Smart heating and saving costs with HERZ
Hydraulic balancing made easy

Efficient heating starts with a simple but often overlooked measure: hydronic balancing. Particularly in renovation projects, hydronic balancing has the potential to significantly reduce heating costs, save energy and increase living comfort. But what is the easiest way to implement hydronic balancing in practice – and which HERZ products can help?

The challenges of old buildings

Many existing buildings have outdated heating systems that are neither efficient nor do they distribute heat evenly. This often results in the problem of so-called ‘cold corners’: rooms that do not get properly warm, while others are overheated. The cause? An insufficiently implemented or completely missing hydraulic balance. Without it, the heating water does not distribute optimally in the system. The problem is particularly noticeable in single-pipe heating systems, which are common in older buildings. However, the importance of hydraulic balancing is often underestimated. The potential is enormous: if hydraulic balancing is carried out correctly, energy savings of 20% or more can be achieved, heating costs reduced and living comfort increased.

Renovating two-pipe heating systems: the issues

In two-pipe heating systems, all radiators are supplied with the same flow temperature because they are connected in parallel to the same flow line. The correct distribution of the heating water between the radiators is the biggest challenge. Especially in larger installations, the differential pressure often fluctuates greatly, making it considerably more difficult to achieve optimum regulation.

Renovating single-pipe heating systems: the issues

Single-pipe heating systems often pose a challenge, as the heating water circulates serially through the individual radiators and thus cools down after each radiator. A hydraulic alignment in such a system requires specially coordinated solutions. In addition, such single-pipe systems tend to have pressure imbalances, especially in larger buildings. One major difference between this and two-pipe heating is that, in single-pipe systems, it is often the entire apartment that needs to be regulated rather than the individual radiators. This is because the heating circuit in single-pipe heating systems works differently: One radiator receives about 60-70% of the volume flow, while the remaining 30-40% is routed to the other radiators via a bypass. If a radiator is closed by a thermostatic valve, the bypass cannot transfer the entire volume flow. This means that radiators in rooms further away do not receive sufficient heat – exactly what you want to avoid.

The solution for the modernisation of one- and two-pipe heating systems

Measure 1:
An easy-to-implement renovation measure for hydraulic balancing in single- or two-pipe heating systems is to use a presettable control and regulating valve with an actuator at the ‘root’ of the flat to adjust the volume flow to the heating load. Supplemented by a room temperature controller, the system can be controlled so that the control valve interrupts the heat supply when the desired room temperature is reached. This helps to get a grip on the frequent problem of overheating and to use energy more efficiently.

Measure 2:
In the case of two-pipe heating systems, it is also recommended to renovate the individual radiators. To enable the flow rate to be adjusted individually for each radiator, it is recommended to convert to presettable thermostatic valves with thermostatic heads. This means that hydraulic balancing can be achieved with little effort. This measure is only recommended for two-pipe heating systems.

Measure 3:
However, anyone who wants to make the system of their single- or two-pipe heating even more efficient should also look at the circuits. With a circuit regulating valve per circuit, the flow can be regulated. In combination with the differential pressure controller, which monitors and regulates the pressure drop between the flow and return of the respective circuit, nothing stands in the way of successful hydraulic balancing.

Hydraulic balancing with HERZ: Products and training on the subject

Hydraulic balancing is not an optional extra, but an essential measure for a smoothly functioning heating system and efficient energy consumption. With hydraulic balancing, unnecessary heating costs can be avoided while increasing living comfort. HERZ not only offers suitable products, but also training and practical support for installers, planners and owners on the subject of ‘hydraulic balancing’ in its own training rooms in the 23rd district. With the help of practical case studies and the opportunity to put the theoretical knowledge they have learned directly into practice at the company's own laboratory stand, both small groups and groups of up to 40 people are trained in theory and practice. Appointments can be made at any time at herznews@herz.eu.