ᐅ Connection of Monoblock with heat pipe above or below the concrete slab?

Hi.

My heating company hasn’t dealt with the connections yet. For the foundation slab, I need to decide whether there should be a connection from the utility room to the outdoor unit of the heat pump (mono) running through the foundation slab. So, should the pipe (PUR-insulated local heating pipe 130 from the manufacturer) be installed under the foundation slab, or should it be laid on top of the slab within the insulation layer after the shell construction? What experiences do you have?

Option 1: Under the foundation slab... inside a 160mm (6.3 inches) empty conduit? Or directly without an empty conduit (connection pipe could be laid directly)? The house entry would then be professionally sealed using the connection kit. For the empty conduit, probably a KG 160 pipe would be used.

Option 2: Use the same insulated connection pipe from the manufacturer or a cheaper connection from the heating company? So, uninsulated pipes running to the house wall inside the insulation layer between the foundation slab and the screed?

I hope these are not too silly questions. Thanks.

Best regards,
Steffen

My general contractor wanted to run the pipes through the slab by default. The heating installer (not a subcontractor of the general contractor) preferred to route them through the wall, specifically above the finished floor level. That way, he could insulate it properly himself. The advantage is that if there is ever an issue, it’s easier to access. Running the pipes through the wall (whether under the screed or above the finished floor) usually means shorter pipe runs—you don’t have to go down 2 meters (6.5 feet) into the floor and then back up. The pipes are already quite stiff, so how do you properly insulate around them? Sure, you could foam the entire pipe, but that would likely be more expensive than making a core drill hole through the wall.

Either use insulated piping beneath the concrete slab (district heating pipe) or run it directly through the wall if the boiler room is located immediately behind. However, please do not place any heating pipes directly on the concrete slab.

KarstenausNRW schrieb:

Either with insulated piping under the slab (district heating pipe) or directly through the wall if the boiler room is located immediately behind. But please do not lay any heating pipes directly on the slab.

Thanks. That’s exactly what I thought. The heating engineer initially suggested running the pipe for 8 meters through the house on the slab within the insulation layer. The 10m (33 feet) district heating pipe will now be installed under the slab. The pipe has been ordered and is hopefully arriving by the end of the week.

Would you have this pre-insulated district heating pipe, 130mm (5 inches) diameter, installed inside a separate conduit (160mm or 200mm) as well?

Thanks, Steffen

We had KG pipes installed beforehand, including through the foundation slab. Afterwards, the line was pulled through and sealed. According to the company, it would be possible to replace it later in case of an emergency.

cryptoki schrieb:

Would you install this pre-insulated district heating pipe, 130 millimeters (5 inches) in diameter, inside a separate conduit (160 or 200 millimeters (6 or 8 inches))?

Please do not use a conduit. There is a) no reason for it (the pipes are designed for this purpose) and b) it becomes practically impossible to pull the extremely rigid cable through bends if needed.