What are Quiet Compressors?

Anyone who has previously worked in a noisy industrial environment appreciates the need for effective sound management. Depending on their type and relative size, some air compressors push the limit of acceptable decibels in the workplace.

For employers, it’s worth knowing that there are quiet compressors available, as well as methods to manage the noise emanating from existing compressors.

Workplace Noise and Worker Safety

People pick up sound vibrations inside the ear. Each ear contains tiny hairs that convert vibrations to sounds. Potential hearing loss occurs when exposed to loud noise, usually for extended periods.

Noisy environments may flatten the hairs inside the ear, which sometimes leads to developing tinnitus (1 in 10 UK adults have tinnitus) or hearing loss (approximately 1 in 6 people have hearing loss connected to noise exposure).

Any loss of hearing is usually permanent, making it’s prevention paramount in the workplace.

UK Regulations for Noise Control

Based on the UK Control of Noise at Work (2005 regulation), every employer is required to carefully consider worker safety relating to noise exposure. Of relevance is noise levels at 80 decibels – such as machine noise – in a working environment. 

Other distinctions are made, and regulatory requirements are enhanced, at still higher decibel levels.

To protect their workers, employers must offer relevant information, appropriate training, and equipment, such as noise-muffling headsets, earplugs, etc. This becomes mandatory at the 85 dB level, and above. 

Additionally, employers must provide hearing checks for company workers in environments that are this noisy too.

Therefore, attention paid to a reduction of machine noise is worthwhile.

Factors That Affect Air Compressor Noise

There are different factors relating to noise when operating an air compressor. These are worth considering earlier as a purchasing decision might change to acquire a quiet air compressor (or a silent air compressor) rather than one that’s noisier.

Here are some factors that affect air compressor noise:

Compressor Proximity – It matters where the air compressor is located relative to most on-site workers. If a compressor system runs mainly in an automated manner, locating it away from the main working area is beneficial.

Using soundproofing materials to deaden machine noise further reduces the decibels reaching other areas of the job site.

Compressor Room or Open Area – Installation in a plant room is a better option. Surrounding walls and additional soundproofing reduce distributed sound levels. It won’t, however, reduce the decibels inside the room for people managing the compressor.

This is where quiet air compressors are useful in reducing the noise problem at the source.

Friction – Some air compressors are noisier due to parts rubbing against each other. This is part of their design, but contributes to overall noise levels. Size and RPMs also have relevance: a small air compressor used to inflate tyres at a vehicle workshop is compact and produces high psi, with high decibels to match. 

By comparison, an Atlas Copco VSD+ rotary screw compressor or a scroll compressor has barely any moving parts, and are far quieter options.

Sound Dampening – Rubber isolation pads for smaller compressors to sit on and/or soundproofing wall panels decrease vibration noise and sound emanations. They can reduce the sound levels that carry across the job site.

However, this will only partially lower the decibels generated by one or more air compressors. Don’t expect miracles!

Power Source Used – Air compressors are either gas-powered or electric-powered. Electric ones are quieter than those relying on gas. This is because gas-based compressors use an engine to generate power to function.

Air Compressor Type – Not all models are low-noise air compressors. Some older models and types can tip the scales at 85 dB. Others are quieter, like the Atlas Copco VSD+ range, which is often below 65 decibels. 

Near the end of it’s useful life, there’s a good argument for replacing an ageing and noisy air compressor with a silent air compressor.

Choosing a Quiet Compressor

If you’re interested in low-noise air compressors, it’s necessary to steer toward quieter air compressor types from the outset. Otherwise, there’s a risk of selecting a type of compressor for its performance and only later discovering its noise level is too high.

Here are some compressor types, which are viable options for the best quiet air compressor:

Rotary Screw Compressors

The rotary screw air compressor relies on two elongated helical screws that turn in opposing directions. This creates air pockets, allowing air compression to occur. Whilst it’s highly effective as an air producer, the screws themselves do not make contact. This helps to avoid friction-related sound emanations.

There are both oil-injected and oil-free versions of rotary screw machines. This is relevant for industries that require oil-free compressed air, such as medical and other fields. However, from a machine noise standpoint, both operate quieter than most other compressors.

Modern larger air compressors, such as the rotary screw VSD+ GA compressors from Atlas Copco, don’t operate much above 62 decibels. Alternatively, their smaller, oil-injected screw compressors (G 2-7 models) are capable of up to 10 bar at only 67 decibels. 

Both allow workers to be closer to the compressor area and not necessarily need to wear hearing protection.

Scroll Compressors

When specifically looking for the quietest compressors, a scroll compressor is an easy recommendation that fits this category. These are considered ultra-quiet compressors because they are designed to operate quietly from the outset. While no compressor is silent per se, their internal mechanisms and design approach get as close as possible.

They will operate around the clock, making them suitable for 24/7 operations, and ones needing an ultra-reliable system. The downside to scroll compressors is that their CFM rating (cubic feet per minute of compressed air production) is lower than a rotary screw or other compressor types.

The Atlas Copco SF and SF+ range of oil-free scroll compressors is worth a look. They get down to as low as 53 decibels, depending on the compressor selected.

Getting the Balance Right

Whether needing an air compressor to supply air to pneumatic tools, paint sprayers, or for another purpose, completing demanding tasks with less noise is essential. Louder compressed air generating systems, like reciprocating compressors, are unrealistic when a low decibel rating is essential for your operation. 

To find the right balance between performance, tank size, and sound level, talk with our team at Anglian Compressors.