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Last modified on Sunday, 21 November, 2021

According to a post featured in the 2007 edition of Professional Carwashing & Detailing Magazine, it’s possible and in fact, recommended to use a shop vac without its filter.

The writer goes ahead to explain that doing so helps to get maximum airflow and suction from the vacuum as long as you fill the tank with a few gallons of water.

This article and many others raise the question, can you use a shop vac without a filter?

The simple answer is YES, but it isn’t that straightforward. To understand why we don’t recommend using a shop vac without the filter despite it being possible, it’s important to look at how a shop vac works and what it’s meant to do.

How Does a Shop Vac Work?

A shop vacuum, also known as a bucket vacuum cleaner, is a powerful machine mostly used to clean woodworking shops, commercial buildings, and construction sites. While a shop vac works on the same principle as a regular home vacuum cleaner, it is built with a more powerful motor and superior suction, enabling it to suck any substance.

A shop vac can suck anything from stones, sand, lumps of garbage, nails, and wood pieces without breaking a sweat. This simple machine also enables you to work on a larger surface area because it’s efficient and powerful.

Most people don’t know that you can also use a wet dry vac to collect water or liquids. For example, if your basement is flooded after a storm or you have spilled a significant amount of water on your carpet, a shop vac can help suck all this water faster than a mop can. However, there are a few adjustments you have to make to the shop vac before using it as a water pump.

Does Shop Vac Need Filter and Bag?

shop vacs without a bag

As with any vacuum cleaner, a shop vac comes with a collection bag where all the debris and dust will collect once it’s sucked up, and a filter to act as the filtration system. Since the work of a vacuum bag is self-explanatory, let’s discuss the importance of a filter a little more.

What is The Function of a Filter in a Shop Vac?

use a filter with a hepa

Any vacuum cleaner needs ample airflow and suction to suck in all that debris and dust. The only way that’s possible, however, is if the pathway is completely clear of any dust or clogging. A filter ensures this by catching all the fine dust and protecting the pathway from clogging.

Without the filter, the vac would have little airflow, affecting its suction capacity and eventually ruining some parts because of clogging. What’s more, the vacuum cleaner would blow all the dust you have collected back to the environment through the exhaust system.

Best Way to Use a Shop Vacuum without a Filter

With that understanding of how a shop vacuum works and the importance of a filter, we can now move on to different ways to use a vac without a filter.

1. Wet Vacuuming

wet dry vacuum

The number one way and possibly the only recommended way to use a shop vac without a filter is when you are vacuuming wet places or using it as a water pump. As we have already pointed out, the job of a filter is to prevent dust from passing and going inside the vacuum. When you are cleaning liquids or wet surfaces, there is no dust; hence a filter is unnecessary. In case you decide to leave the filter in place, chances are it will get ruined by the liquid or moisture, so it’s better to remove it first.

2. Using Water

The second way you can possibly use a vac without a filter is to use water as the filtration system instead of a filter. This is the precise method explained in that Professional Carwashing & Detailing magazine, but it’s not full-proof. The idea here is to fill the vacuum cleaner tank with a few gallons of water once you have taken out the filter. Once you suck in your debris, the water will effectively catch the dust and allow the solid debris to pass to the collection bag.

People who use this method claim that it helps improve the vacs suction capacity and airflow. While that’s debatable, the method has one simple advantage; it allows you to work more without the need to change filters. This helps if you have a big job to do and plenty of dust, especially in construction and woodworking sites.

cartridge filter

Unfortunately, this method will not catch fine dust, so it’s not a full-proof way to protect your machine and maximize its output. Despite it being a genius idea, using a dry vac without the filter will eventually cause more harm than good to internal parts. If you decide to utilize this strategy, use the vacuum in an open space or outside because the vacuum will throw back some of that dust to where you are cleaning.

As a note, not all shop vac models can work without a filter; make sure to check the instructions before you try any of these methods to avoid destroying the machine.

How to Improve the Performance of the Filter?

improve performance for drywall dust and dirt

As we have seen, a filter is a crucial part of a shop vac. The first part of improving its performance is choosing the right filter. For wet cleaning, go with a foam sleeve filter that will not be ruined by moisture.

On the other hand, when cleaning dry surfaces, you must attach a dust bag to collect most of the debris. In fact, you can’t use your vacuum without a bag. You can also clean the filter and the filter cartilages regularly if it’s something that can be cleaned and also change it following the manufacturer’s instructions.

Frequently Asked Questions

1. What happens if you use a shop vac without a filter?

The short answer is, you will reduce the lifespan of your shop vac. While it’s possible to use a shop vacuum without a filter when vacuuming wet surfaces or using water as filtration, these methods do not fully protect the machine from clogging and eventually breaking down.

Another thing that may occur if you use the wet dry vac without a filter is dust blowing back up on your face. The filter plays a significant role in preventing dust from getting into the vacuum’s components and coming back through the exhaust. Getting rid of it will make what you are doing useless because most of the dust will go back anyway.

2. Can you use a shop vac in standing water?

Yes and no. Yes, because you can use a shop vac as a water pump when you have a small flood in the house or outside. All you need is to remove the filter (if the manufacturer’s instructions allow) and dust bag, and connect the vacuum to a hose where the water will pass through as it goes out.

However, you cannot use a shop vac to suck a lot of standing water. If you are thinking of swimming pool water, ponds, and boreholes, the vacuum isn’t strong enough to get rid of all that water, and you could end up breaking it.

3. Why does my filter keep blowing dust back?

A couple of reasons could cause this; one, the filter is not installed correctly, and two, there is a hole in the motor or the filter itself. You could start by checking these two and changing the filter if it’s not new. However, the reason could also be that the dust you are sucking is too fine or smooth, in which case you will need a filter with a high-efficiency disposable bag.

4. Do I need a filter for wet vac?

The role of a filter is to stop dust from blowing back out when cleaning and going inside the vac. If you are cleaning wet surfaces however, you do not need the filter. It’s recommended you remove the filter when doing a wet vacuum to avoid damaging it. That said, some vacuum cleaners come with a foam sleeve filter which you don’t need to remove because it protects debris from ending up in the motor.

About the author

Hello there, I am Brad “Omni” Smith, the proud founder and chief editor here at OmniHomeIdeas.com. So, while they say, „Home is Where the Heart Is“, we believe that home is where every story begins. If you’re passionate about the nest that you call home, join us at Omni Home Ideas.
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