How Long to Run an Air Scrubber: A Quick Guide

When it comes to using an air scrubber to help to purify your home, workshop or business, the first concern on most people’s minds is how long to run it for. How long does it take for an air scrubber to do its job? 

There are multiple factors that affect how long an air scrubber will take to purify the air, but there are a few general guidelines that most professionals follow. 

Whether you’re new to air scrubbing or are upgrading to a new HVAC, here’s our complete rundown on how long to run your scrubber system – based on expert opinion!


How long should I run my air scrubber for?

When an air scrubber is used to remove mold and other polluting elements in the air, most professionals run them for between 24 and 48 hours. They may also use air scrubbers that run between the 400 and 600 CFM range and assume between four and six air changes per hour (ACH). 

Of course, not all jobs can be completed in such a small amount of time and may require further scrubbing – it really does depend on what you need to scrub, and the size of area you are working with!

Therefore, it makes sense to look at CFM and ACH before you buy, as well as to consider powering on your HVAC and air scrubber for up to 48 hours if you have a lot to clean out. However, as always, make sure you follow your manufacturer’s guidance – their lead is important.

Investing in air scrubbers is always worth it for the hard work they do, so don’t risk doing any damage by running them against the manufacturer’s advice.

What do I need to consider before starting my air scrubber? 

Aside from working out the amount of time you should run a scrubber for, you should make sure you know what you’re getting into! Although it may seem easy to just plug in an air scrubber and let it run, there are a few things that you will need to consider before doing so.

The size of the space

Obviously, the bigger the room, the more air will need to be scrubbed. Although many assume that having one air scrubber running for the suggested amount of time will do, you may actually need more than one scrubber to clean up properly.

Filter condition

Air scrubbers won’t work nearly as well with a dirty filter. That much should be obvious! The general rule of thumb is to run the air scrubber (at the very least) at over 50% filtration capacity. If you are running an air scrubber on an old filter, those microbes are going nowhere fast.

Area condition

If you are renovating an old building, then chances are that you’re probably dealing with thick mold, dust and more. If that is the case, then using your air scrubber for the recommended amount of time will not do. 

Although air scrubbers are recommended to run for between 24 to 48 hours, a particularly moldy area can take far longer to clean – potentially up to a week. Remember that the longer the air scrubber is running, the more it will be taking in. 

That means that you will need to check the filter of the air scrubber during its active time to ensure that it is still clean enough to do its job. Even the best HEPA air scrubbers will need care and attention!


Calculating the exact amount of time it will take for your air scrubber to properly clean up your air depends on quite a few different factors. Yes, the general idea is that 48 hours of continuous scrubbing should be enough – but we all have different homes and premises to clean!

Therefore, make sure to check out your operating manual and to take into account your space and filter condition before running. Different types of air scrubbers will vary in terms of effective time, too – so take care to plan ahead.