Before we dive deeper into sound blankets and how to use them with your air conditioner, let’s go over the different types of sound you’ll be dealing with in your AC unit.

Structural Noise in an Air Conditioner

Structural noise occurs when one object makes contact with another, passing vibrational energy through the structure, which is heard as noise. For example, if your air conditioner is installed directly against your house so that the unit is touching your walls or if the unit is on a concrete slab, structural noise is part of the problem. If it is structural nose you are dealing with, you should be able to distinguish that from the other noise, and even feel the vibrational energy being transmitted with your hand. Unfortunately, sound blankets aren’t designed to help with structural noise. Instead, you should decouple your air conditioner unit from the wall.

For structural noise, your best options are to isolate the two hard surfaces from each other. We use rubber isolation pads or a heavy duty rubber mat to accomplish this goal. If you can decouple the two hard surfaces from each other, you’ll stop the structural noise.

Airborne Noise from an AC Unit

Airborne noise is any sound that travels through the air. This type of sound can transfer through the smallest gaps and cracks in a wall and can easily be heard through thin barriers. Examples of airborne noise with an air conditioner include the compressor or the fan whirring. The best way to deal with airborne noise is to add density and absorption to a structure, so sound blankets are an effective combo treatment for air conditioners needing airborne noise reduction.

Step One: Build a fence or enclosure

For a residential air conditioner, you may not already have fencing in place. It’s most common to build a wood fence, but any kind of support structure will do. Just ensure that the fence is placed near the AC unit and is at least 50% taller than the air conditioner (we’d love to see 2x the height!). You don’t have to enclosure the unit on all side, but just recognize that the sound will be escaping out whichever side you don’t enclose. Make sure you’re ok with the sound going that direction.

Step Two: Ensure the Air Conditioner Gets Proper Ventilation

We talk a lot about creating “airtight” soundproofing application to prevent sound leaks. You do NOT want this when treating an air conditioner. ACs need airflow to function properly, so if you seal off the enclosure completely, you’ll damage the unit. To get the benefits of a roof without actually having a roof, we recommend adding a slanted roof to the top of the enclosure ith an opening that points away from wherever you don’t want the noise. Once you line the inside of the enclosure, any sound that does escape will head in the direction you face that opening.

Step Three: Use Air Conditioner Sound Blankets on the Interior of the Enclosure

Once you have built your soundproof fence or enclosure, you can line the inside of the box with Our Quiet Quilt Outdoor Soundproof Blankets or Quiet Quilt Outdoor Acoustic Blankets. If you built a dense wall or fence out of wood – you’ve already got a pretty good barrier and can use the acoustic blankets. If you have a chain link fence or your barrier has openings/gaps, you will need the added density of the soundproof blankets. Make sure to cover the entire interior of the enclosure so that as the sound bounces around inside your enclosure, it’s hitting as many absorptive surfaces as possible. Again, make sure you get our outdoor rated blankets, so they’ll last 15+ years in the elements.

If you have more questions about soundproofing an AC unit or any other soundproofing queries, feel free to reach out to us. These blankets are also great sound blankets for window soundproofing, if you want to stop the noise from entering your home. A soundproofing expert at Second Skin is always ready to help!

Sound blankets are an easy and versatile way to reduce airborne noise. Unlike a “normal” blanket, our Quiet Quilt Soundproof Blankets include a sheet of mass loaded vinyl as a backer behind the absorptive face. Mass loaded vinyl is an excellent soundproofing material because it is VERY heavy and effective at stopping sound from transferring.

Our Quiet Quilt Outdoor Soundproof Blanket is incredibly dense, weighing 1.5 pounds per square foot. The grommets on the blanket make it straightforward to install and remove when needed. The product is also UV rated, waterproof, and wind load tested, so it is designed specifically for outside use.

The Quiet Quilt Soundproof Blanket has an STC rating 33 with a 2” thick absorber on the front. When we install it as an enclosure around a piece of machinery, we see a noise reduction of at least 10 decibels and can often get to 15+ with a four sided enclosure. Please keep in mind that we are talking about building an enclosure AROUND an air conditioner, not covering the sides of the unit. We do not recommend hanging blankets (or anything else!) directly on the air conditioner.

The best way to soundproof an air conditioning unit is to utilize existing fencing around the unit or to build fencing around it before lining the enclosure with sound blankets.

Soundproofing a Commercial Air Conditioner with Sound Blankets

For commercial air conditioning units, there’s typically safety fencing already around the unit. The install in this situation is extremely simple because we’ve already got a chain link fence. We’re going to utilize the existing fencing and hang the Quiet Quilt Soundproof Blankets using the pre-installed grommets and zip ties or wire ties. The results are awesome, and the sound will be greatly reduced.