How do modular cleanrooms reduce noise?
Modular cleanrooms primarily achieve noise reduction through three core pathways: optimized structural design, material selection, and system noise reduction. Ultimately, indoor noise levels are controlled at 45–65 dB(A) (meeting ISO 14644 and GMP cleanroom noise standards). The specific noise reduction solutions are as follows:
Structural Noise Reduction: Blocking Noise Transmission at the Source
1.Modular Panel Sound Insulation Design: Utilizing double-layer color steel sandwich panels (core material: rock wool/polyurethane), panel thickness ≥50mm, core material density ≥120kg/m³, achieving sound insulation of 25–35 dB(A), effectively blocking external and adjacent area noise.
Sealing strips and tenon-and-mortise structures are used at panel joints to eliminate sound transmission through gaps and prevent noise penetration through the seams.
2.Vibration-Damping Floor/Ceiling Design: Vibration-damping pads and anti-static flooring are laid on the floor, and vibration-damping hooks are added to the ceiling joists to reduce the transmission of vibration noise generated by equipment such as fans and air conditioning units.
A vibration-damping expansion joint is reserved between the clean room and the external wall, and filled with sound-insulating cotton to block structural resonance noise.
II. Material Noise Reduction: Enhancing Internal Sound Absorption
1. Application of Internal Sound-Absorbing Materials
Partial installation of microporous sound-absorbing panels (such as fiberglass sound-absorbing panels and perforated aluminum panels) on walls and ceilings, with a sound absorption coefficient ≥0.6, absorbs reverberation noise generated by indoor airflow disturbances and equipment operation.
Sound-absorbing cotton is pasted on the inner walls of the return air duct and plenum to reduce turbulence noise within the air duct.
2. Enhanced Sound Insulation of Doors and Windows
Cleanroom doors use double-glazed tempered glass with sealing strips, achieving a sound insulation of ≥20 dB(A); observation windows use double-glazed windows with a thickness ≥10mm to reduce the intrusion of personnel communication and external noise.
III. System Noise Reduction: Optimizing Equipment and Airflow Noise
1. Supply/Return Air System Noise Reduction
Select low-noise fans (e.g., centrifugal fans, operating noise ≤60 dB(A)), and install silencers (impedance composite silencers, noise reduction 15–20 dB(A)) at the fan outlets.
Optimize duct design: Use large-diameter ducts and low-velocity air supply (velocity ≤2m/s) to reduce airflow friction noise within the ducts; install guide vanes at duct bends to avoid vortex noise.
2. Auxiliary Equipment Noise Reduction
Install vibration damping pads on the bases of air conditioning units, FFUs (fan filter units), etc., to reduce noise generated by equipment vibration.
Use DC brushless motors for FFUs, with operating noise 5–10 dB(A) lower than traditional AC motors; simultaneously control the operating density of FFUs to avoid excessive noise from multiple devices.