PECO Air Purifier | Overview and Facts

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Written By Jamila W.

PECO air purifier technology is an emerging air-cleaning technology used in homes and large buildings. PECO uses photo electrochemical oxidation, known as PECO to degrade and destroy a wide range of substances that pollute indoor air, often out-performing filter-based indoor air cleaning technologies like HEPA. In this article, we explain:

What is a PECO Air Purifier?

A PECO air purifier is an electrically powered air cleaning device that is used to reduce levels of contaminants in indoor air. 

PECO air purifiers use photoelectrochemical oxidation to eliminate pollutants from indoor air. This electrochemical process involves the use of UV-A light and electricity to activate a catalyst that generates free radicals that efficiently destroy pollutants in room air. PECO air cleaners have shown experimental and real-world efficacy in destroying air pollutants that include:

  • Bacteria
  • Viruses
  • Molds
  • Airborne allergens
  • Cigarette smoke
  • Particulates including PM1, PM2.5, and PM10
  • Volatile organic compounds (VOCs)

PECO air cleaning technology 

PECO-assisted air purifiers are unique because they use an electrical current that potentiates the efficiency of the photocatalysis that generates hydroxyl free radicals from water vapor in the air. 

The high concentration of free radicals ensures that the elimination of pollutants is complete, without generating and releasing hazardous intermediate chemicals like formaldehyde and ozone.

They are particularly effective at destroying bioaerosols containing bacteria and viruses. This is because the oxidative reaction completely degrades DNA and proteins in aerosol microorganisms that come into contact with the activated photocatalyst. 

The history of PECO air cleaners

Dr Dharendra Yogi Goswami, a Professor of Engineering at the University of South Florida is the inventor of PECO air purifier technology. He developed PECO at the Clean Energy Research Center at the university for over 20 years. 

Goswami discovered that the use of electrical energy enhanced the generation of free radicals in a photocatalytic reaction. These reactive oxygen species were able to fully oxidize a wide range of gas and particulate organic air pollutants, leaving harmless carbon dioxide, water vapor, and minerals.

After establishing his theory on an experimental basis, Goswami moved to create a commercially viable air cleaner that was capable of a substantial reduction in air pollutants. He patented PECO in 2014, taking his invention to market under the trading name Molekule. In 2017 the PECO air purifier achieved FDA clearance as a Class II medical device. 

By 2018, Molekule had shipped over 30,000 consumer PECO air purifiers to US customers who gave largely positive feedback on their performance.

How Does a PECO Air Purifier Work?

PECO devices combine filtration and photoelectrochemical oxidation (PECO) to trap and destroy pollutants in room air. These powered devices have regulated air intake that moves indoor air over filters to trap inorganic particulates and the powerful PECO catalyst that breaks down organic pollutants into carbon dioxide and water vapor.

PECO air cleaners contain a pre-filter and a second catalytic filter. The hybrid catalytic filter has catalyst-coated fibers, maximizing the surface area for the photochemical destruction of air pollutants. Even a single pass of indoor air is sufficient to significantly reduce pollutant concentrations. [1]

Pros and cons of PECO air purifiers

glass window, home

PECO air purifiers have been a commercial success because they can achieve more efficient indoor air cleansing than conventional filter-based air purifiers. However, PECO air cleaning devices do have some limitations. Here are the pros and cons of the PECO air purifier:

Pros of the PECO air purifier

Here are some of the advantages of the PECO air purifier:

  • A PECO air purifier can eliminate particulates as well as gaseous organic pollutants: Photo electrochemical oxidation is extremely effective at degrading the molecular bonds in particle air pollution and gasses like VOCs.
  • PECO technology is less likely to generate hazardous intermediate chemicals: The addition of electrical current to the catalytic converting action of PECO filters helps the air cleaner to destroy pollutants, leaving no harmful remnants.
  • PECO air purifiers have replaceable filters: Unlike many competitor air filters and catalytic air cleaners, the pre-filter and PECO filter of a PECO air filter can be replaced. 
  • PECO filter technology is continuously innovated: Molekule continues to undertake research and development to update its PECO filter design and optimize its performance. 
  • PECO air cleansers can eliminate odors: Photo electrochemical oxidation efficiently destroys the organic gasses that cause a wide range of unpleasant smells in indoor environments.
  • The PECO air purifier does not produce ozone: The California Air Resources Board (CARB, 2018) has verified that the PECO air purifier does not produce ozone.
  • The PECO air purifier is capable of destroying ozone: The oxidative power of PECO air filters can even disrupt ozone, reducing its concentration in your indoor environment.
  • PECO air cleaners have an aesthetically pleasing design: Molekule has designed the PECO air cleaner with stylish minimalist detailing that keeps the unit unobtrusive.
  • PECO air purifiers are available in a range of formats: There are 3 types of PECO air cleaners,  Air Mini+ (portable), Air Pro (performance), and Pūrgo™ (industrial).

Cons of the PECO air purifier

Here are the key disadvantages of the PECO air purifier: 

  • A PECO air filter cannot remove radon gas: PECO air filters do not remove every type of air pollutant. Radon gas is an example of a serious pollutant that photo electrochemical oxidation cannot eliminate.
  • The blue light of a PECO air cleaner may be disturbing: PECO air cleaners emit blue UV light as they operate. This may be disturbing to some people. There is a dark mode for nighttime use of the PECO air cleaner where only the non-catalytic pre-filter operates.
  • PECO air purifiers are expensive: PECO air filters contain advanced air purification technology that comes at a premium. However, varied studies have demonstrated the efficacy of this type of air purifier, and features like replaceable filters increase the longevity of the unit.
  • PECO’s air purification performance claims have been legally challenged: In 2020, Molekule was the defendant in a class-action lawsuit regarding the veracity of its performance claims. The National Advertising Division also found that many of the metrics used by Molekule in PECO advertising campaigns are unsubstantiated. This is a particular challenge in the air purifier sector which uses emerging technologies that are not standardized or regulated by agencies like the Environmental Protection Agency.

Are PECO air purifiers better than HEPA air purifiers?

HEPA air filters are the industry standard for filter-based air cleaning, removing up to 99.97% of 0.3-micrometer particles. However, a HEPA air cleaner only traps the particulate air contaminants. It cannot destroy them.

PECO air cleaners not only contain a HEPA pre-filter for removing particles from indoor air but also use a secondary proprietary catalyst-coated filter for the destruction of particulates and organic gasses. Both filters are replaceable to optimize the performance of the machine over a prolonged period. 

You can learn more about the differences between PECO and HEPA air cleaners in the article “PECO Filter vs HEPA”.

Is PECO the same as PCO?

PECO and PECO are similar air-cleaning technologies because they use a UV light-activated catalyst to clean indoor air. However, PECO augments the efficiency of its catalyst with an electric current that massively increases the number of free radicals generated so that the destruction of air pollutants is more complete. PCO does not have this additional electric current, and in some cases, the destruction of organic gasses is incomplete generating harmful intermediate chemicals.

You can learn more about the differences between PECO and PCO air cleaners in the article “PCO vs PECO Air Purifier.

In conclusion


PECO air cleaning provides a safe and innovative approach to tackling the problem of polluted indoor air. PECO’s manufacturer undertakes ongoing research and development to improve the performance of its filters and catalysts. It is important to note PECO air cleaners are expensive, and the evidence for their performance is not independently verified. However, many property owners and building managers are experiencing a satisfactory improvement in air quality using this device.