Easy Way How to Soundproof Ventilation Air Duct Vents

Have you ever had an issue with unwanted noise issues coming from your heating and air conditioning ventilation duct? In this article, we will be talking about an Easy Way to How to Soundproof Ventilation Air Duct Vents With 1 Product!

To my surprise, I found it very difficult to find any information on how to soundproof an air duct vent. Everywhere I looked online was more in line with an air vent that only went from one room to another.

I wanted to find out about soundproofing an air duct vent that had forced air passing through causing all sorts of vibrations and noise. But first, before I find out how to stop the noise, I wanted to find out how the sound was even happening.

There are a few issues that can go on in heating and air conditioning ducts regarding unwanted noise.

  • These ducts have various pathways that airborne noise can get through.
  • The next noise issue is the vibrational sound. The vibrational sound is an actual physical movement. For example, when the car beside you pulls up with loud and heavy bass music, it feels like thumping, that’s vibrational energy.

Then there’s, of course, the interaction between the vibration energy and the airborne sound when the music is booming. It is definitely moving the ground because that’s what it probably feels like but it is actually vibrational energy. Vibrational energy is causing the air to move which is causing airborne sound transmission.

When you’re thinking about an air duct systems, most people think about the noise going through the ACE HVAC duct which is in one end and out the other end. What they don’t understand is that noise is trying to break out off the sides of the duct. Noise is trying to leave the duct the same time noise from all around the duct is attempting to enter.

1. Noise Reducer Silencer

Vivosun Noise Reducer Silencer

What you need to do right now is to stop looking at the air vent as the culprit. The culprit lies much deeper inside the ductwork than your outward facing air vent. Think of a car, what silences a vehicle from all the internal combustion going on? A muffler!

There is a product that you can now buy and install called VIVOSUN 8 Inch Noise Reducer Silencer (Amazon) for Inline Duct Fan.

The noise reducer silencer for inline duct fan seems like the answer. The vibrations are coming directly from the fan itself, and if you can dampen the noise vibration at the source, then the problem should solve itself.

The silencer is made from a thick, commercial grade neoprene foam. Inside is a specially selected open-cell texture combined with egg crate molded foam to deaden to vibration noise.

The thick foam insulation inside the noise reducer silencer stops sound waves yet still allowing clear air flow through the system.

The thing I found most amazing about this product is the fact that it was already fully assembled and ready to install. It easily connects with 6” fans, ducting or accessories.

I thought I would maybe have to hire someone to install it but it was rather easy and is also maintenance free. You install it and forget about it and soon you’ll hopefully also forget about the annoying noise that was coming from the air ducts.

You can get the Vivosun noise reducer silencer for inline ducts in 3 sizes. All you need to do is find out what size is the right match for your home air system.

  • 4 inch: 4″ flange diameter x 12″ body length (1.6″additional flange length at each end) and weighs 2.9 pounds.
  • 6 inch: 6″ flange diameter x 18” body length (1.6″ additional flange length at each end) and weighs 5.75 pounds.
  • 8 inch: 8″ flange diameter x 24” body length (1.7” additional flange length at each end) and weighs 9.3 pounds.

One thing to note is that this silencer does not have any mounting kit, it is assembled to be installed between the fan duct and the rest of the ductwork.

You could, however, wrap the silencer with metal or nylon straps in order to attach it to the ceiling. The ducts going into and out of the silencer will have to be approximately two inches out from the ceiling in order to connect to the unit.

Also, the silencer does not have to be directly beside the fan. Some ductwork has a curve right after the fan before it straightens itself out into the basement ceiling.

You need to find the nearest location to the fan that you can securely attach the noise reducer silencer to do its job. Doing it this way might not reduce the noise as much as if it was connected beside the fan but it will certainly help in giving noise reduction from the fan.

A popular question I hear about these silencers is assuming the fan and filter inside grow tent, where do you install the silencer? Inside (after the fan) or at the end of the exhaust duct?

The noise reducer silencer for inline ducts is designed to go after the fan. It is usually directly after the fan but you could place it further along the duct; if placing it beside the fan is impossible.

Note that the noise reduction will be noticeable only at the end of your duct where the air exits, not in the room with the fan itself. It muffles the air in the duct so that when it exits the duct, there is much less noise escaping in the air.

You can also attach the silencer Inside the grow tent in the direction of the air flow. You then attach the ducting to exhaust out.

2. Advanced Acoustic Vent

Advanced Acoustic Vent

I’ve personally never tried this product and also don’t know anyone that has but It is too bad you cant buy it from Amazon USA or Canada because it would be something I would be interested to try. It is currently only available on Amazon EU and from the brands website. but you might find this product at your local hardware store.

As you can see from the photo, it looks just like a regular air vent but has acoustic noise reducer built into the unit. Acoustic Air Vents have been designed to allow ventilation through a wall; fitted with a sound absorbing lining that considerably reduces noise penetration through the vent without reducing airflow.

This item is a bit more expensive than the muffler type silencer that installs directly after the fan. The acoustic air vent would only protect one room in the home from unwanted noise coming from the air vent.

For that reason, I would much rather install something that would reduce the air vent noise across the entire house. But, if you’re only concerned about one room and you live in the UK, you might want to give this item a try. If you have an item such as this one, please leave a comment below and let us all know how you like it and if it works well.

3. Updating the Entire HVAC System

This is not the news that some people want to hear, but updating the HVAC system might be one solution to getting everything back on track. Working with any type of soundproofing material might provide some temporary solutions, but nothing is quite like upgrading the entire system.

Modern systems do a much better job of controlling sound right away, and they are working much more efficiently as well. Even if an older HVAC system is working relatively fine, it still might be putting out a lot more effort to get the same results. It just ends up being very clunky, with one repair after another needed later on down the road.

The upfront cost is something that definitely makes people a little scared, but there are benefits to upgrading in the end. For example, new HVAC systems are much better at being energy-efficient, so a person will save a little bit on utility bills each month. That starts to add up, and people can begin to make their money back. It might not be a huge amount of money, but it does end up helping.

4. Air Ducts with Flexibility

Can a flexible duct actually help? Believe it or not, it is very beneficial for some situations. A flexible duct does a great job of cutting down on sound leaks, and that makes the job of the air vent that much easier.

The reason why this is only a solution for some is that flexible ducts are more susceptible to breaks. If something like that happens, it makes things very noisy, and it is not the easiest fix. Some people look at the flexible ducts and only do it when necessary. That means fitting in a unique situation, or utilizing the available room.

5. Using Soffits

Sound insulating soffits help with air vents and ducks. As long as the right materials used, people can see a pretty big sound reduction in a short amount of time.

Soffits became very popular when people started putting theaters into their home. It is made out of MDF, with insulation included. They can either be used alone, or by using additional layers of drywall between the soffits. It is a more advanced option than that everyone is going to feel the need to invest in, but it is certainly worth exploring.

Air vents and ducts are certainly a nuisance, but they are still essential when it comes to any type of room out there. The last thing a person wants to do is blow off the opportunity to control sound, so soffits might work.

6. Using Sound Baffles

A sound baffle is another option for people to explore if they need soundproof an air vent. A baffle is essentially a box, and it makes sounds travel a little longer to help with the overall absorption process. The sound is greatly reduced once it reaches people inside the room, and it might just be a solution that works for some.

This material goes into the inside of the walls, and vibrations are reduced greatly. Think of a sound baffle in a lot of the same way as a muffler on a car, as it can greatly change how sound travels.

Baffles are only going to help people who are using an HVAC system. The ducks are already pretty long, so there is an opportunity to install these baffles along the way. A more standard air vent won’t have the space, so the opportunity to have an impact is not going to be there in the end.

Should you Hire a Professional to Make your HVAC System Quieter?

There are so many different options to explore with soundproofing air duct vents that it is impossible to say whether or not it is for professionals only.

There are some simple solutions that just about anyone can pull off, and it does not make much sense to invest in a professional to help. However, there are more complex situations, and taking it extra time to get everything figured out is essential.

A professional will be able to identify the problem and little easier, and have long-term effects. If the news seems bad initially on what might be causing the problem, a professional opinion can help.

Another advantage to using a professional is that they can really make sure that a room is a soundproof as possible with other solutions as well.

If a person is having problems with an air vent, they may be having problems elsewhere in the room as well. Having someone who can do everything at once is going to help reduce stress and get things going in the right direction faster than ever.

What Causes Air duct Vents to Become Noisy in the First Place?

A lot of people like to troubleshoot what exactly causes air vents to become noisy in the first place. There are a few factors, such as the shape, the number of walls, and what material is used to make the air vent.

Some people in older buildings might feel like the entire setup needs replaced if it is severely outdated. If there is any damage, it also might make sense to help with soundproofing the air vent in the first place.

Try to stay away from metal material that might cause the sound to bounce off the vent and continue to be a problem. The fewer metal walls inside the vent, the better, because it will not travel quite as much with noise. A lot of the modern vents have this setup, which definitely comes in handy.

Finally, look for an extremely flexible duct that has bends so that the sound can’t travel quite as much. The more corners the better, especially when controlling the sound. Send sound on a bit of a maze, and everything will come out sounding a lot quieter in the end.


Thank you for reading one of our noise reducing articles. Reducing air vent noise can be difficult to figure out when searching online. That’s the reason why I decided to write this article in the first place. Please leave us a comment if you have a noise reducer silencer for an inline duct.

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