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A soundproof vent should be done in such a way that it dampens your house against outside noises while at the same time allowing sufficient air circulation in your home.
In this article, we’ll discuss different methods of air vent noise reduction for both forced air vent and above door air vent.
Soundproofing a room may seem like a never-ending task since there are many ways that sound can enter into or out of any room in your house.
You may have soundproofed your ceiling, walls, and floor only to find out that outside noise is getting into your house through the air vents.
How to Soundproof a Vent
As aforementioned, there are different ways to soundproof a HVAC vent. While you could easily buy a cheap air vent cover, they aren’t recommended because they tend to restrict airflow- hence defeating the primary purpose of having air vents.
This article illustrates different methods on how to soundproof a forced-air vent and air vents above you. Keep reading to find out more.
How to Soundproof a Forced-Air Vent
A forced-air vent easily allows unwanted outside noise to travel between rooms in your house.
To prevent the noise transmission and at the same time allow airflow, it’s important to build sound baffles around the air vents in the room where you want to control the noise and in the adjacent rooms where the vent ducts are connected.
While there are different types of sound insulation on the market, acoustical fire batts (AFBs) are good for building into panels, acoustic insulation in the walls, or any other place where there’s a structure or frame to support it.
Constructing Sound Insulation for Forced Air Vent
Get plywood and cut it into 18x12inches pieces with a circular or table saw. This will act as the front panel for the sound baffle enclosure.
Then, cut pieces of plywood as needed to create triangular side and required backs panels for the baffle enclosure.
Cut 6 inch long by 1 inch wide pieces of plywood strips
Cut a minimum 6 inch long by ¼ inch wide slots for every 2 inches apart or less of the front panel with a router or a saw. This small space will allow air to escape from the sound baffle enclosure.
Screw-in the plywood sides and back to the plywood front panel. You can use silicone sealant on the interior edges to ensure that the edges don’t leak.
Screw-in the 1inch wide strips to the outer side and back panels, so they flush with the top edge. The strips will help you attach the enclosure to the ceiling.
Cut an acoustic fire batt mineral wool panel to be 18×12 inches and insert it to the baffle enclosure so that it covers the slots on the front panel.
Its purpose is to block sound transmission while at the same time allowing airflow.
Screw the enclosure to the ceiling and apply sealant at the exterior edges where the enclosure meets the ceiling. Repeat this process for every air vent that requires a baffle enclosure.
How to Soundproof an Above-Door Air Vent
There are two ways to block unwanted noise from the above door air ventilation.
- Block the vent entirely
- Create a sound maze
a) Block the air vent method
The most effective way to dampen your vent is to remove the ventilation and place drywall over the vent hole.
That’s quite expensive and might cost you a fortune. Instead, you could remove the vent and fill the gap with gap filler like Great Stuff 157906 Insulating Foam Sealant and put the vents back on that it looks normal again.
However, there’s a big downside with this approach; your room will likely turn into a furnace during the summer.
The air vent is installed in your room for a reason. It’s designed to allow air to pass through so that the room can be efficiently cooled and heated.
b) Sound Maze
Creating a sound maze might take more of your time and money, as well. But the result will be a quieter room with sufficient airflow.
This method works by creating a mini-maze inside the ventilation using pieces of thin plywood with acoustic foam taped to the wood scraps.
The sound waves are then forced to zig-zag several times before they can enter the room, which significantly dampens most sounds.
- Glue/ silicone sealant
- Acoustic foam or cotton
- A saw
The only shortcoming with this method is the fact that it isn’t useful in blocking unwanted noise as the drywall method above. However it’s more efficient since you’ll still reserve ventilation in your room.