Air vents are great for letting air into the home. At peak summer, many apartment owners are grateful for them. However, they also allow noise into the home, which can be a great nuisance.

So, if you are looking for a way to prevent external noise effectively, you can try soundproofing. While several wrong soundproofing pieces of advice are out there, some methods are genuinely effective.

This article will explain how to soundproof vents. We will describe several options and the process of installing them. This will increase the overall comfort of your home.

Your Vents and Noise

There are two types of vents in most homes; the HVAC vents and the standalone/ fresh air vents. Fresh air vents have built-in spaces that allow natural air into the house.

Because vents have holes in them, they also carry noise. Noise is airborne. It travels through the air. This works similarly to open windows and doors; the more holes or space there is for air to come in, the more space noise will travel through.

This type of noise is referred to as flanking noise. Vents are usually made of different materials, but the most common are metal vents. Sounds bounce off of metal vents, which produces more noise. Metal vents are also more likely to cause echo noise.

Inspecting Your Vents

Some vents produce more noise than others due to the materials, shape, and placement. For example, if your neighbor’s vent is directly opposite yours, you will likely hear direct sounds from their apartment.

So, when you decide to soundproof your apartment, one of the most important things is to inspect the vents. This can give you a good idea of what soundproofing method will be the most effective for you.

First, there are three things to note.

• The material of the vent
• The shape of the vent
• The number of walls (structure) inside the vent.

As mentioned above, a metal vent is likely to produce more noise than other absorbent materials, so you’ll usually need a more robust soundproofing method than simply putting up some curtain layers. Likewise, if two vents with straight and large holes face each other, noise and air travel faster.

However, if there are more corners with a lot of bends, less noise reaches the end of the vent. Also, vents with more holes and blocks may prevent noise better than those without walls.

How to Prepare for SoundProofing

Soundproofing your vents is a relatively easy job. However, you should still prepare for the soundproofing work ahead.

• Clear the area surrounding your vent of any furniture or household items.
• Get a ladder or high stool if your vent is on the ceiling. You can use a pillow for your knees if it’s on the floor.
• Use a screwdriver to remove the screws of the vent’s metal grate.
• Inspect the structure of the vent with a flashlight. This will give you an idea of how susceptible your vent is to noise and the best way to soundproof it.

How to Soundproof Vents: Top 6 Effective Methods

You can only wholly prevent sounds if you block off your vent completely. Usually, most soundproofing methods reduce noise levels to as minimal as possible.

We will discuss them below.

Block off the Vent With a Drywall

The most effective method to completely block off the noise, or even prevent noise from going out, is to convert the vent to a wall. For example, if you are a sound technician working from your apartment, you can eliminate noise entirely by removing the vent.

This method may be helpful if you don’t have to worry about working air conditioning and have multiple windows. Here’s how to go about it:

• Remove the vent covers.
• Fill the ducts with wooden studs
• Close it off with drywall.
• Seal the area around the drywall with adhesive.
• Sand the area and wipe it clean till smooth.
• Paint or cover with your wallpaper.

The downside to this method is that condensation will gather if you have active air conditioning and seal your vents. This may eventually cause severe mold and mildew problems, which can damage your health.

The Sound Maze Method

A sound maze is a noise reduction system that allows sounds to bounce off multiple surfaces and travel a longer distance before entering a room. When this happens, the noise uses all its energy and has way less impact when it finally enters the room.

Sound mazes are great because air still circulates efficiently, but only the sounds are effectively trapped. Sounds mazes utilize two primary materials:

• Acoustic foam to deaden sound waves.
• Plywood dividers to bounce out sound waves.

How to Make a Sound Maze

First, collect all the materials you need in one place. They are:

• Plywood
• Acoustic foam
• Green glue
• Measuring tape
• Stanley knife
• Mini wood saw
• Screwdriver

Here’s a step-by-step of how to build a sound maze.

• Use a screwdriver to remove the vent covers.
• Measure the internal size of the vent and cut the plywood board to fit that size.
• Cut off a small part of the top of the plywood panel for air to travel through.
• Make about 3-5 more plywood inserts, as much as the vent can contain.
• Cover both sides of each panel with acoustic foam to prevent echoing.
• Glue the edges of the panels in place inside the vent.
• Leave an inch between each panel to increase the soundproof effect.
• Reattach the air vent covers, and that’s all!

Install Soffits

If your air vent is directly exposed to the source of sound that travels into your home, installing soffits is one of the most effective ways to reduce noise.

Soffits can be made from several materials, but the best material for noise reduction purposes is MDF. They allow air to enter at a minimal level and have a layer of insulation built in. Soffits are commonly used in cinemas and studios because they are effective.

Installing a flexible duct in the soffit will help create more bends. This will reduce the impact of any sound before it reaches your room.

Use Soundproof Curtains or Covers

The simplest way to soundproof your room is to get a soundproof curtain. This solution is great because you can ensure that your vent gets maximum fresh air into your home by raising the curtains. You can let air in at peak summer and drop the curtain or covers during winter.

Still, a curtain won’t block air from coming into the room. It’s up to you to decide when either air or noise is the priority. The good thing is, this process requires minimal work and even adds to the aesthetic appeal of your home.

Soundproof curtains are usually densely woven and thicker than normal ones. You can install a curtain rod above the vent or along the ceiling line so that it reaches the floor.

Even if you can’t find a soundproof curtain, you can get any extra thick curtain or cover. You can also hang grommet blankets.

However, if your vent is on the floor, it’s best to use furniture to cover it. For example, you can place an arm sofa or ottoman in the area where the vent is.

Use an Acoustic Sealant for the Opening

Using an acoustic sealant is another excellent way to seal up your vent. This method only takes a few minutes. Foam sealants block off the vent and can minimize both the air and noise getting in. They expand when applied and become air-tight when dry.

When you block off the vent, you can paint and spray over the area to look like an ordinary wall. One of the best acoustic foam sealants is the Great Stuff Big Gap filler. Ensure you measure your vent area to know how much sealant you need.

Here’s a step-by-step guide:

• Don on your gloves and mask.
• Remove the vent covers with a screwdriver.
• Fill the entire vent space with the acoustic sealant.
• Wait a few minutes for it to spread and dry.
• Place the vent grates back in position.

Shut the Vent Grate

If there’s an abnormal noise level coming from your vent, then chances are that it’s also preventing your room from heating or causing a draft. In this case, the ideal solution is to put a temporary plug on it.

You can create a plug out of the grate cover.

First, you need a quarter-inch thick piece of plywood. You’ll need to measure the inside of the grate and cut out that measurement from the plywood. Then place the plywood inside the grate and then screw the grate back in place.

Final Thoughts

Every noise situation has its own needs. So, before choosing a solution on how to soundproof vents above, you should consider your case properly.

If your home needs the air, you can opt for a sound maze or a temporary solution like hanging a soundproof curtain over the vent. On the other hand, blocking off the vent may be the ideal solution if the noise is unbearable and you have up to two windows in the room.

These methods may not completely solve your problems, but they can make a huge difference. Keep in mind that it’s always best to consult a professional if these methods don’t resolve the issues that you are facing.