One of the biggest mistakes I see a lot of folks making when soundproofing their home or office is they forget about soundproofing the air vents.
If left out, air vents can result to unwanted noises coming through the ventilator. Regardless of how your home is soundproofed- and the air vents are not sound dampened, the noise will still get through.
The importance of good ventilation/ Air Vents
Ventilation systems play a crucial role in our homes. A good vent prevents air pollutants from affecting our health being. Additionally, a good ventilation system is capable of getting rid of unwanted smells from pets and cooking and also prevents the growth of molds.
Ventilation controls the amount of moisture in your home. If your house is properly ventilated, all your walls, wood structure and floors will stay dry.
Wood is prone to moisture and can easily rot when exposed as well as drywall. If moisture builds up in your house, it will not only destroy structural units but also facilitate mold growth.
If you’re exposed to mold for a long time, it can cause immune system problems and damage respiratory organs and cause asthma.
Reasons why soundproofing the vents is important
Soundproofing also known as isolation is very important for a number of reasons. The mostly common reason is to stop unwanted sounds from bothering people in the other for a peaceful and quiet home.
However a more important reason why sound isolation the vents is important is to stop sound from getting into the room.
Health and safety: Too much noise is not only bad for the environment but also for humans as well. Human bodies are not designed to withstand excessive noise as it can affect health and wellbeing of a person.
But why is this major reason?
Let me give you an example of a recording room. It’s important to prevent sound from contaminating what is being recorded.
Now that you’ve understood the reasons why soundproofing the air vents is important- let me the different methods to go about achieving that.
Does Soundproofing the Vents affect airflow?
The answer is YES. If you soundproof the vent, be ready to have low amount of airflow. This is because sound travels through the air and soundproofing will make prevent air from travelling- so airflow will be affected.
So before you can begin with this process- it’s important to have a clear set of goals. How much air does your home/room need and how much sound coming from the vents can you tolerated?
Only after you’ve got the right answers to these questions can you decide the best technique for your home. Here’s an example:
You can completely block the vents and pretend nothing was there or you can alternatively choose a method that will allow sufficient amount of airflow and also keep the vent noise down.
Remember that a peaceful and quiet environment brings about improved mental and health status and so does one with sufficient air circulation. Living in a quiet and peaceful environment with no air circulation will do you more harm than good.
You’re likely to find air vents in older homes built before the age of complex heating systems and air conditioning systems.
How Does Sound Travel?
To better understand the basic concept of soundproofing vents, lets first see how sound travels. Sound travels into different ways-
Through air: Meaning sound travels through holes in a room like switches, outlets, HVAC ducts, lights and gaps.
Sound travels through structures: meaning it vibrates through ceilings, walls, and tin ducting.
The very first steps in installing sound proof vent covers
The first step in soundproofing the vents is inspecting ventilation. Take note of the shape of the air duct, the obstacles inside and the material it’s made of. You will need ladder and a flashlight to peek through the grills.
The causes of vent noise
- The shape of the duct that connects two vents directly is incorrect.
- If the material used in the air duct is a metal, there goes your problem. Sound will easily bounce off the metal surfaces and reach your room in no time.
- If the number of walls the sound is bouncing off is too low, there goes your third problem.
Now that you’ve inspected your air vents and pointed out the culprit, let’s have a look at some of the methods you can address the problems found.
Guide: How to Soundproof an Air Vent (Normal Vents)
1. Block the vent for good using drywall
This is one of the most effective methods I would recommend for anyone wishing to get rid of the vent noise once and for good. While it’s effective, it’ll take much of your time and effort to effectively implement it.
The first step is to fill up the duct and add drywall over the open space- problem solved.
One of the biggest challenge with this technique is that you will need to have a good budget- if you’re on budget you can try other methods below- you’ll need tools and hardware. But note that blocking the vents means your room won’t get any ventilations- so it’s important to consider that might arise before you go ahead and block your ventilation.
2. Cover your vents with soundproof blankets or curtains
This is one of the cheapest and also effective techniques to soundproof air vents. While this method won’t be effective as the technique above, it’s one of the cheapest soundproofing techniques. The curtains/blankets are easy to install and can be taken off when moving out.
If you’re living in a rented space, you can use this technique to avoid conflicts with your landlord. You can tack the blankets to walls or hangs them on curtain rods but either way ensure that you attach them as close to the ventilation as possible.
3. Use a Soundproofing sealant
One of the easiest and quicker methods is to use a soundproofing sealant which is available for cheap on amazon. I recommend Great Stuff Gap Filler will cost you around 10 bucks– I used it before and I was pleased with the results.
The foam sealant is sprayed on the vent and only takes a few minutes to get the job done. To apply the foam, you will need to remove the vent covers on either sides of the duct and fill the inside of the vent until no openings or gaps are present and replace the vent covers and you’re job is done buddy.
4. Create a sound maze in the vent
If you’ve got other bigger problems to solve, like have mold problem- sealing the vent is probably not the best idea. Therefore I would recommend creating a sound maze in your ventilation to keep airflow going.
The best way to achieve both sufficient airflow and noise reduction is to create a sound maze. A sound maze blocks sound waves making it impossible to reach your room but allowing air to flow.
Checklist for building a sound maze
Below is a checklist of all the tools I used to create a sound maze for my mom’s summer house in Texas.
- Thin plywood, just less than ½ inch thick
- A screwdriver to help you remove the vent covers
- wood glue
- A saw to cut the plywood into fitting sizes
- A utility knife
- Acoustic foam material
Steps in Creating a Sound Maze
- Use the saw to cut the plywood into pieces smaller than the inside of the air vents. Be careful not to cut them too big. Big pieces won’t fit on the vent and they will only end up blocking all the air. The more turns you create the more the benefit- so you can cut many pieces as you want to achieve this.
- The next step is to use the foam mats to cover the wood planks.- a glue is needed in this case.
- Use a screw driver to remove the vent cover.
- The fourth step is to use the wood planks (in second step) and attach them to the vent walls. Wood glue is needed in this case. Apply glue only on the side that’s touching the wall.
- Repeat this process with each single wooden plan. I would recommend leaving 1 inch space between one plank to the next- I did this in my mom’s summer house and found it good. But you can always adjust the measurement according to your preference. But remember a tighter maze is best for soundproofing purposes- so if you want minimal sound reaching your room- make a tighter maze. The opposite is true.
5. DIY Soundproofing Method
You can buy soundproof foam panels – my recommended is 8 Pack- Acoustic Panel Studio Foam Convoluted. Once the panels get delivered, cut them into sizes so they fit in the vent and place them in the duct. Make sure that the flat parts of the panels are stacked back to back creating a sort of spiky foam boxes.
6. Home Renovation
If I had tons of money at my disposal I would have knocked down the portions of my mom’s house and get a permanent solution to noise problem. Do you have some cash at your disposal? Can you invest the money in doing home renovation?
Are you willing to get your hands dirty?
If your answer is YES- then completely removing the above the vents from your home will give you a permanent solution to your noise problems. You can achieve this by doing a home renovation and replacing the vents with drywall.
However, the problem with this method is that it’s time consuming and expensive. You will need to spend your cash on drywall, tools and many other accessories and some bit of labor.
Soundproofing HVAC vents
HVAC vents are complex systems not easy to deal with. But there are a few techniques that you can use to significantly reduce the external sounds entering the room.
1. Upgrade the HVAC system
Some old HVAC systems are so loud such that your neighbors might think you’re launching an alien space ship in your house when turned on. If you got such in your home, I would recommend upgrading to newer ones which are quieter and energy efficient as well.
2. Duct Liners
Lining the duct is one of the cost-effective way to insulate the sound. Duct liners are made with an insulation material which significantly reduces the sound reflecting from the inner walls of the HVAC ducts.
The insulating material is fitted inside the walls of the duct. One of the best duct liners I would recommend to anyone wishing to get one for his HVAC system is Reflectix which is not only cheap but also effective- it’ll only cost you less than 30 dollars.
3. Create a sound baffle
My good friend from Texas, just a few miles from my mom’s place introduced me his sound baffles. Typically a sound baffle is a box that forces sound to travel along a bent on an elongated path. It’s like a maze fitted with sound isolating materials on the inner walls.
There you have it ladies and gentlemen, six different techniques to soundproofing air vents for a quieter and peaceful environment. What method do you think you’ll try now you have the information at your fingertips? Please let me know in the comment section below and keep the discussion going. I will be glad to help.
Looking for more DIY soundproofing projects? Use these simple DIY tricks to soundproof your washing machine and your bathroom of course.