Interpretation of the LWPump the builder's responsibility?

Hello, we want to build with a contractor. The fine print regarding the heating system states: "...the named heat pump is sufficiently designed for heating. The exact requirement results from the heat demand calculation. It may become necessary to use a more powerful heat pump. The additional costs will be borne by the client." Is this legal?! I pay a flat rate for a heat pump and don't even know if it is sufficiently designed. Isn't it the contractor's responsibility to ensure this?!:mad: Also the point about wall brackets and fastening (wall penetrations and electrical supply by the client) Is this normal?

Hello,

Hello, we want to build with a construction contractor. The fine print regarding the heating system states:
"...the named heat pump is sufficiently designed for heating.The exact demand calculation results from the heat demand calculation.

Apparently, they don't really know what is meant :o

..It may become necessary to have a more powerful heat pump. The additional costs will be borne by the client."

Something is being tampered with there. It certainly won't be energy efficient!

..Is that lawful?! I pay a flat rate for a heat pump and don't even know if it is sufficiently designed. Isn't it the contractor's job to ensure this?!:mad:

If a higher output is actually required?? The more powerful heat generator must always be paid for by the client. However, the question is whether this has been calculated with sufficient accuracy. They simply estimate and assume (back of the envelope calculation + safety margin).
Good luck with this building technology!

I can only recommend having the heating load, heating surfaces, and pipe network calculated externally, as well as having the heat generator dimensioned externally, and then providing the parameters to the general contractor!

Best regards,

With the above procedure, money is made from additional claims/extensions. In the end, the project may be more expensive than a comparable one!

They apparently don’t really know what is meant :o Something is then fiddled in. This will almost certainly not be energy efficient!

If a higher output should actually be required???, the more powerful heat generator must always be paid for by the builder. However, the question is whether this has been calculated precisely enough. They simply estimate and speculate (rule of thumb + safety margin). Have fun with this building technology!

I can only recommend having the heating load, heating surfaces, and pipe network calculated externally, as well as the heat generator dimensioned externally, and then giving the parameters from that to the general contractor!

Best regards

With the above procedure, money is made through additional claims/extensions. In the end, the project may be more expensive than a comparable one!

Thank you for the detailed answer. What is meant by pipe network and heat generator (heat unit?) "Something is then fiddled in" that is absolutely right, because we initially decided on a 160 sqm house with a mezzanine and have now switched to two floors of 150 sqm. In both cases the same heat pump.

Hello,

.... What is meant by Rohrnetz and WE (Wärmeeinheit)?

The Rohrnetz is the entire system that transports the heating water to the heating surfaces. While the mass flows result from the heating load or heating surface calculation, the pressure losses are determined in the Rohrnetz calculation. Only then can, for example, pumps and other components be selected.
WE => Wärmeerzeuger

..."They fiddle something in there"
that is absolutely right, because we initially decided on a 160 sqm house with a split level and have now switched to 2 floors with 150 sqm. Both with the same heat pump.

This is already an indication of a fairly superficial approach.
Mostly, the general contractors have a "house brand." This is then "fiddled in" regardless of whether it is really optimal.
Getting the building warm later on is not necessarily the biggest difficulty. The problem is then the actual energy efficiency.
Modern technology is expensive and offers many possibilities, but the potentials can only be tapped with precise planning. Calculated over a usage period of about 25 years, lacking energy efficiency will noticeably impact the wallet.

Best regards