Grundfos silence

Pumps can be used to balance a heating system quickly and accurately.

What to do about noise in heating systems

Noise in a heating system is a well-known issue for installers. The noise can come from the pump, the pipes or the radiator thermostats – and it can be caused by either the mechanical parts of the system, air in the system, or the water or fluid in the system. Since hydronic systems easily transport the noise, it can be difficult for the installer to know exactly where the noise is coming from.

In general, there are two main causes of noise in heating systems – wrong or incorrect commissioning and wrong dimensioning.

Noise due to incorrect commissioning

In many cases, the noise problems are caused by the system operating at too high a speed, resulting in a higher flow than is needed. When this happens, it forces the valves to compensate by trying to close, causing friction in the system which can create noise.

Another cause is lack of balancing or wrong commissioning of the entire heating system, creating uneven flow and pressure across the system. This causes high stress in some parts of the system and results in noise from radiator valves.

Noise due to wrong dimensioning

A common reason for noise in heating systems is incorrect dimensioning of the system parts. If the pipes are not sufficiently dimensioned according to the needed flow, it can create friction noise in the pipes and valves.

Other common causes of noise

Air in the system, resonance noises, cavitation noise and deposit build-up are other causes that can create noise in the system.

How to avoid noise in a system

Correct selection, sizing and commissioning of the pump, including correct selection of pump settings with automatic adaptation (AUTOADAPT), ensures the differential pressure will not exceed the normally needed level. A balanced system will remove any uneven flow and pressure across the heating system, minimising the risk of noise when heat demand changes during the year.

Grundfos lab tested

Grundfos circulators are tested in Grundfos’ own sound laboratory. In the sound lab the circulators undergo very comprehensive noise tests with the focus on the noise emitted through air, water and the piping structure. Grundfos strives to make its pumps as quiet as possible but, no matter how well-tested these components are, it is impossible to fully replicate the diversity of real installations. This means that installers should play a crucial role in designing, dimensioning and commissioning heating systems correctly. When the system is noiseless, it often means it is running optimally and the homeowner is ensured full comfort and optimal energy consumption throughout the entire heating system. This also means less call-backs for the installer.

For further information visit www.grundfos.ie or contact salesireland@sales.grundfos.com