Advantageous hot water pipe installation through ring main

When installing the hot water pipe network, economic and hygienic optimization is more in demand now than ever. A sensible alternative to row or T-piece installations is the ring line installation. We explain how it works and what it brings.

This is how a hot water ring main works

Various methods can be used to protect the warm drinking water in the house from contamination and to achieve hydraulic balance. The following are typically used:

  • Row installation
  • Tee installation

With these pipe laying systems, the individual tapping points are supplied with water one after the other.

Another option that is becoming increasingly popular is the ring installation. With this technology, the tapping points within a floor are not supplied with water one after the other, but parallel and in a ring shape from two sides. This works by dividing the drinking water pipe into two lines at the first tap. Above all, this has advantages for water hygiene and significantly reduces pressure losses. In addition, the assembly effort is somewhat less overall compared to conventional techniques.

Hygiene through regular flushing

Since the respective ring line is completely flushed through when drawing from any tap on each floor, there is a much brighter and more efficient water exchange compared to conventional systems. And that is an important factor in preventing pipe contamination. At the same time, the flow volume in the ring main is kept low because the pipe diameter can be kept significantly smaller by connecting the divided flow lines in parallel.

Furthermore, with the ring installation, the hot water temperature in the line is not kept permanently high, since the water cools down relatively quickly when the tap is not being used. This results in a lower risk that hot or cold water will remain in the critical temperature range between 25 and 55 ° C for a longer period of time.

Insignificant comfort disadvantages

In terms of hydraulic efficiency, a ring installation does not have any noticeable disadvantages. It is true that it provides hot water more slowly than T-piece installations. At a request temperature of 42 ° C, however, at 15 seconds, it only takes 4 seconds longer than the 11-second alternative. According to VDI guideline 6003, an ejection time of 7 to 26 seconds is regarded as conforming to the standard or. acceptable.

Interpretation a little more complicated

Because the tapping points in the ring main are fed from two sides, the design is somewhat more complex. DIN 1988-300 recommends the Hardy-Cross method for individual calculations, in which the volume flows are determined.