How to Soundproof an Above Door Air Vent (a Return Air Transfer Grill)

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Air vents above the door in your home are a convenient and money-saving way to keep the temperatures down in your home without blasting the air con all the time.

However, one downside of above the door air vents is that they carry a lot of noise in from the other side of the door, which can be a real nuisance especially if it’s a bedroom that is next to a communal area of the home that’s filled with people or noise. 

We’re guessing if you’ve found yourself on this article then it’s fair to assume that this is a problem for yourself too and you’re looking at ways to solve it. 

Luckily, we’ve got some recommended methods for you to try to soundproof the above door air vent in your home, some of which are more temporary than others if you’re looking for a quick fix, whilst others offer a more permanent solution to blocking out noise.

How to Soundproof an Above Door Air Vent (a Return Air Transfer Grill)

6 Methods to Soundproof an Above Door Air Vent In Your Home

1. Block the vent using drywall

If you’re looking for a permanent solution to reduce the noise passing through to a certain room, then you could consider fixing some drywall in the space of the air vent above the door which will block the vent and hopefully blend into the wall so it looks seamless (sort of).

We’d recommend buying a drywall repair to make the process a lot easier for yourself and so you don’t have to pay for a professional builder to come do it for you. 

So if you want to install drywall in place of your air vent then follow these steps below:

  1. Remove the metal grate that is covering the vent
  2. Measure the dimensions of the space so you can cut your drywall to the accurate size
  3. Then cut your drywall to the dimensions of the vent space
  4. Fix the drywall at both ends of the vent with wall adhesive or using screws
  5. Once the drywall is secure you can plaster over it to make it look smooth and inconspicuous 

Before installing your drywall over the vent, you could even consider putting some insulating material like foam or wood inside the vent if there’s room to minimize the flow of noise as much as possible. 

2. Create a sound maze

If you want to block out noise from the room but don’t want to restrict the airflow of the room, then one of the best solutions is to create a sound maze for your vent. 

The sound maze method uses layers of insulation on both sides of the duct which helps to reduce the sound in the vent but allows the air to travel in a zigzag pattern so it can enter and leave the room.

The insulating material inside absorbs the sound and therefore minimizes it before it reaches the room. The more plywood pieces you install, the less sound that will pass through.

You can create a sound maze by yourself and you’ll need the following tools:

  • Acoustic foam material 
  • Plywood
  • A wood saw
  • A ruler
  • A screwdriver 
  • Wood glue

Follow these instructions to create a sound maze for your vent:

  1. Take measurements of the inside of your vent using a ruler or a measuring device
  2. Then, cut the wood into 4 pieces that are a few inches shorter than what the inside of your vent measures
  3. Take your foam material and stick it onto the plywood pieces (you can choose to cut it to the exact measurement of plywood or wrap it around, just make sure it’s properly fixed)
  4. Glue the end of the wood piece and fix it to the back of the vent about 1 inch from the opening onto the wall
  5. Repeat this process but attaching the other pieces in a zigzag pattern through the vent (1 inch between the pieces for good airflow)
  6. Then replace the grate with the vent

3. Do some home renovation

A permanent solution to this problem is to do some home reno on this area of your home to completely remove the air vent and then build a new wall in its place This is a costly solution but also one of the most effective ones.

We’d recommend getting a contractor in to do this (unless you’re skilled in this area of work) as you don’t want to cause permanent damage to your home by knocking through a wall that you shouldn’t. 

You may also need to bear in mind that this could make the room get hot in the summer months as it’ll limit airflow into and out of the room, so make sure you have other methods of keeping the room cool before you knock through the air vent and permanently restrict the airflow. 

We’d recommend trying some of our other methods to soundproof the above door air vent first as these are still very effective and it may not require a more permanent solution like doing any home renovations. 

4. Use soundproof curtains or blankets

Not everyone has the flexibility or freedom for some DIY methods for soundproofing an air vent, especially those who are renting properties and cannot make any adjustments to their home.  

That’s why using soundproof curtains or blankets is a good choice for renters as they can easily be removed and create little to no mess that could risk you losing your security deposit. 

Soundproof blankets are made with a fiberglass material which is great for absorbing sounds and therefore effective at blocking them from coming through into the room.

You could also use a moving blanket if you don’t have a soundproof blanket, however, they are not as effective at blocking noise as they’re more porous.

Soundproof blankets are very heavy, so the heavier the soundproof blanket you get, the more effective it will be at blocking sound. 

All you have to do is install a curtain rod above or over the air vent that the noise is coming from and then hang either a soundproof blanket or soundproof curtains on or over the rod to block out the noise coming from the vent. 

If you’d rather, you could use some nails or glue to attach the soundproof blanket or curtain over the vent instead of having it hang from a rod above the door. 

5. Use acoustic foam 

Using acoustic foam as a soundproof solution is also another temporary method that can easily be undone whenever you want. This is a good option for people who don’t always need the room to be soundproofed and will only need to do it for certain occasions. 

For those who have air conditioning or a heating system through the vent, then you’ll also be able to use this method as the acoustic foam can be removed wherever you want to turn your temperature system on. 

Just buy an egg crate pattern acoustic foam from Amazon (they make them in various sizes) and then you can use it to plug the vent wherever you want.

  1. Spray an adhesive material onto the back of the foam you’ll be using
  2. Then fold your acoustic foam in half until it becomes a size that is similar to that of your air vent
  3. Unscrew or remove the grate from the air vent and then begin cutting your acoustic foam to the dimensions of the air vent 
  4. Don’t cut the foam too small otherwise the gaps around the edges of the foam will leak sound through to the room. Cutting it a little too large is not an issue as the foam should bend whilst you try to fit it into place
  5. Put the foam inside the duct making sure that no gaps are around the edges and then reinstall the grate 

6. Use some soundproofing sealant 

If you want a less permanent solution that you can easily do yourself at home, then you could use a soundproofing sealant that is relatively inexpensive to get hold of in your local home improvement store. 

The soundproof sealant is foam-based so it will expand to seal all the gaps, so you won’t need to add excessive amounts otherwise it’ll be more difficult for you to remove it if you ever change your mind. 

If you do have an active air conditioning unit in your home, then you won’t have to worry about the sealant being affected as it is pretty airtight and resistant to water. 

This method is easily reversible if you ever want to unblock your air vent in the future to increase the airflow into that particular room. To do this, you’ll need to use a drywall saw to cut through the sealant foam until it is all removed again. 

  1. Using a power drill or a regular screwdriver, remove the vent grate on the wall
  2. Use some home cleaner or white vinegar and a microfiber cloth to clean the grate so there is no dust
  3. Begin applying your sealant to the duct slowly to avoid any gaps being formed as this will lead to noise still passing through into the room
  4. Once you’ve applied all your sealant, screw the vent grate back onto the wall 

What does the above door air vent do?

An above door air vent helps to increase the airflow in the room when there is an air conditioning unit running or if there is a furnace going. The above-door air vent also keeps the temperature in the room maintained and remains the same or similar to the other rooms throughout the home.

Above door air vents are particularly common in bedrooms allowing air to pass through when cool air is being blown into the room by the AC or a heater, otherwise, the room would become pressurized as the thin slot under the door is not large enough opening for a sufficient amount of air to pass through.

The room with an above door air vent is probably highly likely to get very hot during the summer months so the above door air vent will ensure it remains nice and cool, especially important if you’ve got a baby or younger children sleeping in there. 

Will soundproofing the vent prevent airflower between rooms?

When you cover or block an above door air vent with soundproofing material then you will be cutting off some of the airflow, with some methods offering minimal airflow but optimum soundproofing protection and vice versa.

If you still want to maintain some airflow then you should try to opt for less permanent solutions or materials that won’t completely block the vent and allow some air to pass through to properly ventilate the room.

It is something to properly consider as it could affect the comfortability of being in that room. If you’ve got central air in your home, then all of your rooms should be around the same temperature and the air vent above the door is pretty much useless and just becomes more of an eyesore.

However, if your home does not have central air then you’ll have to consider whether the lack of temperature regulation is worth it just to cut off some noise that is passing through. Maybe it would be worth your while to rearrange some of the rooms in your home so the noise problem isn’t as much of an issue.