Air compressors are noisy. To reduce the decibel output level and protect employees, quieter compressors are preferred.
In the UK, less audible compressors are not marketed under a standard name. Therefore, compressors in this category are interchangeably referred to as quiet compressors, silent compressors, ultra-quiet, or noiseless.
Quiet compressors are becoming increasingly popular due to their suitability for enclosed spaces and smaller footprints.
As a basic rule of thumb, machinery operating below 70 decibels (dB) is less noisy. Some compressors are around 63 decibels, whereas a few smaller units are nearer to 45 decibels. However, commercial, high-output quiet compressors typically fall into the 60 – 70 decibels range. For comparison, this is roughly the loudness of a two-way verbal conversion.
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How Quiet Compressors Work
What are quiet compressors? They are compressors created to produce compressed air while emitting less audible sound during operations. Quiet compressors do not happen by accident. They are designed from the ground up to operate this way.
How is this achieved? A few different methods are utilised to obtain the desired result:
- Enclosed motors.
- Motor insulation.
- Soundproofing materials to absorb sounds.
- Rubber mounts and isolation pads to reduce vibration-related noises.
- Fewer moving parts to limit friction during operation.
- Overheating mitigation via non-fan cooling systems.
- Quieter air compressor type selection.
Selecting an air compressor with fewer moving parts naturally reduces sound levels. Good examples of this are the range of Atlas Copco rotary screw compressors and scroll compressors.
It is also worth noting that sound levels are not simply a result of engine operating rpm or compressor air output levels. While they play a part, they are not a significant contributor.
Benefits of Using a Quiet Compressor
Here are some benefits of a quiet compressor:
Improved comfort: avoid the unpleasantness of loud air compressors operating nearby. This leads to happier workers.
Reduced noise: noise pollution is reduced, improving safety and decreasing long-term hearing loss risk for staff.
Regulatory compliance: the UK Control of Noise at Work (2005) regulation requires companies to be aware of noise levels. A hard exposure limit of 87 decibels is mandated in the regulation, strongly encouraging businesses to stay below this level. Hearing protection is required in the workspace above certain decibel limits.
Lifespan: quiet compressors are modern and built to last. Less friction between components extends the lifespan of the equipment.
Quiet Compressors vs Traditional Compressors
Initially, quieter compressors suffered comparative performance shortfalls to traditional compressors. Fortunately, the latest quiet compressor models deliver outputs similar to loud compressors while operating at a lower decibel level.
Silent compressor technologies deliver longer lifespans compared to other air compressor types. Why is this? Because more exacting, innovative designs have improved durability. Materials are of a higher quality. Also, many compressors are intentionally designed to reduce friction, allowing parts to wear more gracefully than traditional compressors.
From an upfront cost perspective, quiet air compressors are a little dearer than their traditional counterparts. However, their maintenance is less involved and downtime is infrequent. The longer lifespan and ease of maintenance reduce the equivalent total cost of ownership.
Traditional compressors are outdoor workhorses or installed in specially created compressor rooms. Silent compressors are more adaptable – some are portable, and others are installed in smaller indoor spaces or noise-sensitive locations.
Need help with quiet compressor types? Talk with our experts at J LL Leach.
Key Features to Look for in a Quiet Compressor
Motor type: quieter model types are consistently either the rotary screw compressor or the scroll compressor. Both rely on fewer moving parts, creating less friction-based noise.
Decibel rating: the rating confirms the typical db level. Below 70 dB is optimal.
Tank size: larger tank sizes reduce the need to run the compressor’s motor. Intermittent, rather than continual use, lowers average sound levels.
Compressor size: the size of the complete air system, not just the compressor, must comfortably fit into the intended installation site.
Power system: gas-powered compressors are noisier due to their fuel source. Electric-powered compressors produce less workplace noise, which is better for certain environments.
Portability: portable units tend to be the quietest air compressors. However, their lower noise levels come at the expense of reduced airflow capacity.
Maintenance: oil-free air compressors require less maintenance. However, oil-based compressors are often quieter due to reduced friction.
Common Applications of Quiet Compressors
Where are quiet compressors most used?
Workshops and studios: professionals working in small workshops and hobbyists using air tools in their workshops need a quieter compressor because of workplace proximity.
Car workshops and garages: mechanics frequently use pneumatic equipment. Less air compressor noise is preferable in tight spaces.
Dental: air-fed dental equipment depends on air compressors. However, a quieter office is much preferred by their customers.
Medical labs and other healthcare settings: reducing compressor noise is beneficial in these sensitive environments.
Maintenance Tips for Quiet Compressors
Here are some maintenance tips for owners of quiet compressors:
Fittings and seals: air leaks are a concern for efficiency and add unwanted noise that requires elimination. Loose fittings and weak seals cause air leakage and potential rattle noise. Resolving these issues reduces the decibels from compressor system operations.
Lubricants: for oil-lubricated compressors, ensuring they have sufficient oil is essential to eliminate noise caused by friction. Oil-free compressors may use other lubricants. Keeping all lubricants topped up is beneficial for continued noise reduction.
Filter check and replacement: air filters ensure the motor evacuates hot air while benefiting from cooling systems. Clogged filters lead to engines pushing harder than necessary, risking overheating and creating a loud noise. Cleaning and replacing air filters prevents these issues.
Better installation: uneven surfaces create additional vibrational noises that are difficult to trace. An on-site noise evaluation helps to determine the actual causes of higher operational decibels than expected.
Conclusion
Noisier environments are dangerous for workplace health and well-being. The impact of noise pollution should never be ignored. Using quiet compressors lowers your overall noise footprint.
Quiet compressors crucially keep noise below 70 decibels because of sound dampening and reduced friction architecture. Recent improvements to silent air compressor technologies deliver similar power usage, airflow levels (CFM), and air pressure levels (PSI) compared to higher decibel compressors.
Choose the right compressor. Consider the specific use case, motor type, and decibel level requirements. Reach out to J LL Leach to explore the possibilities for quieter compressed air production.
