Controlling Diesel Generator Noise: What You Need to Know

Diesel generators are a lifeline for many construction projects that have no access to the electrical grid for power. They support projects with anything from lighting welfare rooms, to powering heavy machinery. Generators will typically run 24/7, which means outside of the site operating hours, including evening and weekends.

The noise from working generators emanates at very low frequencies and moves in waves that travel a lot further and through materials that high frequency sounds are not able to penetrate.

During the normal working day, generator noise is usually masked by general ambient noise, but generators are typically used to power critical applications that need to be kept going around the clock. Consequently, complaints can arise from those living and working nearby once the ambient noise drops, especially overnight. The low ‘throb’ of a generator is not only susceptible to being perceived as a nuisance, but it can also lead to serious health issues.

How Noisy is a Diesel Generator?

The key components that contribute to the noise is the engine, exhaust and cooling system. A good proportion of the noise from a generator is from the exhaust, which is typically sited on top of the generator itself.

The levels of noise coming from a diesel generator can vary depending on its size and capacity. For example, a smaller generator could create around 85dB, whereas a larger generator can create much larger volumes of noise, reaching around 105dB.

According to the hearing loss charity, RNID, “Repeated or long exposure to sounds at 85dB or above can cause hearing loss. If you work in a noisy environment and the sound levels reach 80dB, your employer should assess the risk to your hearing and give you information about this.”

This emphasises the importance of ensuring generator noise pollution is consistently at a safe level to protect workers and people living and working nearby.

Health Effects from Excessive Noise Exposure

Damage caused from noise exposure is related to the intensity, nature and duration of exposure. Some possible health effects caused from excessive noise exposure include:

• Noise Induced Hearing Loss
• Tinnitus
• Physical damage to the eardrum and ossicles
• Annoyance stress- Which is difficult to measure and quantify, but may cause psychological effects such as poor concentration, irritability and stress

Exposure to high intensity noise levels regularly can almost certainly produce some degree of noise-induced hearing loss in those whose hearing are susceptible. Anything over 80dB(A) can be classed as high intensity noise.

How Do Noise Control Solutions Help?

Noise control solutions reduce noise pollution through blocking the line of sight between the noise source and the people nearby. This is known as an ‘acoustic shadow’. An acoustic shadow is created when a physical obstruction absorbs a soundwave and prevents it from travelling. When soundwaves are absorbed by an obstruction, an ‘acoustic shadow’ is cast on everything behind it, reducing the level of noise that is heard in the ‘shadow zone’.

The below diagram shows how an acoustic shadow works:

Recommended Hire Solutions for Diesel Generator Noise

RVT Group have been supporting projects with noise control for over 30 years and are considered experts within our field.

The 3C’s®: A proven methodology, devised by the RVT Group, to ensure effective control of all on-site health hazards.

Capture the hazard - Position the acoustic barrier close to the noise source (fully enclosing it if possible) to maximise the acoustic shadow area.

Contain the hazard - Block the line of sight by ensuring the noise barrier is seamless. You may wish to consider whether an enclosure would be more suitable for fully containing the noise.

Control the hazard - Use high quality noise barriers, with high sound attenuation, to absorb excessive noise. Screening reflective surfaces like walls may also help to reduce noise bouncing the sound over the barriers.

We provide specialist noise control hire solutions suitable for a range of generators:

SOUNDEX® Generator Enclosure (PLF-Tech® low frequency technology)

Noise Reduction: Up to 59.9dB at 5000Hz | Up to 27.8dB at 1000Hz

Our SOUNDEX® Generator Enclosure has been specifically designed to attenuate the low-frequency noise associated with generators and includes a convenient access door for maintenance and refuelling.

Incorporating two layers of SOUNDEX® high-performance acoustic material, the SOUNDEX® Generator Enclosure is specifically designed to handle the low frequency sound from generators and other static plant.

Independently Tested & Certified Noise Control Solution

RVT Group had an acoustic test carried out on this equipment in a laboratory sound insulation environment, testing it to BS EN ISO 10140-2:2010 standard.

SOUNDEX® Generator Acoustic Enclosure | RVT Group

SOUNDEX® Machinery Enclosure

Noise Reduction: Up to 11dB at 1600Hz

This quick, easy assemble kit is ideal for short term hires when time is critical. It is easily transported around site if needed and is ideal for reducing noise during night work or in emergency situations. With a space allowance for the generators inside, it maintains safety and ensures protection against over-heating.

Soundex Machinery Acoustic Noise Barrier | RVT Group

SOUNDEX® Generator Exhaust Attenuator

Noise Reduction: Up to 18.9dB at 1250Hz

This hire equipment can provide effective noise reduction for generator exhausts and is a quick and easy to install. Manufactured with high-grade materials, it can withstand extreme exhaust temperature whilst being sufficiently ventilated to ensure there is no reduction in engine efficiency. This noise reducing solution can also be used to completely enclose smaller items of plant such as compressors.

Soundex Generator Exhaust Attenuator | Noise | RVT Group

If you have any noise concerns about your project, contact RVT today on > Book a Free Consultation | RVT Group alternatively, call us on 0808 281 3150.

We can you provide you with best practice advice and can visit your site for a FREE noise control survey, giving you assurance that you have everything in place to protect your workers, and the public.

For more information on acoustic shadows > Best Practice: Construction Site Noise | Creating… | RVT Group

Discover more about our generator noise solutions > Soundex® Equipment | Noise Control | Acoustic Barriers | RVT Group