What is the difference between an Air Scrubber and Air Purifier?

In these days of heightened concern over viruses, bacteria and other air-borne toxins, knowing how to clean the air around you is important. Gone are the days when we could just open a window and declare it “good enough.” Now, it’s more important than ever to make sure that the air you breathe is safe and as free from contaminants as possible.

To do this, there are a number of products on the market. When it comes to air quality, most of these products fall into one of two categories: portable air purifiers and portable air scrubbers. You might not realize it, but these two types of machines work very differently in trying to clean the air around you. Knowing your needs can help you go a long way towards choosing the right product for your situation.

Air Purifiers

When most people think of improving their air quality, they think of portable air purifiers. This is because these purifiers use a filtration system which is similar in some respects to the air filters you might find in your home HVAC system. With an air purifier, air is dragged through one or more filters, which literally block particles that are too big to pass through the mesh screen of the filter.

Different filters are available to screen out particles and contaminants of different sizes, so it’s easy to upgrade your filters if you feel like the one you have in place isn’t doing a good enough job. Of course, you also have to know that the higher-quality filters, which filter out smaller and smaller particles, also create more drag in the purifier itself. This drag comes because it takes longer for the air to squeeze through the smaller and smaller holes in the mesh screen. Some purifiers struggle when there is too much drag, so it’s important to know what your purifier is rated for.

Air purifiers can range in size from very small, personal machines to much larger ones capable of working on larger rooms. However, portable air purifiers have a limit due to the amount of air that can pass through the filters at any given time. Obviously, larger spaces take longer to clean.

Pros and Cons of Purifiers

Because purifiers can catch the tiniest of particles (down to .3 microns in size) they are extremely effective at cleaning the air, provided the space is not too big. Air filters not only remove particles, the right types of carbon filters can also be very effective at removing odors such as cigarette smoke and pet smells. However, one thing air purifiers do not handle well is contaminants in the form of gas. When you are dealing with gases in the air, it’s better to look at a portable air scrubber.

Air Scrubbers

At first glance, it might seem like there’s not much difference between portable air purifiers and scrubbers. Yes, it’s true that they both typically use filtration technology to help clean the air. However, that’s where the similarities end. While purifiers rely on the mechanical action of stopping particles and contaminants over a certain size, air scrubbers use chemistry.

If you took high school chemistry, you may remember that atoms, the smallest basic unit of matter, are made up of particles called protons, neutrons and electrons. These particles carry charges of either positive or negative energy. While an atom is, typically, neutral, atoms called ions exist that carry either a positive or negative charge.

One of the basic principles of this is that charged ions are always looking for equal, opposite charges to balance themselves out. So, positively charged ions are looking for negative ions, and vice versa. This action causes many natural phenomena, such as lightning, but in this case it can also help us clean the air.

How? It turns out that most air contaminants are positively charged. Knowing this, air scrubbers work by using negative ions. As air passes through the scrubber, the negative ions bond with the positively charged particles, causing them to fall out of the air, basically, into a collecting surface.

However, not all air scrubbers use filters. Some actually send out sprays of these negatively charged ions (in the form of a hydrating mist, for example) which can actually just bond with participles in the air, or on surfaces such as walls. Either way, the result is the same: the now-neutral particles are much heavier and fall to the floor, where they can easily be cleaned later.

The Pros and Cons of Air Scrubbers

Just like purifiers, there are good and bad points to this technology:

• One good thing about scrubbers is that they work on gas-related contamination, which is something that air purifiers just don’t do. So, if you need gases scrubbed out of the air (like CO2, for example) air scrubbers are the way to go. They can also work in larger areas.
• On the downside, air scrubbers are not effective when it comes to removing odors. So, while they may be able to remove cigarette smoke from an area, the stench of the cigarette will remain long afterwards, and the scrubber is unable to remove it.

As you can see, purifiers and scrubbers are both great ways to help clean up the air you’re breathing. Which one you might want, however, will depend on what you’re looking to clean. If you’re in a smaller space and mostly worried about dust and other physical contaminants, or if you have smells you need to clean, then air purifiers might be the better option. On the other hand, if you’re dealing with gas-related contamination, or if you’re hoping to clean a larger space, then an air scrubber might be what you’re looking for.