ᐅ Underfloor Heating: Is the Pipe Length Too Long?

Hello,

The plumber installed the underfloor heating today. For all heating circuits on the ground floor, upper floor, and basement, the pipe lengths are under 100m (330 feet). However, one heating circuit is about 140m (460 feet) long with a pipe diameter of 16mm (0.63 inches). The plumber says this is not a problem and that the heat pump can handle it. Can I trust this, or could I face issues like pressure drop, insufficient heat output, or something else?

What do you think? Maybe there’s a plumber among you?

Many thanks, Andreas

Is there anyone who can answer my question?

The air-source heat pump is the Junkers SAS 8-2 ASE split unit with a 25-60 pump. Unfortunately, I have not received a calculation.

What disadvantages arise if the pipe length of the underfloor heating is exceeded?

I assume that either the pump is operating at its performance limit or the corresponding heating circuit cannot be supplied with enough heat.

<<-- Still a novice

I once spent quite some time reading about this online and also heard of lengths up to 180 meters (590 feet). Eventually, I accepted that it comes down to trust. Fortunately, I have never heard of underperforming underfloor heating installations.