What is the difference between air purification, air sanitization and air filtration? A few “air” terms in cannabis cultivation are frequently misunderstood by new home growers. Specifically, “air purification,” “air sanitization,” and “air filtration.”
Let’s get these concepts sorted out.
The terms air purification, air sanitization and air filtration aren’t all interchangeable. Although air purification is the same as air sanitization, air purification and air sanitation are different from air filtration. Air filtration is different because “filtration” is limited to the use of filters. Filtration works by “trapping” spores, as compared to neutralizing and killing the spores — as with more advanced sanitation / purification technologies like Photocatalytic Oxidation (PCO).
It’s air purification and air sanitization VS. air filtration. What is the difference?
Air Filtration Explained
The most common home grow filters used in grow rooms and grow tents are HEPA Filters and Carbon Filters. Filters of course don’t last forever and should be changed regularly, minimum yearly, if not much sooner due to dust load.
A 100% HEPA Filter (True HEPA) will capture air pollutants and pathogens like bacteria, mold, mildew, dust, etc., The challenge lies in the fact that a 100% HEPA filter is hospital grade and extremely expensive. The non-hospital grade filters, which companies will market as a HEPA filter, have a varying % of HEPA in them and thus also have a varying degree of effectiveness. Carbon Filters are not designed to capture spores. They capture odors instead. Carbon and HEPA are two different filters with benefits, but also many limitations. If you are using a HEPA Filter or Carbon Filter, you are practicing air filtration, not air purification or air sanitization.
The motivation of someone using HEPA Filters is to prevent plant pests & disease in their garden. The motivation of someone using Carbon Filters is to eliminate odor. If you don’t want your neighbors catching wafting whiffs of your cannabis garden, you would use a Carbon Filter. If you have a hard time keeping plant pests or diseases out of your home grow, you can HEPA filters of good quality – just keep in mind many of these filters are moderately effective, but not a silver bullet. There are no silver bullets in cannabis pest / disease prevention and control.
The best practice is to use a HEPA Filter in conjunction with an air purification/sanitation system.
Be forewarned. With Carbon Filters, once a filter is clogged and has exhausted itself, it will release everything it absorbed right back into the air. You’ll need to be very careful to not let your Carbon Filter back-fire on you. But if you aren’t concerned with eliminating the smell from your home grow, there’s no need to use a Carbon Filter.
Today in cannabis cultivation, there are even some air filtration systems that offer both HEPA and Carbon Filters, but they would not fit in a small home grow tent. A commercial grow room might be more compatible; however, as mentioned above – there are limitations.
Air Purification / Sanitization is all about cleaning the air by completely destroying and obliterating contaminants, pollutants and pathogens – not capturing them as a filter would.
There are primarily three different types of air purifier / air sanitation units on the market – each ultimately utilizing either photocatalytic PCO, UV Light, or Ozone.
One problem with air sanitizers/purifiers that generate and use Ozone as their killing mechanism, is that Ozone is harmful to the plants as well as harmful to humans according to the American Lung Association and American Heart Association. Manufacturers of these types often try to disguise the name Ozone by calling their system: “Activated Oxygen, O3, Hydrogen Peroxide Ions, Activated Ions,” etc. Regardless, free-floating oxidants will come into contact with your plants as well as anyone who happens to be in the area.
A challenge with UV Light systems is that they can very ineffective due to contact and dwell time of air passing through the units.
Photocatalytic Oxidation (PCO) technology has been used in agriculture, cannabis, hospitals, NASA, as well as many other industries. It is the strongest and safest way to clean air. Photocatalytic Oxidation (PCO) is cutting-edge technology that cleans air and was originally created by NASA scientists.
AiroClean420, a NASA Developed, air purification units use PCO technology and does not produce any emissions at all, unlike many other air sanitizers / air purifiers. AiroClean420 units are for use in grow rooms (AiroClean420 Commercial Model) or grow tents (AiroClean 420 Home / Hobby Model) and use less than 2/1 amps of power at 110 volts depending on the model.
Why don’t they create emissions? It’s technical, but here it goes. According to AiroClean420, they “utilize nano particle science to make a titanium oxide membrane that is photocatalytically active, which also binds to the applied surface(s) without any delamination, further, nanotechnology comprises technological developments on the nanometer scale, usually 0.1 to 100 nm, or ten thousand times smaller than the width of a human hair.”
In layman terms, each AiroClean420 unit has a fan and a bio-conversion reactor bed that contains the above-mentioned membrane (catalyst). The bio-conversion reactor bed utilizes a proprietary light source (UV Light) to excite this catalyst – once this occurs then Hydroxyl Radicals are formed on the surface of the catalyst. Then as the environment’s air is pulled through the bio-conversion reactor bed – anything organic – powdery mildew, bacteria, pollen, voc’s, other fungal diseases – all get killed. The result? Virtually pure air. The only bio-products being trace elements of CO2 and water vapor.
The reason AiroClean420 is listed as an FDA Class II Medical Device is because all of its “kill” happens within the bio-conversion reactor bed.
The above-mentioned Hydroxyl Radical is surface bound and held to the surface of the catalyst. So there are no emissions or harmful chemicals or gasses generated (or used.) This surface bound hydroxyl radical is the same oxidant as used in ozone (the PCO version is slightly more powerful). However, the main difference is that the Hydroxyl Radical used in Ozone is Free Floating and oxidizes anything that it comes into contact with – thus, rendering it not safe and needing OSHA exposure limits. The Hydroxyl Radical produced by PCO is surface bound and isn’t emitted into the facility or grow room or grow tent.
In conclusion, for best results in your home grow, practice good air purification/sanitization and filtration, (but don’t forget to do your foliar sprays for pest prevention too.) Remember, carbon filters are quite effective for absorption of odor from a grow room, especially if it’s a truly sealed grow room. And HEPA Filters can help mitigate the likelihood of plant pests and diseases in your home grow. Air Purification Systems that use PCO technology with no emissions like AiroClean420 are the best to prevent powdery mildew and other airborne plant viruses and diseases.