It is a warm summer evening and you are grateful for the cool air your air conditioner provides. But chilled processed air is not the only thing your AC is producing. There’s also this persistent humming, buzzing, or whirring sound.
Are these sounds normal for a functional AC unit? What are the common causes of a noisy air conditioner? This article will at the very least help you turn it down but also show you how to block air conditioner noise.
Why is Your Air Conditioner Noisy?
Air conditioners are one of the few rather big machines we utilize in our homes almost daily. Like with all sizeable mechanisms applying mechanical power and with plenty of moving parts, HVAC units are expected to induce some sounds.
However, you should also watch out for strange noises from your AC unit that may signal some mechanical problem.
Here are the common reasons why your air conditioner is making those loud noises and whether you should be alarmed or not.
Wobbly Components
Central air conditioning systems are particularly massive and they have an outdoor unit for exhausting the heat drawn from the indoor air of your home. These components have numerous moving and stationary parts inside them.
The elements of the outside unit that are in motion are already producing some type of sound as they operate. The cooling fan has that whirring sound, while the compressor naturally creates noise as the pistons compress the refrigerant as part of the cooling process.
But you should be wary when you hear some clanking or banging noises as those are not normal mechanical sounds. A likely cause is some parts that should be stable and fixed became unhinged at some point. Check for loose screws, bolts, and nuts hitting the metal sides of the box or other metal parts.
Broken or Worn Out Compressor
The compressor is a highly essential part of the air cooling system. Without it, the cooling process will not even take place and your precious AC will be rendered useless.
Its job starts by compressing or squeezing the refrigerant while it is in its low-pressure gas state. As the compressor keeps on pressing, the low-pressure gas increase in temperature and becomes a high-pressure gas.
Next, the compressor pushes the hot high-pressure gas through the condenser coil where some heat from the gas will be removed, turning the gas into a liquid. When the warm indoor air extracted from your home comes in contact with the liquid refrigerant, the refrigerant evaporates taking with it the heat from the indoor air. What comes out of the AC is slightly cooler air.
This cycle initiated by the compressor will go on and on until your desired temperature is reached. The entire cooling cycle should be relatively quiet and seamless.
But if the compressor has been worn out due to the age of the unit, accumulated dirt, and lack of adequate maintenance by an HVAC professional, it will churn out an undesirable grinding noise.
To prevent this particular AC noise early, subject your AC unit to regular and proper annual checkups and services by a certified expert. Regardless of how many years your air conditioner has already seen, constant upkeep by a quality contractor will significantly reduce the air conditioner racket your compressor may make.
Dirty Outdoor Air Conditioner
We are not talking about your dirty air conditioner’s filters making a racket. (Although if your filters are indeed dusty and grimy, you may want to clean them immediately as it would cause different sets of problems). We are pointing to the various debris and foliage that may fall inside the outdoor air conditioner that can induce infuriating noise.
If you own a central or split-type air conditioner, you obviously have an alfresco component in your garden or backyard. This part of the AC unit is exposed to external elements such as rain, strong winds, snow, trees, and animals.
If sizeable debris falls into the air conditioner’s interior, it could cause a lot of rattling sounds as the leaves, sticks, or pieces of ice tumble inside the compartment. Should you hear this particular noise, take a peek inside the condenser unit and free it from any dirt or obstruction.
Aging Unit
This may be difficult to hear but your air conditioner is not supposed to last forever despite how much we wish it. Deterioration of its mechanical elements and maybe corrosion on some of its metal parts produce unappealing sounds.
Additionally, relatively old models of cooling units are more concerned with the efficiency of lowering the temperature and not so much with dampening the sounds they make. In comparison to newer, state-of-the-art versions, innovative AC manufacturers want to separate themselves from their competition by adding whisper-like quality to their products.
If you are concerned that you have to say goodbye early to your trusty ol’ air conditioner because it might get noisy in time, let us soothe your mind.
Regularly and properly maintained units could last up to 20 years with very minimal issues. It is all about high-quality installation by a trained professional, correct sizing, and routine annual maintenance. Read about it in full in our previous article on the subject matter.
Since you are not so crazy about replacing your perfectly functioning AC just because of the sound it makes, let us discuss some ways to quiet down air conditioner unit noises.
How to Block Air Conditioner Noise
Air conditioners are crucial for healthy and agreeable living, especially in warm and humid climates. But so is a noiseless and relaxing environment. And stuffing your fingers up your ear is a poor solution. So here are some practical air conditioner tips for blocking its annoying sounds.
Install a Sound Blanket
A reliable and common way to block the noise air conditioner makes is to install a sound blanket. Also known as the acoustic blanket or sound curtain, a sound blanket is usually made of fiberglass covered with vinyl.
But this sound curtain will not go to your windows but in the air conditioner’s interior. Your trusted technician will install it around the compressor. As its name suggests, a sound blanket will cover, obscure, and absorb the air conditioner compressor sound such as loud vibrations and noise.
Besides putting the soundproofing blanket inside the AC unit itself, you can also install it on a wall nearest to it and the fence close to your neighbor’s wall. This step can reduce up to 40% of the compressor noise. It is best to pick a soundproofing product that can be painted over and can last for many years against the elements.
Does the air conditioner sound blanket really work? If done correctly and with the appropriate material, a sound blanket could reduce the noise by 30% to 50%. It should not impede the airflow but in fact, prevent condensation to form on the compressor, and enhance the unit’s efficiency by insulating it.
Build a Noise Barrier or a Quiet Fence
Another soundproofing option is the noise or acoustic barrier. It is an external structure that homeowners build to protect themselves and their neighbors from noise pollution. This is especially helpful when you want to block the noise from your HVAC while your visitors enjoy refreshments on your patio or garden.
Some people hire a professional builder with expertise in acoustics-related structures. The noise barrier may be made out of wood or vinyl.
Erect the solid barrier or fence between the wall of your house and the noisy AC unit. Some manufacturers of ready-made noise screens suggest an L-shape or U-Shape installation in front or around the unit.
Make sure that the partition has no gaps or leaks that the sound can still pass through to effectively reduce air conditioner sounds. The wall should have a density of at least 20 kg per square meter to be functional.
Some quiet fences may also be reused to soundproof pool pumps, pool heaters, and other out-of-doors machines.
Pick the Right Location for Your AC
Does the placement of your air conditioner also affect the noise it produces? Absolutely! If you have an air conditioner placed outside of your house but did not think through where to put it, you may unknowingly generate a lot of noise for yourself and your neighbor.
What you need to remember is that sound is a wave. As the sound bounces off of some hard reflective surfaces, its intensity increases. So if the houses are fairly close to each other and the air conditioner is sandwiched between two walls, or if the unit is near an internal corner, noise is inevitable.
Keep your AC away from bedroom windows, living areas, and even further away from your neighbors’ walls. Avoid installing the unit between any reflective surfaces to minimize the chance that sound waves will bounce and get amplified.
Soundproofing the Home Not the AC Unit
You may think, “Well, I’m just going to close in this whole thing!” But that is not what air conditioner soundproofing is about. That may be too simple a solution because it would mute the sound significantly. But there are good reasons not to confine the unit so much.
The hot air generated by the AC will be trapped and recycled back to the cooling fans and into your home. Your AC will straightaway lose 25% of its efficiency and will easily overheat. An AC unit that is so restricted will also consume greater electricity. Nobody wants that kind of additional expense! Ideally, there should be a minimum of 18 inches of clearance around the air conditioning unit to allow the air to flow naturally.