Shop vacs are loud. Those that are generally bought and used in homes or garages produce between 70 decibels and 80 decibels of noise. Commercial shop vacs will regularly make over 85 decibels of noise. 70 decibels is the sound of your shower, 80 decibels is the sound of an alarm clock, and 85 decibels sounds like a passing diesel truck.
Shop vacs are loud because they consist of a large hollow canister and a very powerful motor with a large fan. They are designed to pick up fairly heavy and/or wet messes. Here are a few ways to make your shop vac quieter.
Note: Permanent hearing loss or damage can occur after 2 hours of sustained 85 decibel sound.
6Ways to Make Your Shop Vac Quieter
You are never going to be able to completely silence a shop vac. Just too much power, too little mass, and too big a fan. But with a little bit of effort, you may be able to make the noise more acceptable.
1) Keep it Clean
As is generally true with most equipment, clean shop vacs run more efficiently, last longer, and make less noise. Even though they are a fairly simple machine, there are still parts of a shop vac that can get dirty, become clogged, or restrict airflow. Restrictions usually occur in the hose, wand, or attachments.
Clogs are pretty easy to detect. Vac performance can suddenly become marginal when debris stops better than 50% of the air flow. These types of clogs happen when something gets wedged in the hose or accessory, and more garbage piles up against it.
Air restrictions are a little more stealthy because they can build up over time. One scenario could be: a little water is sucked into the pipe, then some drywall dust which adheres to the moisture. The dust hardens. A little more water. A little more dust. Eventually, you will notice that the vac is not picking up everything.
Once you have run something heavy through hoses and wands to dislodge any clogs, use a water hose to spray water through all of the attachments to get them clean. Make sure they are dry before using them again. If you have access to a pressure washer, mix a little soap into it and clean everything. Taking your vac accessories to a car wash also works very well.
2) Get a Longer Hose
Adding extra hose length will not make your shop vac quieter. But it will move you farther away from the noise. Much of the noise you hear from your vac is caused by the fan sucking air and debris into the machine, and blowing air out of the machine. You are always going to be fairly close to the intake but moving an extra10 feet from the exhaust will be helpful–especially if it is pointing away from you.
Beware of the law of diminishing returns. The longer the hose, the less suction. At some point it will become inefficient and will not be able to pick up debris.
3) Keep the Air Filter Clean
Shop vacs come with a number of different types of filters. Some have a replaceable filter like your car’s air filter. Some are cleanable and reusable. Some–like my small shop vac–are a filter cloth that can be washed and reused. (Your owners manual will explain what type you have and what kind of maintenance is required.
As with a clogged wand or hose, a dirty filter will affect performance. You will notice less suction and more noise. A clogged filter will also make the vac work harder and make more noise. If you neglect cleaning or replacing the filter long enough, the motor can overheat and will eventually be damaged. By working harder, it could actually suck dust through the filter and into the motor–causing more damage.
If you have a cleanable filter of any kind, make sure you follow the manufacturer’s recommendations and schedule. If your filter cannot be cleaned, keep a replacement on hand at all times. Never use a shop vac without a filter. The chances of causing damage to the motor will approach 100% very quickly.
4) Build a Soundproof Enclosure
At first this may seem like a strange idea. And for many situations, it is untenable. For instance, a window installer carting tools and a vacuum from room to room and up and down stairs does not need to burden himself with a clumsy box that houses a vac.
But people who do most of their woodworking and DIY projects in a shop environment may consider a sound-reducing enclosure a great idea. Many people also use vacuums as sawdust extractors by hooking them up to table saws, miter saws, planers, etc. This is akin to the extractors used in commercial operations.
Adding wheels to your vac enclosure allows you to move it around the shop as required. Even out onto the driveway if needed.
How to Build a Noise Reducing Box
Designing and building a noise reducing box for your shop vac has a few different requirements than boxes for compressors or generators. The most important thing is that you have to remove a vac regularly to empty it. Meaning that you cannot make it solid in the box. Or extend hose, switch, or power connections to the outside of the box for easy use. (Compressors and generators may only have to be removed from a box once a year for oil changes.)
- One 4 x 8 sheet Good 1 Side 3/4″ plywood. Plywood has lots of mass for soundproofing. You can use MDF for even more mass, but it is heavy and sawdust and glue does not hold screws as well.
- 30 square feet Mass Loaded Vinyl (1 lb. per square foot). MLV can reduce noise by up to 23 decibels. Other options include 5/8″ polyester acoustic panels, or another layer of plywood with Green Glue sandwiched between them.
- 2 foot piano hinge and latch
- Four 4″ locking castors
- One or two handles
- Miscellaneous: 2″ deck screws, stapler with 1/4″ staples, glue, self-adhesive compression weatherstrip
- Nice to have: 1″ outside wooden corner bead, paint
I am going to assume that the owner of a shop vac will also own the necessary tools to build this box, along with the knowledge. So I will just mention a few things. After you have all of your pieces cut, install the Mass Loaded Vinyl (MLV) on all inside surfaces flush with the edges. You can glue it (contact cement), and staple the edges, or just pull it tight and staple the edges only. Trim off any excess.
The idea of running MLV edge to edge is to eliminate the need to caulk the seams. When the pieces are screwed tightly together, the compressed MLV should seal the joints. Cut 2 half-round notches in the top where it meets the door. One big enough for the hose and one about an inch in diameter to accommodate the power cord. These openings are bigger than necessary on purpose to allow air into and out of the box. Install the door with the piano hinge, latch and weatherstrip.
If you plan on moving the vac around in the box, attach wheels and handles. For more information on how to build a soundproof box, please see our article 17 Ideas on How to Build a Soundproof Box for Air Compressor. These plans are for an air compressor box but most of them can easily be modified to suit your shop vac. And they all have much more detail.
Note: You may want to build the box big enough to store all of your accessories.
5) Use Hearing Protection
Using hearing protection will not make your shop vac quieter. What it will do is make your working environment quieter and safer. Although there are many types of ear protection available, the two most commonly used are foam ear plugs and commercial-type over-the-head earmuffs.
You can get more information on different types of earmuffs from our article The Best Noise Cancelling Earmuffs for Sleeping. (Although the article is aimed at earmuffs for sleeping, there are some ideas you might find attractive for your situation.)
Note: Everyone should be wearing ear protection when noise levels start getting close to 80 decibels. Two hours at 85 decibels can cause permanent hearing damage. And I am willing to bet that not all ears are created equally. Some hearing will probably be damaged at lower sound levels.
Single-use foam ear plugs are very inexpensive–starting at under $10.00 for 50 pairs. The better ones will reduce the noise entering your ears by over 32 decibels. This significant decrease can bring the noise level down to around 50 decibels- the sound of your refrigerator. Roll them into a small compressed tube before inserting them into your ear canals. They will expand to fill the available space and block noise.
Some people find earplugs too annoying to wear. Or they find themselves allergic to the foam. Move on to other options.
Over the Head Earmuffs
Over-the-head earmuffs are reusable. You can get many years of use out of a good pair. You can buy them for as little as $15.00, with the better products costing over $50.00. There are multiple types of cushions and padding. They are available with speakers for music, Bluetooth, or with radios in the muff.
The less expensive options will reduce noise by around 24 decibels–making your shop vac about as loud as normal conversation. More expensive earmuffs will reduce the noise level by well over 30 decibels–bringing the noise level down to the sound of your refrigerator.
6) Buy a New Quieter Shop Vac
Before buying a new shop vac because of the noise your old one makes, try the other noise-reducing suggestions on our list. If you are planning to get a new shop vac–for whatever reason–make sure you buy a quiet one.
There are quite a few makes of shop vacs that produce less than 70 decibels of noise. And you can still incorporate some of these ideas to make it even quieter. Makita makes one rated at 59 decibels–the sound of normal conversation–on a low setting.
Many new vacuums have more than one-speed setting, can handle either wet or dry material, and come with quick change filters, and extra long hoses.
Buy a smaller Shop Vac
Smaller shop vacs are usually a little quieter. They are also easier to move around. If you find the right one, there is very little difference in versatility. The little Stinger in the picture is a wet/dry vac that requires no filter change. It has cleaned the interiors of dozens and dozens of window replacement jobsites. More than enough power for screws, nails, drywall, and melted snow.
A Few Other Ways to Make Your Shop Vac Quieter
- Open Spaces. If at all possible, use your vac in an open space. For instance, take your car out onto the driveway to vacuum it out. And use a hose long enough to keep the vac a ways away. Open the doors and windows of your garage to eliminate some of the echo. Shop vacs tend to operate at fairly high frequencies, which makes the echoing even worse.
- Muffle the Exhaust Outlet. Many shop vacs come with a muffler/diffuser. If yours does not have one, you might be able to buy one from the manufacturer or find an after-market muffler that will fit. If all else fails, some different sizes of ABS pipe and ABS glue combined with a little creativity should let you make one that works.
- Broken Parts. Shop vacs are pretty tough but they are not unbreakable.. If you are losing suction and/or have a whistling noise coming from the machine, check for cracked hoses or accessories, a poor seal between container and lid, or even a cracked container. Depending on where, and how bad the damage is, it might be reparable or you might need replacements.
- Motor Problems. Although rare, you might experience worn bearings or damage to the fan. Both of these problems are repairable, but I would not bother. You have probably used your shop vac for years and gotten your money’s worth out of it. You can find a good vac for $100.00 or less. Quieter, more powerful, and with a warranty.
- Power Setting. Most shop vacs have at least 2 power (speed) settings. Less power and slower speeds mean less noise. Use lower settings if you can, to keep your shop quieter.