House entry base plate for heat pump outdoor unit

Hello everyone,

since our construction is starting soon (earthworks), I am now wondering how the necessary pipes for the heat pump (connection from the indoor unit to the outside) should best be routed. I have heard that something is simply used, like a wastewater pipe. I find that a bit strange in a new build from 2022.

What have you used here? There are house entry systems that can be purchased. Allegedly (according to the heating engineer), that doesn’t work so well with the refrigerant lines (copper). However, I wonder where the difference to the 125mm wastewater pipe should lie..

Thanks in advance.

Best regards

Sewer pipe is the cheap option. The correct option would be a multi-duct for the slab.

Basically, both are just empty conduits. As long as they are properly sealed from the inside (press ring), there is absolutely nothing against using a KG pipe. In any case, do not make the mistake of forcing your construction company to use a new system, as it will be installed incorrectly 90% of the time.

The internal sealing for the pipe does not replace the external sealing to the building structure - i.e., without additional measures, a KG pipe is not watertight under pressure and certainly not radon-tight. There are also solutions for this ([Dichtkragen]), but they also need to be installed correctly.

The problem is always that the standard multi-duct sleeves are simply too small for certain types of pipes - with DN125 it is much easier to introduce rigid pipes, even bundled.

However, there are also larger single and multi-duct sleeves - e.g., Kraso BKP 110 or Doyma Quadra E-BP-Max, which also come with appropriate sealing inserts for the usual refrigerant pipes. Disadvantage: they are relatively expensive, and as Gecko1925 rightly says, they are often partially installed incorrectly.

Okay, thanks for the info. Another possibility would be the Hauff ADS150 floor box for floor slabs, which then have a slightly larger inner diameter. There would also be ring space seals with corresponding diameters for cables and lines. Such a 100 single conduit only has 78mm inner diameter. Maybe it would be easier for them with a 150? I just didn't want to get a leak into the technical room (which is directly connected to the house). Don't want water, radon, or "pests" coming in through a poorly sealed KG pipe.

Since our construction is starting soon (earthworks), I am now wondering how the necessary lines for the heat pump (connection from the indoor unit to the outside) should best be laid. I have heard something about simply using a sewer pipe. I find that a bit strange in a new building from 2022.

Question: Does it absolutely have to go through the floor slab? Where is the heat pump located? If it is "only" in front of the house connection room (on the ground floor), you simply go through the wall. The route should always be as short as possible.