How to Eliminate Compressor Noise

Compressors are among the loudest equipment in any plant. Uncontrolled, they routinely exceed 100 dBA — well above OSHA's 90 dBA action level. Properly engineered silencers can reduce that by 25–40 dB without enclosures, acoustic barriers, or operational changes.

The Problem

Compressor noise has two primary sources — each requiring a different silencer type:

Inlet Noise

Air or gas rushing into the compressor creates broadband turbulence noise at the suction flange. Typically 85–105 dBA at 1 meter.

Discharge Noise

Pulsating compressed gas exiting the discharge creates tonal noise at the compressor's fundamental frequency and harmonics. Often the dominant source.

OSHA 29 CFR 1910.95 requires hearing protection above 85 dBA and engineering controls above 90 dBA. Many municipalities have stricter limits. Acoustic enclosures are expensive, impede maintenance, and trap heat. Silencers are the engineering solution.

The Solution: Engineered Silencers

Industrial silencers work through two mechanisms — reactive attenuation (expansion chambers that reflect sound waves back toward the source) and absorptive attenuation (sound-absorbing fill material that converts acoustic energy to heat). Most compressor silencers use a combination of both.

Silencer Selection by Compressor Type

Compressor Type	Dominant Noise	Recommended Silencer
Reciprocating	Pulsation (tonal)	Reactive chamber silencer — inlet & discharge
Rotary screw	Broadband + tonal	Combination reactive/absorptive — inlet & discharge
Centrifugal blower	Broadband turbulence	Absorptive splitter silencer — inlet
Roots blower	Strong tonal pulsation	Reactive expansion chamber — inlet & discharge
Vacuum pump	Exhaust pulsation	Absorptive exhaust silencer

Universal Silencers (Dürr) are engineered to order — each silencer is sized for the specific compressor flow rate, pressure, temperature, and target insertion loss. Standard catalog silencers rarely achieve the required attenuation; proper sizing is critical.