A quick search produces many choices for wet/dry vacs from many manufacturers, so how do you choose the one best for your shop? BestReviews is here to make sure you’re informed before making your purchase. We’ve researched the top wet/dry vacuum brands, surveyed owners, and consulted our expert, Allen Rathey, to help you make the best decision. And because we purchase the products we test, you can always count on our reviews to be unbiased.

Just like a vacuum cleaner for rugs, wet/dry vacuums have a powerful motor and fan that creates suction by drawing air into the vacuum’s canister, through an intake port, and upward through an exhaust port.

Unlike a home vacuum, a wet/dry vac typically employs a two-chamber system to separate solids and liquids. Debris is sucked in through the intake port of the outer chamber, using a hose that attaches to the intake, and helps direct and speed up airflow. Once inside the chamber, the airflow decreases. The debris and water exit the airstream and fall down into the inner chamber. Meantime, the air continues its upward journey, passing through a filter to strain out any fine dust and debris before exiting via the exhaust port incorporated in the motor housing.

Switching the vacuum from dry to wet vacuuming is almost as easy as flipping a switch ⸺ with one caveat. You must change the filter from a dry filter to a wet filter before tackling that puddle of water. Dry filters are made of paper, which doesn’t make them a great option for filtering water. Wet filters are usually made of foam and soak up the liquid.

Wet/dry vacuums come in a range of sizes:

• Mini: This vacuum can be easily carried in one hand, but has the least capacity and power of any wet/dry vac. It’s best for small spills and small piles of dust or debris around the house or shop, but won’t handle larger jobs.

• Small: This size of vacuum trades tank capacity and power for portability and price. Best for smaller cleanups around the home and garage.

• Medium: Offering more power, overall performance, and capacity, this size of wet/dry vac is a good all-around appliance for most do-it-yourselfers to trade up to.

• Large: For shops that face challenging cleanups, this size offers the highest capacity and power. It can hold the most water, or a much higher amount of debris. However, it’s a bear to haul around, and may strain standard 120V electrical circuits.
   

But size isn’t everything. Buyers should also consider static pressure, airflow, and air power. These ratings, listed on the vacuum’s label, give buyers an idea of the machine’s capibility.

Static pressure (SP), also called “sealed pressure” or “sealed suction,” is an important measurement for vacs that will be used to pick up a lot of water. High-end wet/dry vacuums have an SP rating around 75.

CFM (cubic feet per minute) is a rating of the maximum airflow a vacuum can achieve at its largest opening. A higher airflow rating is important for vacs that will be used to pick up fine dust and other small particles.

Air power (AP) or air watts is a key rating for vacs that will be used to pick up heavier debris like nuts and bolts.

While a good rating for all three is important for any wet/dry vacuum, look for a balance that leans slightly toward a higher rating for the primary planned use. For example, a vacuum with plenty of horsepower and a very high airflow, compared to its SP or AP ratings, may be great for picking up dust, but not so good for vacuuming up nuts and bolts – its suction is too low. You’ll want the airflow rating to be more in balance with the suction and air power.

In addition to size, wet/dry vacs have a few other options that buyers may want to consider. If the vacuum will be used to pick up a lot of water, choosing one with a tank drain will make it much easier to empty the tank, rather than trying to pick up a large bucket of water.

Some wet-dry vacs include a blower feature – either a built-in port or a detachable blower. This is very handy for knocking dust out of the corners of the shop, or even clearing leaves from the driveway.

Most wet/dry vacs come with a hose attachment with a diameter of 1 ¼ inches, but wider hoses can be purchased.

Some small and mini vacs are capable of being wall-mounted. While this is great for storage and opening up floor space in the garage or shop, they’re not portable in this position. It may be hard to reach the far corners of the workshop, even with a long hose extension.

Wet/dry vacs are really loud, with some reaching 85 decibels, requiring ear protection. “Motor pitch can be annoying in single speed units,” says Rathey, so buyers may want to consider a wet/dry vacuum that has multiple speed settings. “Two speeds enable varying the power, sound and tailoring performance.”

Filters are likely the most important factor in getting the most out of a wet/dry vacuum. They need to be changed regularly, and it’s important to buy the correct size filter.

“Filters must be sized for the rate of airflow and the power of the unit,” says Rathey. “Wimpy filters allow lots of dust to get through and back into the air. Too much filtration slows down the air and interferes with the ability to pick up soil.”

Many wet/dry vacs have pleated cartridge filters, which are easier to change than two-piece paper/foam filters, and which trap dust much more efficiently. If your model doesn’t come with this type of cartridge, consider upgrading to a pleated filter.

Cleaning and drying the vacuum interior regularly is important, too, as a mix of organic soil (from vacuumed-up dust) and moisture can lead to mold and bacterial growth. Not only does that create a musty smell that affects indoor air quality, it can be a health issue.

To make cleanup a bit easier, and to reduce the amount of fine particles that escape the filter and re-enter the room, consider using a dust bag when vacuuming dry debris. The bag can be quickly removed from the chamber, making the vacuum almost instantly ready to switch over to wet vacuuming (with a filter change, of course). A dust bag can also help prolong the life of the filter.

For wet/dry vacs that are sold without them, bags are available for separate purchase. Be sure to buy the correct size for your vacuum, and avoid the temptation to purchase a “high performance” replacement bag without doing your research – most standard dust bags do a good job of catching fine dust and jagged or sharp objects without compromising suction.