March 9, 2021
In the UK, it is widely acknowledged that 15 per cent of the population has suffered hearing loss, either as a result of a sudden exposure to loud noise or long-term exposure to machinery noise. A number of studies have shown that working in a noisy environment can cause irritation of the ear canal, muffled hearing and an elevated risk of developing tinnitus. This is when vibration pressure waves that are transformed into sound by tiny hairs in the ear are flattened by excessive noise, resulting in a continuous ringing in the ears. Adverse noise can also make it harder for workers to hear alarms, as well affecting concentration, both of which present a safety hazard.
As part of its responsibility for the wellbeing of employees, companies are obliged by law to take all necessary preventive measures to protect staff. In a factory or workshop environment, all machines generate some degree of sound and vibration. The average noise level for an industrial air compressor is 85 dBA. To put that into context, it’s higher than a phone's ringtone, which is around 70 dBA but lower than most headphones, which can go up to 110 dBA.
In accordance with the UK’s Control of Noise at Work Regulations 2005, employers must assess the risk to workers' health and provide them with information and training, if noise levels reach 80 decibels. When daily or weekly average exposure is up to 85 decibels, hearing protection must be provided and hearing protection zones introduced on the shop floor. In any event, workers must not be exposed to noise above 87 decibels.
Within manufacturing and engineering, compressed air is often referred to as the fourth utility, so improving its efficiency and performance, whilst reducing noise and energy consumption are key drivers for compressor development. A compressor’s noise level can be influenced by a number of factors, the most obvious of which is proximity to the workforce. For this reason, it’s common practice to isolate compressor equipment into separate and often, outdoor locations, remote from the point of use. Whilst this mitigates vibration and noise, it incurs cost and productivity penalties, due to air pressure drops as a consequence of the increased amount of pipework. For every additional one bar increase in pressure to compensate for this drop, there’s an extra power requirement of approximately seven per cent.
Similarly, ambient noise is influenced by the properties of the room that equipment is located in. Its size, construction materials and the presence of other machinery will all have an impact on noise levels. Whilst housing a compressor in a separate room reduces noise on the shop floor, this is not always a logistical option, especially in smaller factory units.
The solution is the installation of quiet compressors, equipped with either a full or a partial enclosure that absorbs sound and reduces the noise level to well below 80 dBA. Machines designed to meet this requirement, such as ALUP’s latest Sonetto range, can be placed right next to the point of use, as they achieve noise levels of as little as 61 dBA. This new generation of powerful, quiet, oil-injected rotary screw air compressors feature the very latest in air end design, which facilitates a market-leading 15% more in Free Air Delivery (FAD) output and a reduction in energy consumption of up to 12%.
Through the use of rotary screw technology, which greatly reduces vibrations, these latest compressors provide users with a dependable source of air. By combining anti-condensation oil heater, tropical thermostat and larger air receivers of up to 500-litres, a compressor can operate on very low duty cycles, without the issue of condensation forming within the oil. In manufacturing and workshop environments where there is a need for treated dry and filtered air, the refrigerant air dryer in ALUP’s new Sonetto versions delivers a 55% reduction in Global Warming Potential (GWP) over previous dryers. With industries under pressure to reduce carbon emissions, as part of the government’s ‘Net Zero’ roadmap, further innovations in oil-injected air compressors will significantly help to lower environmental footprints, whilst reducing costs for manufacturers and ensuring the safety of the workforce. It’s a win-win scenario.