How to Reduce Noise From Ventilation Ducts

sound attenuator

In an office & industrial environment, ventilation – Heat recovery Systems play a really important role in ensuring that dirty air leaves the premises while clean air circulates in.

However, ventilation systems can be quite noisy, creating an unpleasant environment, which is both distracting and uncomfortable.

Another consideration would be cross talk privacy. Ventilation ducts convey air but can also convey noise from one open duct to another
If you have a private office or meeting room that shares a ventilation system with other rooms within a building you need to ensure any conversations in one room cannot be overheard in a different room .

If you are planning on reducing the ductwork noise, and increasing privacy this post has you covered.

Here, we’ll focus on what causes duct noise and how you can implement noise control.
Ready to get started?

Possible Causes of ventilation duct noise

If you are interested in duct noise control, it’s definitely worth knowing where the noise is coming from.

  • In short, when air is pulled into a duct, it causes friction with its surface and can create an unpleasant noise that needs to be controlled.
  • Air noise can also be caused by airstream turbulence and the mechanical components in the duct.
  • Dirty and blocked filter media will increase resistance and will result in excessive noise 7 be detrimental to the systems performance
  • Poorly maintained fans will increase noise level
  • Poorly maintained fans can cause excessive vibration and noise but could also further damage the duct work and other components with this system

Basically, the older and more worn out your ventilation & heat recovery equipment is, the louder the noise can be.

If you would like to figure out if the noise your duct is making is normal or abnormal, there are online calculators that can help you work out your duct noise calculation.

How to practise good noise control

People working in offices & industrial environments that have heat recovery HVAC systems will be glad to hear that there are several ways to carry out noise reduction to create a more comfortable work environment.

Here are several solutions you can try:

Option 1: Reduce the sound at its source

Most HVAC systems that are poorly maintained will create excessive noise.

Fan vibration

  • Ensure the supply & extraction fans are balanced and are not vibrating
  • You maybe able to Install fan flexible connectors these ensure any vibration does not travel from the fan to the ducting

Option 2: Use circular sound attenuators

Possibly the best, most professional and reliable ways to reduce noise from ventilation ducts & reduce the risk of cross talk is to use a specialist duct noise reducer. Called circular sound attenuators, or silencers, these will decrease the sound transmitted throughout your ventilation ductwork. They are usually located near noise-generating areas such as fans and air-handling units, airflow generators, air dampers and fire dampers or between offices and rooms,
They do a fantastic job at reducing noise within your offices or industrial premises.

Option 3: Line the interior of the supply and extract grille boxes

Simply by lining the inside of you supply & extract grille boxes with Class O Self Adhesive Acoustic Foam Sheets will reduce noise levels and also reduce the risk of cross talk between offices and other rooms connected to your HVAC system

Option 4: Acoustic Aluminium Flexible Ducting

Another simple was to help to reduce noise levels and reduce the risk of cross talk contamination would be ensure any flexible ducting is Acoustic Aluminium Flexible Ducting
This has as an inner duct, constructed with 25mm fibreglass insulation, also helps to maintain thermal insulation and which acts as a vapour barrier.
The outer jacket of this acoustic flexible ducting is a spirally produced multi-layer aluminium/polyester laminated fabric which has been reinforced with a fibreglass

Option 5: Insulate your walls

To reduce air flow noise in a duct, you may wish to insulate your walls. This is because sound can easily travel from one part of your industrial premises to the next through thin and uninsulated walls. To create soundproof ventilation, you’ll want to use materials such as soundproofing insulation for your walls to create a quieter and more pleasant working environment.

Good practices on ventilation system noise control

With a few great ideas in mind, you’re now better able to work out your duct velocity noise and
soundproof your ductwork. Bear in mind, though, that not every option mentioned above will be suitable for your heat recovery (HVAC) system.

For example, if you have open-plan spaces, then insulating your walls may be a futile endeavour.

Your best bet and most professional solution is to use circular sound attenuators for greater peace of mind.

It’s important to ensure that you use professional solutions in professional environments that are both safe and conducive to your needs.

Conclusion

When it comes to reducing the noise in your ventilation ducts, we at Ducting Express know how important it is for creating a safe and productive work environment.

The vibrations emitted together with the noise can be highly counterproductive and can hamper your team’s productivity also the potential for cross talk contamination could have wider implications

Make sure you use professional solutions for your premises and take advantage of the powerful circular sound attenuators we offer to give your industrial facility a streamlined look while limiting the sounds and noises created by your ventilation ducts.

If you need any help in choosing the right solution for your needs, don’t hesitate to get in touch with us.