If you are someone who has trouble getting adequate sleep because of the noise in the surrounding environment, we are sure you’re tried various techniques to soundproof your room.
Suppose you have soundproofed the doors, insulated the windows, and purchased the best soundproofing curtains, but you can’t get rid of that annoying noise. In that case, you may still be tired of the annoying sound that can travel from your noisy air vents. So don’t worry; we are here to solve this problem. In this article, we will explain to you in detail how you can soundproof your air vents. So, let’s get going quietly.
How to Soundproof Air Vent?
Inspect Your Air Vent

Most individuals skip this crucial step before soundproofing their air vents. Air vent soundproofing methods require a thorough understanding of the following:
- The air vent’s function.
- The form of the ventilation duct.
- The total number of surfaces and walls that are in the passage of the air.
- The material used in the construction of air vent
- There are two categories of air vents; the first is ventilation vents, and the second is heating, ventilation, and air conditioning (HVAC) air vents. Ventilation vents provide cross-ventilation between two rooms, and you can find them installed above the doors. On the other hand, heating, ventilation, and air conditioning (HVAC) vents are responsible for maintaining a constant temperature throughout infrastructure and are installed elsewhere.
Use Acoustic Foam

Recording studios, movie theaters, and other similar venues use acoustic foam, which is a sound-absorbing substance. In most cases, the foam in question is composed of components derived from polyurethane, such as polyether, polyester, and extruded melamine.
Its primary function, from its inception, was not to reduce noise but rather to increase the quality of sound produced within an enclosed space by reducing echo. However, because the walls of air ducts are typically composed of metals, minimizing the echo created by the bouncing back of sound can be a beneficial step in the process of lowering the overall volume of the noise.
The procedure to soundproof an air vent with acoustic foam is a breeze to follow:
- Using a screwdriver, remove the air vent covers.
- Then use a layer of acoustic form to cover the whole inside of the air vent.
- Use an adhesive to provide a secure attachment to the sidewalls.
- Now reattach the cover, and the shape will aid in capturing and decreasing the energy of sound waves, which will result in a reduction in the amount of noise that you can hear along the route.
Install Soundproof Curtains

To keep the temperature of the room stable throughout the hottest parts of the summer and to allow for ventilation within a closed space, air vents are often required. However, it’s possible that permanently blocking the air vent will result in more problems than it solves. The best option is to use a soundproof curtain or blanket to take care of this issue.
It is by far the most straightforward and most inexpensive method to lessen the sound vibrations that are flowing into the room via the air vents, and it does so without affecting the overall beauty of the space in any way. Furthermore, installing a curtain rail above the vent and then draping a heavy curtain over it is all that you need to complete this project. Therefore, it is not strictly necessary for the curtain to have soundproofing properties. For example, you can use a cover that is composed of material that is thick, dense, and layered and can be equally as effective in dampening the sound waves as a single layer of material.
Add Drywall

Up to this point, we have gone through the many methods by which you can create a sound baffle for return air without entirely compromising its functional capacity. However, if you are searching for a complete vent noise suppressor, for instance, in a music studio, you may begin by completely removing or sealing the air vent in the room.
This step may come in helpful, particularly for the vents that aren’t part of the HVAC system, providing heat isn’t a severe problem in the flat, and there is sufficient ventilation. The procedure of creating a silencer for air duct noise is not overly complicated:
- Open the air vent and then secure a wooden board at the very beginning of the vent so that its dimensions are the same as those of the air vent.
- You have the option of either filling the duct with insulation, such as drywall or gypsum or blocking the vent with another wooden board and then sealing it with drywall.
- When you have stuffed the vent, use some glue that is made specifically for walls to blend it in with the wall. After it has dried, using sandpaper to aid, combine it with the texture of the wall, and then paint it so that it matches the wall.
How to Soundproof Air Vents Above a Door?

The most typical location for vents is above a door. The door vents in a room can assist in lowering the temperature by allowing hot air to ascend and escape. Unfortunately, this implies that the air vents are entirely ineffective in blocking airborne sound. Here are some methods you can use to soundproof air vents above a door. They are different than the methods used for wall soundproofing.
Create an Air Vent Sound Maze

You may soundproof an above-door air vent without reducing its airflow capacity by creating an air vent sound maze. We can define a sound maze as an insulating system with open ends that allows air to move through while still absorbing sound. A saw, wood glue, ruler, screwdriver, acoustic foam, or cotton 1/4 inch thick plywood are the things you need to create a sound maze.
- Cut the wood into four equal portions, each section being a few inches shorter than the vent itself.
- Second, cover the wood planks with the cotton or foam material you’ve chosen, and glue them in place if you can.
- Place the first wooden plank inside the vent and adhere it to the wall of the vent with the adhesive you just applied to the plank’s end.
- Maintain a half-inch separation between the other three pieces of wood while adhering them with opposite-end holes to create a zigzag pattern.
Use a Sealant

If you want a quick do-it-yourself solution, you may try using a soundproofing sealant. This method isn’t quite as long-lasting as others, but it’s lightning fast and requires almost no effort at all. You can utilize this as a solution if you are interested in saving money and may, in the future, need to unclog the duct.
The soundproofing sealer is often a foam-based material that, once applied, expands and seals any gaps. It closes the gap much more securely, and it also makes them water-resistant. You can also use sandpaper to smooth the sealant before positioning the air vent cover.
Remove the Vent

You should only resort to this option if you are very sure that you want to remove the vent completely. Taking off the vent cover and then using some gap filler to fill in the area left behind is the most effective way to achieve this. After the material has had enough time to dry, you may replace the cover, and the space will once again resemble a regular vent.
How to Soundproof Heating Vents?

Install Duct Liners

Installing duct liners can be a very affordable and straightforward way of sound insulation, particularly if you do not wish to replace the system or if, other than the noise, there is nothing wrong with your existing HVAC system. Moreover, an insulating substance in duct liners absorbs the sound waves propagating through the inner walls of the air vents.
The liner duct is attached to the inner walls of the air vent and has a double-sided liner. It ensures that the liner does not send fibers of glass wool into the space while air is circulating through it.
Use Flexible Ducts

Because of its malleability, a flexible duct may significantly cut down on the quantity of sound that escapes from an air vent. However, even though they are beneficial for soundproofing, you should only use them when it is required to do so.
Flexible ducts absorb sound by creating bends within their structure. Because of this, it is considerably more difficult for sound to travel when the air is moving, as the sound is partially absorbed every time it reaches a curve in the path it is traveling.
The use of flexible ducts comes with the potential drawback of the ducts developing tiny cracks over time. These cracks allow sound to escape, reducing the soundproofing capabilities of the flexible ducts. Because of this, they should only be utilized in situations when they are essential, ideally in locations that are quieter so that sound does not enter the duct and travel.
Use Soffits

If you wish to soundproof air vents and ducts that are immediately accessible to sound, your only option will be the installation of sound-insulating soffits.
For soundproofing, a typical soffit would be constructed out of MDF and have an inside layer of insulation. Furthermore, since these types of soffits are particularly good at dampening sound, they are frequently employed in the construction of home theater systems.
Some people who are passionate about home theaters may even go to the extreme of installing additional layers of drywall with Green Glue (viscoelastic damping) in the spaces in between the soffits. It is a great option, but you should keep in mind that it is only essential for rooms that demand a high amount of soundproofing.
When you install a flexible duct within the soffit, the consequence will be the construction of a large number of bends, which will result in an even higher level of soundproofing for the air vent.
Final Words
In light of the wide range of people’s needs for soundproofing, each task requires a unique manner of soundproofing.
It does not matter how much time or money you invest in the process of soundproofing your bedroom; all of your hard work will be for naught if you do not pay special attention to the air vents. Using the methods outlined above, you can get rid of this bothersome source of the noise.
Decide on the best solution for your needs based on the amount of soundproofing required, the size of the area required, the amount of money available, and the quantity of effort needed. When a vent isn’t in use, you can entirely seal it off.
You are very close to entering the calm and quiet space of your dreams, and the journey is almost over! Also, you may rapidly finish soundproofing your home with these do-it-yourself methods, which do not require significant financial inputs or the assistance of a professional.
You can also check out detailed guide on how to soundproof a window.