Is a multi-branch gas supply connection usable for an air conditioner?

DN25 is already tight, but both copper pipes including insulation should fit through.

With us, the refrigerant pipes including insulation are each 3cm in diameter, you can't get them together through such a straw. However, it might be possible to lead the power cables of the indoor units through the multi-utility entry (MSH) to the outdoor unit, as well as the power cable for the outdoor unit itself.

I have the feeling that the providers rely on relatively strict regulations.

That's right. If own cables are to be routed through the MSH, it must be clarified with the provider. There are municipal utilities that do not tolerate "foreign cables" in the MSH.

But what's with the fuss about the thermal envelope? An exhaust hood, a chimney, or a controlled residential ventilation also bridge the thermal envelope in their own way, and nobody has any concerns about that.

The discussion is off. Of course, you penetrate the sheath to get cables outside. The multi-utility house entry will hardly be sufficient for the majority, also not for the [Klima].

1.
There are municipal utilities that do not tolerate "external lines" in the HVAC system.

2.
But what’s with all the fuss about the thermal envelope? An exhaust hood, a chimney, or a controlled residential ventilation system also bypass the thermal envelope in their own ways, and no one worries about that.

Regarding 1.
It would be very practical if you only needed one trench that leads from the basement to the outside. However, you don’t need to lay it that deep for air conditioning units anyway, because there are also above-ground lines for that, right?

2. Yes, the fuss is annoying. But I was already categorically refused even one exhaust vent. In the meantime, I am somewhat more relaxed about it, since the energy consultant (same company) explained to me past the project manager that it doesn’t matter. The opening is already planned THERE. But it does make a difference whether it concerns the Renewable Energy Act subsidy or the warranty, respectively the guarantee of the house manufacturer for the house itself. The basement is being built as a self-build.

It would be interesting to hear from people with [Holzständerbauweise], which we belong to, how they get the condensation water out of the indoor units.

With us, the refrigerant lines including insulation are each 3cm in diameter, you can't get them together through such a straw. However, you might be able to route the power cables of the indoor units through the multi-utility entry (MSH) to the outdoor unit, as well as the power cable for the outdoor unit itself.

That's right. If you want to pull your own cables through the MSH, you have to clarify that with the utility provider. There are municipal utilities that do not tolerate "foreign cables" in the MSH.

As long as you live in an area where there is THE provider who supplies everything from a single source. I've read something like that here in the forum for the first time; here there is a separate provider for each utility. Otherwise, just install according to the municipal utilities ;).

Preparing an additional empty conduit in the floor slab accordingly should actually be the easiest thing!? This is recommended anyway as mentioned by . You can then lead any lines or cables outside...