NA 041

DIN Standards Committee Heating and Ventilation Technology and their Safety


Hydronic systems in heating, cooling and ventilation installations - Part 4: Temperature-based alternatives to hydronic balancing


This document describes the procedure and methods for implementing temperature-based alternatives to hydraulic balancing with the aim of hydraulically optimizing heating, cooling and ventilation systems. Temperature-based approaches are described and classified with regard to essential characteristics. The hydraulic balancing - i.e. hydraulic influence to avoid local over- and underruns of suitable set flow rates - is performed on the basis of temperature measurements and other variables or information. In addition, methods are dealt with which do not allow individual hydraulic balancing of the supplied transfer devices, but which aim at a substitute optimization by reducing simultaneities of unregulated flow processes. For the purpose of conceptual differentiation, we do not speak of hydraulic balancing methods, but of simultaneity-based optimization methods without individual balancing. Both approaches are summarized in the context of this standard under the generic term of hydraulic optimization. In addition, the so-called adaptive hydraulic balancing (by means of balancing systems that adapt themselves automatically both initially and repeatedly/continuously during operation) is of particular importance in the context of temperature-based balancing methods, since adaptive balancing systems currently available on the market are generally temperature-based. The prerequisite for the application of the standard is a properly dimensioned and installed hydraulic system from generation to transfer (including piping, heat transfer equipment, if necessary storage tanks, valves, pumps, if necessary heat exchangers, etc.). A quantitative assessment of the effectiveness - e.g. evaluation of the energy saving potential compared to the hydraulically unregulated state - as well as a classification of the effectiveness in the context of conventional hydraulic balancing on the basis of calculation values are not part of this part of the standard. For the purpose of conceptual differentiation from the approaches of conventional hydraulic balancing based on the determination of set flow rates, the temperature-based approaches considered in more detail here are referred to as temperature-based methods/systems of hydraulic balancing or temperature-based hydraulic balancing.



Planned document number

DIN 94679-4

Project number


Responsible national committee

NA 041-05-01 AA - Design and energy performance of heating systems and water based cooling systems and DHW in buildings 

draft standard

Hydronic systems in heating, cooling and ventilation installations - Part 4: Temperature-based alternatives to hydronic balancing
Order from Beuth Verlag


Dipl.-Ing. (FH)

Frank Lange

Am DIN-Platz, Burggrafenstr. 6
10787 Berlin

Tel.: +49 30 2601-2317
Fax: +49 30 2601-42317

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