEQim4[/MEDIA]

Overall, it is laid very neatly. The door transitions are also protected, and it was laid into the door recesses as well.

Not so nice, however, is that some spots, especially corners, were left out. But that is forgivable.

The gaps also look OK. Less than 10cm doesn't make sense, I would recommend 15cm for the bathroom and 20cm for the rest.

So I would say you can be satisfied with the installation.