Editor’s Note: This post was originally published in 2016 and has been completely updated for accuracy, comprehensiveness, and new information.
It’s no secret – air compressors are excellent sources of energy. Not only do they power essential manufacturing elements and applications, but the heat generated as a result of the compressed air processes can be used as a byproduct that offsets other energy costs (get the details on heat recoveryhere). However, there’s another form of energy that is also a consequence of the air compression process – sound.
The sound we hear and the level at which we hear it is dependent on proximity to the source, as well as other variables in the particular environment. When indoors, these variables can include the size of the room, the contents of the room, and, in conjunction with various surfaces in the room, their ability to absorb or reflect sound. When sound waves come in contact with a surface, a portion of the waves are absorbed into that surface, while a remaining portion is deflected back. How effective a surface can absorb that sound is dependent on the material of which it is made – for example, think about how sound differs in a room with carpeting versus a room with tile or hardwood floors!
The Benefits of Reducing a Compressor’s Sound Level
Do you know the sound levels for various sounds that you hear on a daily basis? Sound levels are measured in units called decibels and is expressed as dB. Here are some common noises we hear daily and the typical associated decibel levels:
Leaves rustling – 30 dB
Normal conversation – 60 dB
Vacuum cleaner – 75 dB
ATV or motorcycle – 100 dB
Chainsaw – 115 dB
Crowd noise at a sporting event – 125 dB
Gun shot, fired at 100 feet – 140 dB
Compressor sound levels can range from 40-92 dB, with any noise higher than 85 dB being considered harmful with prolonged exposure. This means that reducing sound from air compressors and compressed air systems not only makes for a more pleasant and enjoyable workplace, but it is also healthier and safer for workers!
How Do I Reduce the Noise Level of My Compressor Installation?
The size of a compressor room, the compressors positioning within the room, and the associated materials of which the room is constructed are all important variables in determining and producing (and reducing) compressor noise. Vibration transfer through the compressed air piping system can also impact the transfer of sound throughout a facility. That’s why it’s important to fit a compressor and piping system with the appropriate vibration and sound insulators, or even enclose piping sections within a sound absorbing material, to help keep noise to a minimum. Many stationary air compressors also come equipped with integrated sound-reduction devices.
In addition to these items, here are four other effective means of reducing noise and making the workplace safer and more enjoyable:
Sound Insulation. This involves placing an acoustic barrier between the sound source and the receiver. This means that only part of the sound can be insulated, depending on the barrier and its individual characteristics. A larger, heavier barrier will obviously be more effective than a smaller one.
Sound Absorption. By surrounding the sound source with porous absorbents attached to a barrier, there is an added level of sound reduction beyond that offered by insulation alone; think open cell polyurethane foam or heavier cloth applications.
Vibration Insulation. By preventing the transfer from vibrations from one part of a structure to another, you can by association reduce the sound levels as well. One common area of vibration transfer is from a large piece of machinery through the floor. Steel springs, cork, plastic, and rubber are materials that are all effective means of reducing this transfer and any associated noise. The choice of material depends on the dimensions of the machine and surrounding space, as well as the stability demands of the machine. You should also keep in mind that if the compressor is installed in a location that has it coming into contact with another object, the noise generated by this contact can easily multiply.
Vibration Dampening. Fitting a structure with an external dampening surface composed of an elastic material is an effective means of reducing the machine’s vibrations (and sound). The thinker the dampening barrier, the more effective its means of reducing vibrations. This may prove to be the most cost-effective solutions, while conversely producing the most limited results.
This your compressed air system is too loud? It’s time to reach out to your local compressed air experts to find ways to make the work environment more pleasant for your workers!