Evaporative coolers offer a convenient alternative to HVAC systems. But they can be noisy. If you’ve experienced this issue, here are 6 evaporative cooler noise reduction tips:
- Stand it on a mat
- Place a barrier in front of the unit
- Build a quiet box
- Run the cooler on a lower setting
- Keep the cooler away from walls
- Buy a higher end unit
I’ll go over these in more detail below, but first I’ll look at why evaporative coolers make noise.
Why do Evaporative Coolers Make Noise?
Evaporative coolers are more economical to run in dry climates than traditional air conditioning systems.
Rather than using refrigeration, they rely on the principle that water absorbs quite a lot of heat in order for it to evaporate.
In short, the hot air is passed through the system and its heat is transferred into liquid water, which then evaporates. The result is cool air flowing out of the system.
While this process uses less energy than air conditioning, it’s still fairly loud.
If nothing else, the machine’s motor creates noise when it runs. Sound is a common waste product of any mechanical device, so this is completely normal.
On top of this, it has a pump, which can be a big source of noise. Then you have the cooler’s multiple fans and the sound of water trickling through the unit.
That said, evaporative coolers are designed to be a quieter option than air conditioning units, so you’re already in a better place by choosing one of these.
Before you start soundproofing your unit, it’s worth checking it over to ensure its noises aren’t signs of a mechanical issue.
It should make a whirring noise as standard, along with the trickling sound of water.
But if it’s hammering, clunking, or grinding then you might have a bigger problem on your hands.
Like all mechanical devices, evaporative coolers need regular maintenance to work properly. You should check it over during the fall if you plan on putting it away over winter, and again in spring before using it.
If your unit is hammering then you likely need to adjust the water float supply line. This is fairly simple: open up the machine and locate the float. Then just raise it slightly.
Clunking or grinding
Both of these noises imply there might be an issue with the fan or the rotary motor. Aside from replacing the fan, there’s little you can do yourself. It might be best to take it to a specialist so they can check it over.
Providing your evaporative cooler is making what you consider to be “normal” functioning noises, you can move on to soundproofing it.
Tips for Reducing Evaporative Cooler Noise
When it comes to reducing evaporative cooler noise, you do have to bear a few things in mind.
First is that you can’t restrict the airflow. Doing so would reduce how well the unit cools and could cause it to break.
Second, you have to be careful insulating it. The unit needs to dissipate heat to work properly, and impacting this could cause it to stop working. Finding the right balance will be key when soundproofing it.
1. Stand it on a mat
One of the biggest sources of noise with evaporative coolers is transmission into a surface.
Any noise the unit makes can be amplified by the surface on which it sits.
For example, a cooler will make much less noise if it’s sat on compacted earth than it would on a metal plate.
Luckily, this is a really simple problem to solve by placing it on a mat that’ll dampen any vibrations.
There are a couple of products you can use for this job:
- EVA foam gym mats (Amazon link)
- Sound deadening mat
Either of these would be ideal because they’re soft but dense, and so will dampen vibrations and prevent them from transmitting into the floor.
Be careful if you choose sound deadening mats though. They’re designed to provide thermal insulation and so have a foil cover. This could reflect heat back at the unit.
That said, minimal heat will escape out the bottom so it shouldn’t be too much of a problem.
If this is a concern, just put a blanket over the mat to remove the reflective surface, or use it upside down.
2. Place a barrier in front of the unit
A simple option for reducing noise levels from your evaporative cooler is to put a barrier between you and it.
The purpose of the barrier is to reflect sound waves back at the source, meaning they shouldn’t be able to reach you.
A piece of plywood or MDF with a layer of mass loaded vinyl should do the job fine.
Mass loaded vinyl is limp mass, meaning it dissipates sound waves rather than allowing them to transmit into the structure.
If noise is a big issue with your unit, consider putting a barrier on each side.
Your barrier should be at least as tall as the unit; ideally slightly taller. Sound waves are directional, meaning your barrier needs to be higher than the noise source.
When fitting the barrier, ensure you leave enough room around the unit to allow proper airflow. Around 3ft between the barrier and unit should be fine.
3. Build a quiet box
A quiet box is exactly what it sounds like: a box you fit around a noisy object to reduce the sound you can hear.
You’d typically make them for things like a generator or sump pump, but it should do a good job for an evaporative cooler.
You’ll need the following materials:
- Mass loaded vinyl
- Acoustic foam
- Green Glue (Amazon link)
- Nails or screws
Here’s the method:
- Measure the cooler and add a couple of inches to each measurement.
- Cut out pieces of MDF for each side and the top. You should have 5 pieces in total.
- On what’ll be the inside of the box, glue down a layer of mass loaded vinyl to each piece.
- Once this is dry, stick down a layer of acoustic foam.
- Cut holes in the front and back for proper airflow.
- Assemble the pieces using nails or screws. Seal any gas with Green Glue.
- Cut a hole in the back for the power cable and place it over the unit.
Be aware that the holes will need to be big enough for it to operate properly. If your cooler has a fan on the front, the hole should be at least the same size.
If your unit has some kind of exhaust tube then it’ll be much easier for you to direct the air outlet. Simply cut a hole for this and feed it through.
Obviously the bigger the holes, the less noise will be blocked. But it’s important to find the right balance between noise reduction and proper function. This’ll depend on the size and design of your cooler.
4. Run the cooler on a lower setting
It might sound obvious, but the more work the motor does, the louder it’ll be.
If you’re concerned about insulating the unit too much then the next best option is to just run it on a lower setting.
The cooler’s fan-only setting will be the quietest because it won’t be operating the pump or cooling system.
Also, if it has an oscillating feature (where it swivels in different directions), turning this off will reduce noise levels even more.
This isn’t the best option for reducing overall noise levels but does save you from having to buy any new products.
5. Keep the cooler away from walls
Walls are great surfaces for reflecting sound waves. The harder and smoother a wall, the more effective it is at reflecting.
The same is true for corners. A 90-degree angle creates multiple reflection points for a sound wave, which can lead to echo or reverberation.
Getting around this is simple: don’t place your evaporative cooler near a wall or corner.
I’d recommend keeping it at least 3ft away from walls, but the further into the middle of the room it sits, the better.
If this isn’t possible, fixing some sound absorbing materials to the wall should reduce the issue. Acoustic foam will do this job well.
6. Buy a higher end unit
As with almost any mechanical device, cheaper models will usually make more noise. Whether it’s poorer connections or cheaper parts, they’re simply not designed as well.
A general rule is that higher end models are designed better using better parts. A more expensive evaporative cooler (Amazon link) should run quieter and more efficiently than a cheaper one.
Of course, not everyone has the money to spend on an expensive unit. But if it’s something you use a lot, and you’re not content with the noise reduction levels of your current unit, this might be the best option.
Some Final Thoughts
I hope this article has given you some useful tips for reducing evaporative cooler noise.
Remember you need to balance insulation against airflow and heat dissipation otherwise the cooler might stop working.
Providing you do this, it shouldn’t be too hard to drastically reduce its noise levels.