PCO vs. HEPA in Grow Rooms

Molds, pollen, insects, and bacteria are the four major threats impacting indoor grow environments.

A properly designed grow room air filtration system will prevent powdery mildew, cross-pollination, and keep airborne dust and insects from settling on the canopy. But what technology is right for you?

Choosing between HEPA and PCO technologies can be difficult with the overwhelming amount of conflicting information available.

CleanLeaf air cleaner installed in a grow facilitiy.

The Truth About PCO

Although PCO has proven effective in stationary applications, there are serious concerns regarding efficiency, particulate removal, and harmful by-products from the unfinished breakdown of VOC’s in airflow applications.

In order for VOC’s to be completely broke down into harmless carbon dioxide and water, the UV light, catalyst, and speed of the contaminated air must be perfect to produce any sort of significant efficiency.

Most alarming, the by-products from the unfinished breakdown of VOC’s during testing have produced up to 4x the amount of Formaldehyde in the air, a known human carcinogen.

A 2015 Concordia University study summary concluded, “Imagine if, in an effort to clean the air more efficiently, you were involuntarily introducing chemicals more dangerous than the ones you were trying to scrub. Researchers have found that this exact situation is happening with a type of air filter called photocatalytic oxidation, a product already on the market.

With product testing becoming the norm, keeping airborne dust and mold off the plants is critical; something PCO technology is not designed to do. Although some pollen and mold will be killed via photocatalytic oxidation, the particulate remains in the air.

Why Choose HEPA

HEPA filters trap airborne particulate within the filter, creating a surgical level clean room environment.

According to the EPA summary of PCO air cleaners, “PCO cleaners use UV lamps along with a substance, called a catalyst, that reacts with light. These cleaners are designed to destroy gaseous pollutants by changing them into harmless products, but they are not designed to remove particulates. The usefulness of PCO cleaners in homes is limited because currently available catalysts are ineffective in destroying gaseous pollutants in indoor air.”

High-efficiency particulate air filters (HEPA) were originally designed in the 1940’s for the Manhattan project, where the first atomic bomb was developed during World War II. A major advancement in air filtration technology, the filter solved a critical need to control very small particles which had become contaminated by nuclear radioactive sources.

Also known as absolute filters, they remove 99.97% of particulate down to .3 micron, the major threats to indoor grow rooms being 1 micron and larger.

For reference, the human eye cannot see anything under 40-50 micron. Due to its effectiveness, HEPA filters have become the standard for any process requiring the ultimate in air filtration.

Although PCO technology has proven effective at preventing mold growth within the HVAC duct, the possible negative health effects and low efficiency make HEPA filtration the superior solution for indoor grow rooms.