Exceptional comfort while saving - in heating and cooling systems

The “Hydraulic Compensation“

The hydraulic compensation, if any, is usually performed during full-load operation and by means of an initial setup of the throttling devices in heating and cooling circuits. The partial-load operation is not taken into consideration which results in imbalances when the control valves are partially closed. Systems that have not been hydraulically compensated are often operated with a significantly excessive pump speed for sufficiently supplying the poorly connected consumers.

This means: The plants are not operated efficiently, the rooms remain cold or are overheated or the temperature swings up and down.

Figure 1: System WITHOUT hydraulic compensation
Figure 2: A system which has been compensated by means of the DIGICONTROL HYDROMIZER

The Solution

The DIGICONTROL HYDROMIZER module calculates the dynamically compensated state ..
.. even if the hydraulic system has been compensated inadequately.



  • Permanent hydraulic compensation during full-load and partial-load operation
  • Constant room temperature, no swinging, consistent heating
  • Energy saving of about 30% (pump)
  • Return temperature corresponds to dimensioning
  • No noises due to flow velocities that are too high
  • Little effort for planning and commissioning
  • Automatic detection of pressure loss coefficients in the pipe network
  • BACnet integration into existing BACnet systems
  • Low installation costs for ems4.HYDRO module: Simply snap it onto the top hat rail, connect it with the automation station via plug and configure it by means of webCADpro. The innovative Hydromizer software is embedded in the ems4.HYDRO module.


Take advantage of our expertise!

For all questions, starting with the planning, implementation, optimization and support of your buildings, you have only one contact person with GFR.



How it works:

The volumetric flow of each individual valve can be calculated in case of a known actuating value by measuring the pump pressure and the total flow rate via just a single sensor. Furthermore, the mutual influence of the volumetric flows can be eliminated by individual valve operations.

The following measuring values are sent to the Hydromizer to ensure its function:

  • The volumetric flow V point of the entire system
  • Differential pressure Δp which is generated by the pump
  • All valve positioning values Yi of the system (originate from the single room control)
  • Layout of piping, only series and parallel connection of radiators here


The hydromizer calculates the KVS values of the valves and the pressure loss coefficients ζ of the piping from the different correlations of the input values. The calculation with the minimisation of pump performance automatically results into fully opening a valve and the other valves working with actuating values below 100%. The pump is controlled in a way that the most poorly connected valve opens up 100%. All valves being better connected are throttled to such an extent that they are only passed through by their specified volumes. They are no longer preferred due to their hydraulic connection.

The system is permanently in the hydraulically compensated state (also in partial-load operation).

Figure 3: Example
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