Diesel generators have become widespread in commercial, industrial and urban settings. They are considered to be one of the most reliable sources of alternate power in case of a planned or unplanned power outage. Their ability to perform in all kinds of weather, efficient performance, cost-effective fuel consumption and robust power supply makes them a popular choice in power-significant establishments.
However, diesel generators, as compared to other kinds of generators, are known to produce more noise which could be a distraction and a nuisance for the people around. This could especially become a nuisance in urban settings.
To reduce this noise, diesel generators come fitted with silencers or generator mufflers that perform the same function for combustion engines as mufflers do for engines in automotive or construction applications. Their main purpose is to reduce noise and exhaust emissions that are produced during the process of combustion.
Importance of Silencers in Diesel Generators
Most engines come with a silencer that reduces the overall noise generated by the engines. Without these silencers, the constant noise generated by the engine during the entire duration of its running will cause unbearable discomfort and distraction for the people around.
The same is the case with diesel generators. In industrial or commercial setups, the generators might be required to run for long hours, and the noise they produce can lower the productivity of the workers. In urban, residential setups, the unbearable noise can irritate the owners and the neighbors alike, making it rather difficult to use it for the duration when the power is off.
The only solution to this is to use generators that come with high-quality silencers or generator mufflers that bring the noise down to recommended levels so that the generators can be used without disturbing or impacting people around.
Generators producing high noise levels will not only create noise pollution but long hours of exposure to such noise can also impact the health of the people around them by causing stress, tension, and many diseases. Using low-noise generators with rightly fitted silencers means that you are aiding both of these factors.
Diesel Generator Silencers – How they Work?
Diesel generator silencers are essential components of the machine that reduce the noise to bearable and recommended levels. While some silencers do this by absorbing the sound waves and then releasing them at a much lower level of energy, others let the noise bounce from one chamber to another and thus reducing the overall noise that flows out of the generator chamber.
There are three basic types of silencers:
Reactive Silencer
In these generators, the internal construction consists of a maximum of three chambers that are connected through a pipe. The exhaust noise created bounces between different chambers and the amount of noise that finally comes out of the exhaust is reduced to a considerable level. Reactive silencers are commonly used for low to mid-level noise reduction.
Absorptive Silencers
These kinds of silencers have internal construction with fiberglass or E-glass insulation. The exhaust noise is reduced as it passes through these insulations that absorb a large part of it. These kinds of silencers are used to reduce high-frequency sound waves.
Combination Silencers
These generators, as the name suggests, come with a combination of reactive and absorptive silencers type construction. The absorption material is fitted inside the chamber design of the reactive silencer, considerably reducing the noise. These silencers reduce mid, low and high-frequency sounds.
Type of Silencers
The above-mentioned functioning of silencers provides a wide variety of silencer types that fulfill different sets of needs. You must choose the one that perfectly fits your requirement based on the model of your generator and the level of noise it creates. Following are the type of silencers you can choose from:
Cylindrical Silencers
These silencers are the most common and widely used type of silencers that can be utilized in a variety of applications. They are highly versatile as they can be mounted both horizontally as well as vertically, making them a popular choice for generators of various different models. Cylindrical silencers are also quite affordable compared to their counterparts. So, all those who have budget constraints can opt for these. They also make for a perfect fit for both indoor and outdoor applications.
Low-Profile Silencers
Low-profile silencers are made to be space-specific, which is why they are available in different kind of shapes including rectangular, oval, and round. These silencers must meet the National Fire Protection Association (NFPA) guidelines as they are mostly used at sound attenuated enclosures.
For a generator that operates in a combustible atmosphere, changes are a must in the exhaust system to make sure that the sparks generated during the combustion process do not emit into the atmosphere outside.
The silencers that capture these sparks are called spark-arrested silencers. They are usually cylindrical in shape and come in a modified reactor design. This design pattern lets the sparks circulate within the silencer and eventually drop into a collection box. This collection box must be kept clean and tidy at all times to ensure the smooth functioning of the system.
Furthermore, the exhaust gases that emit during the combustion process can reach temperatures up to 1400 degrees Fahrenheit. Since most of these gases are released into the atmosphere, heat recovery silencers are used to handle the situation. They utilize the heat generated from the exhaust system before being released into the atmosphere. This heat can be used for any system that requires heat from an external agency.
Emission Control Silencers
During a combustion process, different kinds of gases are produced. While some of them can be harmful to humans and the environment, others can be harmless too. However, to handle the entire situation, the Environment Protection Agency (EPA) has charted out specific guidelines that must be followed by those using combustion process machines.
These silencers work by reducing the amount of noise produced by the engine by absorbing it and then redirecting it away from the engine. Certain models of emission control silencers come with the ability to control the vibrations as well, thereby leading to an overall quiet operation.
Generator Silencers
Attenuation Silencers
These silencers are specially designed to reduce the overall noise created by the diesel generator engine. Sound attenuation silencers absorb and dissipate the noise before it is released from the engine into the outside world. These silencers are widely used in generators used in residential areas.
Hybrid Silencers
These silencers provide a dual purpose. They combine emission control and sound attenuation all at once and hence are quite productive and useful. They are mostly used in places where both emission and noise reduction are strict requirements.
Sound Ratings – Generator Silencers
The sound intensity that a generator produces is measured in decibels (dB). It is a measurement unit that is used to express the ratio of a physical property to another. This is represented on an algorithmic scale. Initially, the silencer ratings we divided into four basic grades – industrial, commercial, residential, and hospital grades. The sound reduction of silencers varied greatly during this time, which is when Electrical Generating Systems Association (EGSA) came up with a rating guide charting out consistent silence ratings for all manufacturers who were a part of the association. These ratings became the standard ratings now followed by all. These are:
- Industrial Grade – Exhaust noise reduction of 15 to 20 dBA
- Residential Grade – Exhaust noise reduction 20 to 25 dBA
- Critical Grade – Exhaust noise reduction of 25 to 32 dBA
- Super Critical Grade – Exhaust noise reduction 30 to 38 dBA
- Hospital Grade – Exhaust noise reduction of 35 to 42 dBA
- Hospital Plus Grade – Exhaust noise reduction of 35 to 50 dBA
- Extreme Grade – Exhaust noise reduction of 40 to 55 dBA
- Super Extreme Grade – Exhaust noise reduction of 45 to 60 dBA
See related: Site planning for industrial generator installation
Maintaining Tips for Reduced Noise Generator Functioning
For any machine to run smoothly and efficiently, it is necessary that it is maintained and serviced properly. The same applies to the diesel generators as well. To ensure smooth functioning, you must regularly check the oil level, air filters and spark plugs.
If the generator is maintained well, it will also help in keeping the noise level low. An ill-maintained generator will vibrate more, generating more noise. This will not be controlled by silencers either.
See related: How to prevent diesel fuel contamination.
Tips for Further Minimizing Generator Noise
While silencers are supposed to reduce the noise produced by the generators, if you follow these tips, you can further reduce the noise as you work/live around a working generator:
- Buy a generator that fulfills all your needs
- The exhaust pipe must be kept in the other direction or upwards
- Install your generator farther away from your establishment
- Place it on a soft surface
- Use sound deflectors
- Built a muffle box around the generator
- Use water as a muffler
Generators are highly desirable and useful reinforcements during a power outage. However, they can be extremely noisy. Silencers make it possible generator noise bearable.
If you still have any doubts or questions regarding silencers in generators, or simply want to know more about our collection of new and used generators, please feel free to get in touch with us!
Frequently Asked Questions About Generator Muffler
What is the function of silencer in generator?
In the world of generators, a silencer performs the same function for combustion engines as the muffler does for engines in automotive and construction applications. Both reduce noise and exhaust emissions produced during combustion.
Can you put a silencer on a generator?
A generator slip-on silencer suppresses noise from the generator. They stop the generator’s noise at the source—its duct fan, which creates loud vibrations as it works. Buy a silencer that’ll fit your generator; they’re made for both larger and portable generators.
