Ventilation fans are widely used not only in industrial parks but also in the civil field. However, ventilation fans often cause very loud noise, so to ensure a sound environment and avoid noise pollution, soundproof ducts are the best choice.

So what is duct sound absorption? How is it structured? What types of duct sound absorbers are popular on the market? Why should we use sound absorbers in ducts? To answer these questions, let’s find out with P69 Mechanical Factory !

What is Duct Silencer?

Duct Silencer, also known as soundproof box, is actually a device placed in the ventilation fan that has the effect of reducing the noise emitted when the machine is in operation.

Similar to other types of soundproof flexible ducts, the sound absorber is composed of 3 parts: the outermost corrugated iron pipe, the middle is the soundproofing materials, and the innermost layer is the core corrugated iron.

Soundproof materials are used such as glass cloth, mineral cotton, vulcanized rubber…. Depending on the thickness and type of soundproofing material, the level of noise reduction is also different.

Duct soundproof boxes are used a lot in construction projects today. It is installed in the ducts, ventilation fans and used in construction works such as schools, hospitals, high-rise apartments…

Basic structure of Duct Silencer

Basically, the soundproof box will be composed of 3 parts. Detail:

• The outside is a corrugated iron pipe
• Mineral wool layer and glass cloth in the middle
• Perforated hole in the innermost

Types of popular duct silencer on the market

Based on criteria such as shape and size, the current sound absorption duct is divided into 3 types: rectangular duct soundproof box, circular duct sound absorption box and plate type duct sound absorption box..

1. Square, Rectanguler Plenum Box

Is a soundproof box designed with the old shape before and easy to use. The level of sound reduction of the box increases significantly as the thickness increases, the density of the mineral wool/glass wool layer increases and the distance between the sound-absorbing panels decreases.

For rectangular sound-absorbing boxes, when manufacturing, manufacturers often produce sound-absorbing boxes in many sizes and thicknesses of sound-absorbing panels to suit the layout and use purposes of the building.

2. Round Duct Silencer

It is a new line of wind-tunnel sound absorbers with good sound absorption, easy to install and operate, and save space. This is a new product line on the market today, so the number of manufacturers of this type is not much.

3. Plate-type Plenum box

As a sound absorption box with excellent sound absorption ability and for the frequency range of 500÷1000Hz, the plate-type ductwork has the greatest sound absorption capacity.

For plate-type sound-absorbing boxes, depending on the sound frequency, design ducts of different sizes. For low-frequency noise sources, large boxes should be selected and vice versa.

Why should we use silencer in ducts?

In today’s modern life, product duct silencer is being used popularly in many different spaces because of the outstanding benefits it brings. If in the past, sound absorption in air ducts was produced in the traditional way by using mineral wool, glass cloth, perforated corrugated iron to absorb sound, now it has been used with vulcanized rubber glued inside. The tube has an extremely convenient cylindrical structure.

Easy to construct

The advantage of duct silencer is that it is easy to install, quick to construct, and ensures extremely effective insulation, soundproofing and fireproofing features.

With excellent sound insulation, your space will be effectively limited noise, thereby not only ensuring the production process but also protecting the health of workers.

Effective noise cancellation

Besides the effect of preventing noise from equipment and machinery, it also has the effect of anti-noise by the aerodynamics of the airflow, against the noise of the airflow from the blowers, against the noise transmitted from outside sources. in the room and especially filter dust in the environment of factories, factories, industrial parks, commercial centers … out and bring clean air inside extremely convenient.

Compact design

The product has a compact design, does not take up a lot of installation space, has good sound absorption, … helps to save maximum space.

The products Duct Silencer in the ducts are suitable for many different spaces, providing a quiet space, ensuring production and business activities… which are extremely necessary for today’s modern life.

Disadvantages of Duct Silencer

Mineral wool is not really capable of absorbing sound at all frequencies. Use can be very effective, sometimes not effective at all, depending on the wavelength and frequency of emission.

Mineral wool after use will absorb water and lose its insulation effect as well as the ability to simultaneously produce mold and odor.

On the other hand, it is this mineral wool layer that, during use, will absorb water, losing its insulation effect, and at the same time, it will produce mold and bad odors that also adversely affect the health of the user.

Products like these are rubber in nature, so after use, they will decompose by themselves. At the same time, when a fire incident occurs, these products not only catch fire and spread, but also produce a lot of smoke and toxins (because the materials themselves contain CFCs, HCFCs, PVCs, etc.), so special endanger life. Most deaths are caused by smoke inhalation, not fire.

How to apply duct silencer to blower systems?

Use a soundproof box to reduce the sound emitted by devices and air flows into the room and to the surrounding areas.

For small devices such as fans, FCUs or AHUs: the devices are sealed with soundproof boxes to absorb the reflected sounds from the device and not let them spread around.

For large equipment such as Chiller machine room AHU, the equipment is placed in closed and soundproofed machine rooms.

For airflow: install duct mufflers in their path. The soundproof boxes are responsible for absorbing the sound propagated by the moving air stream.

Contact information P69 – M&E Contractor

Headquarter: No. 6/165C Xuan Thuy, Cau Giay District, Hanoi

Website: https://p69.com.vn/

Hotline: 02422121212 – 0965937799

Email: kd@cokhip69.com.vn

Facebook: https://www.facebook.com/p69nhathaucodien

LinkedIn: https://www.linkedin.com/in/congtyp69/

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