Cold-Water-Circulation with KHS CoolFlow

Four succes factors that ensure flawless drinking water hygiene

4 succes factors that ensure flawless drinking water hygiene

Current obstacle: temperature - the planning hurdle

Inner heat loads

Internal heat loads

High heat loads in installation areas

Heat sources such as hot water pipes in plumbing and heating systems and components in electrical and ventilation systems lead to a rise in temperature of the cold water pipeline to more than 25°C in a stagnation phase of two hours, even if the insulation complies with standard DIN 1988-200.

External heat loads

External heat loads

High ambient air temperatures

High external air temperatures can cause ambient air temperatures of more than 25°C in buildings without air conditioning. In the event of stagnation, cold water temperatures below 25°C can no longer be achieved as a result.

Water inlet temperatures

Where drinking water is sourced near ground level in the summer months, the temperature of water fed into drinking water installations is higher (>20°C), reducing the maximum tolerable stagnation time even more.

Drinking water hygiene is an obligation of the operator

Obligation of the operator

When stagnation occurs, the drinking water takes on the temperature of the environment. This can lead to a change in the drinking water quality that is harmful to health. A temperature rise to over 25°C is particularly alarming, as microorganisms such as Legionella multiply in lukewarm temperature ranges. Operators of public buildings have a particular obligation to ensure hygienically perfect drinking water throughout the entire drinking water installation at all times.

To avoid stagnation alone, the whole water content of the installation must be replaced within 7 days. If this cannot be guaranteed by normal use, stagnation flushing must be carried out. These measures are not sufficient, however, if the temperature of the cold water rises to over 25°C due to internal and external heat loads (see above). In this case, additional temperaturecontrolled flushing is necessary; this is not justifiable, however, in terms of economy and sustainability.

The solution: Cold-water-circulation with KHS CoolFlow

With KHS CoolFlow, cold water temperatures below 20 ° C can now be permanently achieved up to the point of use. The drinking water is distributed via KHS Venturi flow dividers to the tapping point. The KHS CoolFlow chilled water cooler cools and circulates the drinking water. The KHS CoolFlow cold water regulating valve regulates, rinses and shuts off circulation circuits if necessary.

Cold-water-circulation with KHS CoolFlow

Permanent cold drinking water up to every tap – only with KHS CoolFlow!

Sustainable and economical justifiable protection against high cold water temperatures is only possible by means of cold water circulation with active temperature control. In order to allow cold water cooling in conventional installation concepts, an additional pipework system has to be installed. With flow splitter installations, however, that is not necessary, as the piping system already installed to cover the water demand is suitable for cold water circulation and can also be used for this purpose. Existing flow splitter installation can therefore generally be retrofitted with KHS CoolFlow at little expense. By contract with conventional installations, drinking water installations with KHS enable temperature control in all parts of the pipework system right up to the connection of the tapping fittings. Temperatures of < 20°C can therefore be maintained even in buildings with high heat loads where thermal separation with horizontal distribution concepts is possible only to a limited extent.

The benefits

In all areas

  • Permanent temperature control < 20°C at every tapping point
    outlet, even with high heat loads

Use of innovative flow splitter technology:

  • Minimised pipe inside surface area
  • Low number of flushing devices
  • Low maintenance costs
  • Use of the pipework for the water demand


  • With high heat loads, KHS CoolFlow achieves
    payback period of less than 2 years compared with
    temperature controlled using flushing


KHS CoolFlow cold water-regulating valve

Automatic circulation regulating valve with integrated flushing function

3 functions - 1 valve

  • Regulating function: Thermal regulating function with a working range
    from 15°C to 20°C ensures automatic hydraulic balancing
    of the cold water circulation system
  • Flushing function: turbulent flow in all areas of the drinking water installation
  • Shut-off function: electrical shut-off function for absolute control of the system
    from one central points

100% planning certainty

One control range for all applications simplifies dimensioning and guarantees reliability at all stages of planning and operation

Easy to retrofit

Existing KHS systems can be retrofitted at little expense.

available from 1st quarter 2020

KHS CoolFlow cold water cooler

Continuous-flow drinking water cooler with integrated
circulation pump

Huge performance with minimum space requirement

With a space requirement of less than 0.5 m, properties with a pipeline length of up to 2000 m can be cooled to less than 20°C.

The all-rounder

Thanks to an innovative storage solution, it can be used in all existing and new chilled water units and cold water chillers.

The complete package

The pre-assembled compact unit with integrated circulation pump already contains all the necessary components for the drinking water side, it is insulated condensate resistant and preconfigured.

KHS CoolFlow chiller

KHS CoolFlow chiller

Air-cooled chilled water unit for connection to the KHS CoolFlow cold water cooler

Demand-driven cold water production

  • Maximum efficiency thanks to preconfigured controller connected to the
    KHS CoolFlow cold water cooler
  • Infinitely variable cooling control with extremely low noise level of 68.5 dB(A)
  • Low space requirement of less than 1.0 m² with a cooling capacity of up to 10.0 kW