Quietly Powerful: Hoymiles HoyUltra 2 C&I ESS Achieves Breakthrough ≤60 dB(A) in Certified Noise Testing

HANGZHOU, February 11 – As energy storage systems (ESS) are increasingly deployed in commercial centers and residential neighborhoods, noise levels have become a critical factor for project approval. Hoymiles’ HoyUltra 2, the liquid-cooling C&I battery system, has achieved ≤60 dB noise level certification in a recent noise evaluation test conducted according to the international ISO 3744:2010 standard by the Zhejiang Electric Safety and Quality Inspection Center. While the industry average is 65–75 dB, the breakthrough ≤60 dB certification of HoyUltra 2 sets it as one of the quietest in the industry.

The gold standard of silence

Unlike tests conducted in noisy industrial environments, the HoyUltra 2 was tested in a professional semi-anechoic chamber with a background noise level of just 24 dB—quieter than a bedroom at night.

The evaluation covered the system's entire operational cycle, including full-power charging and discharging. The results confirmed that even under maximum load, the noise remains consistently low and stable, free from mechanical hums.

Seamless urban integration

At the overall A-weighted sound pressure level of 47.4 dB(A), the operating volume of the HoyUltra 2 is comparable to a quiet library. This is a significant leap from traditional ESS units, which typically operate between 65–75 dB.

This breakthrough allows the HoyUltra 2 to blend seamlessly into noise-sensitive environments, such as:

• Commercial business districts

• Industrial parks

• Residential communities

Innovative liquid-cooling engineering behind the low decibels

• The silence of the HoyUltra 2 is a result of "System-Level Quiet Engineering", which integrates acoustics into product design from the very beginning:

• Multi-dimensional noise suppression: Hoymiles has optimized the refrigeration system and air duct architecture to enhance heat exchange efficiency while eliminating internal turbulence.

• Balance of efficiency and quietness: The coordinated control for fans and compressors prevents unnecessary and excessive high-speed operation.

• Fully liquid-cooling architecture: Compared to traditional systems, the fully liquid-cooling architecture achieves significantly fewer fans and lower RPMs, controlling noise at the source.

• Acoustic stability and control: The seamless alignment between the product’s physical form and its acoustic profile proves that noise control was a core design requirement from the initial layout phase.

By removing the "noise barrier," Hoymiles is opening up new possibilities for ESS deployment where space is tight and neighbors are close.

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