ASHRAE Position Document

ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers, is an organization that promotes standards related to the HVACR industry. The recent ASHRAE Position Document on Filtration and Air Cleaning will have far-reaching consequences for the HVACR industry. Pertinent excerpts below.


PCO Technology Works

Section 2.3 - Air Cleaners Using Photocatalytic Oxidation

“Chemisorbent media positioned downstream of a UVPCO air cleaner effectively counteracted the generation of aldehydes due to incomplete oxidation of volatile organic compounds (VOC) in UVPCO reactors.”


“The photocatalyst generates oxygen species (or reactive oxygen species [ROS]) that remain surface-bound when exposed to light of particular wavelengths in the ultraviolet (UV) range. The oxygen species are highly reactive with adsorbed gases and biological particles.”


“Nearly all organic, gaseous indoor air contaminants and microbes are subject to PCO decomposition”


UV-C Disinfection

Section 2.4 - Air Cleaners Using Ultraviolet Germicidal Energy (UV-C)

“The effectiveness of a UV-C system to inactivate microorganisms in the air and/or on surfaces has been amply demonstrated; the best results were obtained for the long-term irradiation of downstream coil surfaces to avoid fungal amplification on wet surfaces.”


Ozone is Harmful

The ASHRAE document also calls into question the safety and effectiveness of technologies that broadcast ions, ozone, and other species of airborne oxidizers into the occupied spaces of buildings.


Section 2.6 - Ozone-Generating Air-Cleaning Devices

”Ozone is harmful for health and exposure to ozone creates risk for a variety of symptoms and diseases associated with the respiratory tract”; “Ozone emission is thus undesirable”.


“The current state of the science regarding the health effects of ozone strongly suggests that the use of air cleaners that emit ozone by design should not be permitted; the same information and advice is given by the U.S. EPA, among others (EPA 2013)”.


Reactive Oxygen Species

Section 3.2 - Positions on the Use of Filtration and Air-Cleaning Devices

“Attention must be paid to certain air-cleaning technologies that claim to produce radicals (e.g., hydroperoxy, peroxy, and hydroxyl radicals) that become airborne (gaseous state) as a means of effecting air cleaning/treatment. These species are ROS and are well known to be very short-lived in the gas-phase (airborne). Few studies in the peer-reviewed literature, if any, have measured these radicals in the gas phase as a means of an effective air treatment with such air-cleaning technologies”.

Fresh-Aire UV - Ozone Free

Our History with Ozone-Related Products

Triatomic Environmental Inc., our parent company, was founded in 1988 as a manufacturer of ozone machines. In fact the name "Triatomic" is a reference to ozone which is a triatomic molecule. These machines, some of them quite large, were intended for use in unoccupied spaces where odors are a problem such as locker rooms, kennels, rest rooms etc. or where fire and flood problems have occurred (which are still valid uses for ozone-based disinfection). In the 1990's duct-mounted ozone based devices became popular for central HVAC air treatment for odor control.

Triatomic ozone machineIn 2001 the company came under new ownership. Considering the experiences and pitfalls of the previous owner's ozone based product line, the new owners sought to find a better approach to indoor air quality treatment.  This lead to the creation of an innovative line of germicidal UV lights for HVAC applications and Fresh-Aire UV was born. Over the next decade the HVAC industry came to accept UV light disinfection as a better approach for mold and mildew mitigation over ozone based duct-mounted systems.

APCO is the Ozone Alternative

APCO whole-house air purifierIn 2008 our team of product development engineers overcame the limits of traditional PCO technology by pioneering the use of activated carbon instead of metal as the activation media. This has proved to be highly effective. The new product line was named APCO for Adsorptive PhotoCatalytic Oxidation. APCO won the 2011 AHR Innovation Award for indoor air quality and has become one of our best-sellers. APCO not only neutralizes odors without producing ozone, it actually removes ozone from the air! (see chart)

APCO removes ozone (in red) from the air

Carbon cell with UV LightIn order to safely remove odors from the air without using 185 NM ozone-producing UV-C light an alternative technology was needed. Although highly effective against microbes 254 NM UV-C light (which does not produce ozone) has little direct effect on odors. It can, however, be used as the light-source in a reaction called photocatalytic oxidation or PCO. PCO neutralizes odor-causing (and potentially toxic) volatile organic compounds.


Our UV Lamps Are Ozone Free

Our UV-C lamps are certified ozone-free