STULZ, Merford conduct unique acoustic test for data centres

Author: Joe Peck

STULZ, a manufacturer of mission-critical air conditioning technology, and Merford, a Dutch specialist in noise control systems and acoustic doors, have completed an acoustic test confirming that a newly developed chiller system can meet strict data centre noise regulations under operational conditions.

The test was carried out on a chiller for a project in Valeggio sul Mincio, Italy. It used a validated measurement methodology designed to reflect real-world performance, as operators increasingly consider noise alongside cooling capacity and energy efficiency.

As data centre power densities increase, larger cooling systems can create greater environmental impact, particularly in urban locations. The project required compliance with a maximum night-time noise level of 80.2dB(A), prompting acoustic considerations to be integrated early in the design process.

Davide Mazzi, Head of the Application Team at STULZ, explains, “The challenge was not only to guarantee efficient cooling, but to comply with extremely strict noise limits.

“The installation is located on a rooftop in a densely built urban environment. Our task was to deliver the required performance without disturbing the surroundings and without compromising the operational reliability of the data centre.”

Acoustic testing under real operating conditions

The companies developed a noise attenuation system tailored to the chiller configuration. Acoustic measurements were conducted in line with EN ISO 9614-2:1997, which determines sound power levels using sound intensity measurements.

Before testing, the team carried out an environmental analysis using SoundPLAN software to model sound propagation. The test setup ensured that background noise levels were at least 10dB below the chiller’s output, with surrounding equipment positioned to avoid interference.

Two attenuation configurations were assessed: Both used steel frame structures with integrated acoustic components to reduce airborne and structure-borne noise, while the second configuration also included additional optimisation measures, resulting in greater overall noise reduction (although it increased system weight and complexity).

Engineers measured sound power levels with and without the attenuation system to quantify performance and confirm compliance with the required limits.

Davide continues, “We were delighted to find that the chiller equipped with the developed attenuation system successfully met the stringent noise requirements.

“This project demonstrates that data centre cooling and acoustic compliance can be achieved simultaneously when engineering, acoustic design, and validation are approached as an integrated process.

“As data centres continue to expand into urban environments, such integrated approaches are likely to become essential for balancing performance, sustainability, and community impact.”