Air cleaner – fan noise
1
Added sound absorbers, optimized for frequency range 100-500 KHz.
2
Custom-made noise trap with Acustimet.
3
Holes optemized for better noise control.
Noise problem solution
Costumer: Camfil
Noise problem: Fan noise
Material used: Acustimet®, Acusticell
Result before – after: 52 dB – 28 dB
Camfil, a global leader in air filtration systems, needed to address fan noise issues in their City M air cleaner—a popular choice for indoor environments such as offices, hospitals, and schools.
The internal fan produced a noticeable noise level, which became especially disruptive in quieter settings. This was a concern for end users prioritizing both clean air and acoustic comfort.
To solve this, we implemented a three-step acoustic upgrade:
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A customized, high-efficiency sound absorber was installed inside the casing.
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A sound trap made from Acustimet was integrated to reduce fan noise along the airflow path.
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The hole pattern on the front panel was optimized to minimize resonance and noise leakage.
The result:
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Before: Noticeable fan noise, particularly during high-speed operation.
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After: Significantly quieter operation, with a smoother and more pleasant sound profile—achieved without compromising airflow or filtration performance.
Soundproofing the Camfil City M air cleaner – Case Study
The Camfil City M is a high-performance air purifier designed for indoor environments such as offices, hospitals, and schools. While its filtration capabilities are exceptional, the built-in fan can generate noticeable noise, especially in quiet settings. To address this, we implemented a multi-step soundproofing strategy focused on maintaining airflow and performance while reducing operational noise.
1. Custom acoustic absorber integration
We developed a tailored sound-absorbing insert using high-efficiency acoustic foam. This insert was installed inside the unit’s casing, specifically in areas near the fan where sound reflections and vibrations are most intense. The material is optimized for mid- to high-frequency noise and meets strict fire safety standards.
2. Acustimet sound trap
To further attenuate noise without hindering airflow, we designed and installed a sound trap made from Acustimet. This perforated metal element, filled with sound-absorbing material, is strategically placed within the air channel to break up and dampen noise from the fan blades and motor housing.
3. Optimized hole pattern in the casing
We redesigned the perforation pattern on the air cleaner’s front panel. By optimizing hole sizes and spacing, we reduced resonance and sound leakage while preserving the airflow rate. This seemingly small design change has a notable impact on perceived noise levels, especially in quiet environments.
Result
Thanks to this three-part intervention, the Camfil City M now operates at a significantly reduced noise level—ideal for sound-sensitive environments such as schools, clinics, and offices. The improvements were made with no negative effect on filtration efficiency or maintenance accessibility.
52dB ⇒ 28 dB
Product resources
Camfil City M datasheet (swedish)
Camfil City M product video
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