Let me guess. You’re about to have a peaceful sleep until you hear UNBEARABLE noise from the return air of your AC.
Since you cannot tolerate it, you look for solutions to reduce noise from return air.
But none of the solutions you found SEEM TO WORK for the return air.
Well, don’t worry. We’ll show you 9 methods on how to reduce noise from return air.
9 Ways How to Reduce Noise From Return Air
1. Open Your Air Vents
Before fixing anything else for the return air, you might want to check your air vents.
One closed air vent would not cause any problem. But, having more than one closed vents spells trouble.
Inspect your air vent or grills to see if you can adjust them. If so, orient your grills and vents in such a way that you can achieve maximum airflow.
That’s why it’s essential that you’re checking the air vent and opening it once in a while. Closed vents = MORE trouble!
2. When Was the Last Time You Cleaned Your Return Ducts?
If the first step on how to reduce noise from return air is not enough, this will help you reduce noise by A LOT.
Inside your AC, the air ducts and filters cover the return air. In this setup, the filters are prone to clogging by dust and other dirt.
Expect a clogged filter in a dusty bedroom. With that, you must consider regular cleaning of BOTH the air filter and grill.
Don’t worry; cleaning and changing the filters is a piece of cake. You can do it yourself without asking for professional help.
You can either vacuum or deep clean the grill. Take some time to clean the duct opening as well.
3. INSPECT the Ductwork
How to reduce noise from return air if the problem is the poor installation of your AC in the first place?
In that case, you might need to CONSULT AN AIR CONDITIONING PROFESSIONAL to guide you in dealing with your issue. It’s better to have the expert resolve ductwork issues than take a risk in manipulating the ductwork.
Upon asking a professional, you can opt to install a fiberglass duct liner instead. This flexible duct MINIMIZES the sound created as flows of air return.
4. Get the Right Air Vents and Grills
Check the vents and grills of your AC for cleaning and adjustments. Ensure they have the PROPER DIMENSIONS.
You must look after these features to see if the air vents have an ample opening for smooth airflow.
If that’s not the case, seek help from a professional for a correct replacement.
5. Too Much Static Pressure? REDUCE IT.
You might find your AC having too much static pressure. While it’s normal for some units, you must seek a solution if it becomes a problem.
High static pressure forces your AC to handle high air volume due to PRESSURE BUILDUP.
If you ask a professional, expect to hear a solution from any of the following steps:
- Adjust the fan speed to a comfortable level that your AC can handle;
- Increase the ductwork by expanding both the supply and return plenum;
- Get a bypass duct for a single multiple-zone system;
- Expand the return air capacity by adding registers and increasing grill size; or
- Switch to high-velocity grills and registers.
6. Consider a Variable Speed Blower
You might already consider replacing your AC once you’ve checked its components. If you’re in that process, why not get a variable speed blower?
A variable-speed blower allows for more consistent air circulation in your house. At the same time, less air moving through the air ducts.
What’s great is that these variable speed blowers tend to operate with less noise!
7. Work Out the Central Return Problem
When you’re in a small house or building, it’s hard to process how to reduce noise from return air. Chances are you will find the air handler or furnace sitting next to the return plenum.
If that’s the case, your cooling system is NOT the problem. The space and design of your home are the real culprits.
So if your cooling system’s blower motor is close to your space or you have an air handler installed behind your bedroom wall, you might want to rearrange your home.
Don’t hesitate to ask experts in dealing with limited space.
8. Make Your Return Vents Soundproof
The last thing you can think of how to reduce noise from return air is to make the vents soundproof.
In doing so, you must be mindful that any material you use can impede airflow that can also affect the air volume and pressure. You can ask an expert on which material and equipment suits your return air vents.
You can do the following steps to reduce noise in your return air vents to comfortable levels.
- Cover wall vents with a soundproof material like sound-dampening curtains. These curtains are thicker than a typical curtain because of their sound-dampening function.
- An expert can also plug your vents with acoustic foam.
- The other thing you can do is to build a sound maze inside the vents.
Each step requires different equipment. Each one can do something to reduce noisy air return in your vents.
9. If All Else Fails: Consult an HVAC Professional
From ductwork issues to cleaning your filters, sometimes you need an expert’s opinion to ELIMINATE the problem.
You might think the consultation and labor fee is costly. But actually, too many trial-and-error “fixes” might only lead to MORE HARM than good.
What’s With the Noise From the Return Air?
In reality, you could expect to hear some air noise from your HVAC system.
As much as you want a silent operation of your AC, you should be more worried when your AC produces no sound at all.
Noise is a sign your HVAC system is up and running. Yet, excess or annoying sound from return air calls for some immediate attention.
So, how do you know what kind and how much sound is problematic?
Look for These Signs:
You might notice the sound becomes louder, or it comes with unusual sound such as rattling or a flapping sound. If you observed these signs from your HVAC system, you need some repairs.
Aside from a lot of noises, you can tell that your AC is working harder than usual. This behavior is a sign of INADEQUATE AIRFLOW, prompting your system to consume more energy.
Once you notice these signs, you might need to inspect your AC for the potential cause:
- Dirty filters
- Closed or blocked registers
- Sealed duct dampers, or
- Debris trapped in the ductwork
If left unattended, your air conditioning system becomes more vulnerable to malfunctions and breakdowns.
Resolving the problem requires you to deal with the root cause. You must do this BEFORE your AC incurs severe damage over time, worse than noise only.
Another possible cause of the noise is the leaks in the return vents and air ducts/filters. Leaky ductwork tends to pull air from the outside into the air ducts instead of leaking it.
This event adds to the volume within the ductwork, altering the static pressure as well. Over time, this issue builds a positive static pressure.
Under such static pressure, return air tries to escape through the cracks and gaps formed in your return vents. This pressure problem, in particular, needs a solution before it damages your ductwork.
What’s Inside Your Air Conditioning System or HVAC System
Consider a circulatory system analogy — you could treat your HVAC or AC as the heart.
The circulating air in your AC and air vents acts like blood flowing within your body.
And which part of the AC system acts like vessels? The air ducts scattered around your home or building.
Like your blood vessels, there are two kinds of air ducts in the system:
- Supply ducts
- Return air ducts
And, you guessed it right. These air ducts correspond to the type of air they deliver within the system.
The Supply Air Ducts and Air Vents
To better understand, you can follow the journey of the circulating air within your building or home’s air ducts and supply vents.
The adventure begins upon the release of the supply air from its source. The supply air can either come as heated air from the furnace or cooled air from the AC.
From this point, the supply air duct delivers the supply air into its expected destinations in your house or building. The supply air gets into every room through the supply vents, air vents, and air ducts.
The Return Ducts and Return Vents
Once the air passes a room, the return air ducts draw it out via separate air vents. A unique feature of the return air duct is the presence of air filtration systems.
Along its way, the circulating air encounters ALL SORTS of contaminants and pollutants. The return vent has a filter on board to prevent materials like dirt and dust from accumulating in your HVAC system.
After some time, the return air goes back in circulation before reaching the central unit of your HVAC or AC.
At this point, the air gets heated or cooled again before it circulates again.
The Repetitive Cycle of Air Circulation in HVAC System
The air distribution system in your house or building is a closed-loop system. It means that the SAME AMOUNT OF AIRFLOW circulates within the system over and over again.
Sounds cool, right? But that also means your HVAC system basically recycles and sends back the same airflow you breathed in 5 mins ago!
After going through these guidelines, you’ll be one step closer to a more quiet home .
Whatever the case you have with your A/C at home, we hope this article helped you reduce noise from return air and make your A/C system quieter.
Think of this article as a first aid to your noisy return air. If all things fail, don’t hesitate to ask for help from a professional.
July 12, 2021 – updated external links, removed, affiliate links, added video embeds
June 28, 2021 – added changelog, added 1 external link, fixed and updated article format and content, updated internal links, optimized content