Hydronic balancing and control

The short way to optimal heating.

Lower heating costs and more living comfort thanks to automatic hydraulic adjustment.

Here you will find all relevant information about hydraulic adjustment. Animations, articles, infographics, videos and guides to help you in your daily work.

The hydraulic balancing of heating systems

Over 80% of all existing heating systems have huge potential for optimization. The hydraulic balancing ensures the optimal distribution of the water flows in a heating system so that the right amount of heating water is available at the right time in the right place in the building
This is by no means just a question of the suitable components, it also requires an understanding of the entire heating system. It must be analyzed, calculated, adjusted, and optimized.

Find out more here.
A tip: discover the graphic. Do any of the practical questions sound familiar to you?

Where do the flow (sissling) noises on the radiator come from?

Answer: Actually always caused by excessive flow velocities at the radiator valve due to excessive differential pressures. The cause: Incorrectly set or not set external circulation pumps, condensing boilers with integrated pumps and, especially in larger systems, excessively high differential pressures in the case of partial loads due to the lack of zoning and manual balancing valves.

Smart Home and hydraulic balancing - is there a connection?

Answer: Regardless of which Smart Home system you use for individual heating control: The basis for maximum efficiency and living comfort is always hydraulic balancing. Important: The valve housing and sensor elements (drives) should always be matched to one another. My tip: Systems that adapt themselves need time for the desired mapping of the individual usage profile.

Why is the return temperature too high?

Answer: Quite simply: Because, i.e., no hydraulic balancing was carried out. In condensing systems in particular, the return temperature must be as low as possible so that the highest possible degree of condensation (use of latent heat) is achieved over the entire heating period for the exhaust gas heat exchanger . If the volume flow at the individual radiators is limited, the heating water simply has enough time to release the heat (constantly), which leads to a lower mixed water temperature in the return.

Why do I need a differential pressure controller?

Answer: In order always to provide a constant differential pressure in a volume-variable system (here 2-pipe systems), you need a balancing valve to fulfill this function. And this for every load case from 0-100%. In small systems, this can also be done by the heating circulation pump (with a constant differential pressure setting) provided the minimum setting value is below 150 mbar (reference value).

What do I have to consider with a new heat generator?

Answer: Unfortunately we often experience that the outout of the new heat generator is only matched to the heating load of the building or the residential apartment. At the same time, however, must the heat distribution = hydraulic balancing also be tackled. Hydraulic balancing is state-of-the-art and "the" foundation for heating optimization.

And what role does user behavior play?

Answer: An increasingly important one! Ultimately, the goal of heating optimization should be that the user feels comfortable and at the same time saves energy and money. Every heating system has (physical) limits that you should be aware of. Anyone who understands the system dependencies can point out these limits and be able to point out possible solutions.

Is the heating curve set correctly?

Answer: What do you mean by “correctly set”? It's not just about the relationship between the flow and the outside temperature for a heating circuit. Here, the requirements of the heat generator (e.g. condensing boiler via a heat pump) for maximum system utilization must be taken into account, as well as the system dynamics in the case of partial loads.

When does it make sense to replace the heating circulation pump?

Answer: It certainly makes sense to replace an old “electric power guzzler” with a new high-efficiency pump. But please do not just install but also adjust! And this is only possible after calculation or calibration.
In addition, documentation of setting is mandatory for many subsidy measures. Important: A new pump does NOT replace hydraulic balancing - both belong together!

How big are the pressure losses in the pipelines?

Answer: A good question, especially in existing systems. A pipe system calculation is almost never available. At the same time, however, the question arises of how important and time-consuming, at least for smaller residential units, a (re) calculation is and how great the effects on the dimensioning and setting of the components are.
At this point, it is also important to take the dimensioning parameters of the heat generator into account.

How do I determine the presetting on the thermostatic valve?

Answer: It is best to use a calculation according to the procedures A and B, which are now established on the market and prescribed for subsidy schemes (without or with consideration of a simplified, room-by-room heating load calculation). Important at this point: Please avoid small presetting values due to reduced differential pressures. This means that any hydraulic problems caused by dirt in the heating system can be avoided in the long term.

Hydronic balancing and control 6 Items