The technology incorporated into the HELIOS™ air treatment systems was developed to sterilize the air rather than purify it. By maximizing both the UVGI output, and the effective photocatalytic surface area we were able to achieve a 99.9% destruction rate for microorganisms, without the use of HEPA filters, and a significant first pass reduction in VOCs, without the use of activated carbon filters (VOCs can be large molecules, and will sometimes require multiple passes through unit to eliminate completely).
Ultra Violet Germicidal Irradiation (UVGI)
A dosage of 3,000 microWatt-seconds/cm2 is sufficient to kill/deactivate up to 99% of many common microbes. Viruses are much more susceptible to UVGI than bacterial or mold spores, due to their much larger surface area to volume ratio. When microorganisms (including all viruses, bacteria and fungal spores) are exposed to sufficient UVGI it destroys their nucleic acids and disrupts their DNA, leaving them unable to perform vital cellular functions and rendering them harmless or inert.
Photocatalytic Oxidation (PCO)
During the 1980’s and 1990’s intensive scientific and commercial activity followed the discovery that ultraviolet light shining on photocatalytic materials produced free-radical species and positively charged “holes” at the photocatalyst surface that aggressively and efficiently destroyed organic molecules, converting them into carbon dioxide and water (the reverse of photosynthesis). This process is commonly called photocatalytic “oxidation” or “PCO” even though both oxidation and reduction occur. The efficiency of the PCO process is dependent upon (a) the wavelength and intensity of the UV light, and (b) the surface area of photocatalyst exposed to the UV light.
Our Photocatalytic Oxidation (PCO) Elements
Our Photocatalytic Oxidation (PCO) Elements consist of high quality stainless steel weave with anatase titanium dioxide, which creates an enormous photocatalytic active surface to maximizes the amount of VOC and pathogen destruction.
Most air purifiers only capture pathogens, but the HELIOS™ series use three powerful UVGI chambers and patented photocatalytic elements to destroy virtually all airborne pathogens.
The incoming air goes through a washable pre-filter that has special ultraviolet light resistant properties. The sole purpose of the pre-filter is to ensure that the permanent photocatalytic elements within the HELIOS™ systems remain uncontaminated with dust, lint or other larger particles present in the air. This ensures that the light transmission through the photocatalytic elements remains unimpeded. Frequent cleaning of the pre-filter is recommended to ensure proper air flow – about once every three months. The unit has been equipped with a sensor to indicate when the filter is approaching a clogged state that is detrimental to the HELIOS™ system’s operation. If left unresolved the unit will shut down and won’t turn back on until the filter has been cleaned.
Ultraviolet Germicidal Irradiation (UVGI)
Ultraviolet Germicidal Irradiation or “UVGI” is electromagnetic radiation that is in the ultraviolet light spectrum. The UVGI is generated by mercury vapour bulbs, specially designed in cooperation with a UVC bulb manufacturer, to deliver these wavelengths without any ozone production or transient/unwanted odours. When microorganisms (including all viruses, bacteria and spores) are exposed to sufficient UVGI it destroys their nucleic acids and disrupts their DNA, leaving them unable to perform vital cellular functions and rendering them harmless or inert. The HELIOS™ air treatment systems have been designed with 72 – 216 watts of UVGI to maximize the cumulative irradiation the microorganisms are exposed to and facilitate their destruction.
Permanent Photocatalytic Elements
The HELIOS™ UVC Air Treatment systems have been designed with four photocatalytic elements with direct exposure to UVC light in a laminar flow arrangement. This means that all contaminants in the air stream must pass through an element four times. These photocatalytic elements consist of high purity quartz High quality stainless steel (UVC conducting) wool coated with a photocatalyst (anatase titanium dioxide) to create an enormous photoelectrically active surface area that is all fibre-optically accessible to the UVC light. The photons of the energetic UVC light striking the photocatalyst’s surfaces causes electrons to be ejected, leaving positive “holes” behind.
The released electrons and created “holes” cause oxidation and reduction reactions (including the creation of aggressive, extremely short lived, hydroxyl free radicals) that convert all the volatile organic molecules (odours) that they come in contact with into carbon dioxide and water. This further deactivates and converts all microorganisms surviving the UVGI dosage. The tangled mass of fibres in the quartz wool Tight weave of the stainless steel mesh assures that there are many surface contacts experienced by the molecules and microorganisms upon passage through each of the four elements.
The conversion process indicated above, that takes place at the nanoscale, reduces the ejected electrons energy and it drops back into the hole that was created upon the UVC photon strike. This self regeneration characteristic is what makes the photocatalytic elements permanent and able to last a lifetime.
Sterilized Air Flow
A powerful, yet quiet, industrial fan pulls air into the HELIOS™ systems at a rate of 90 – 250 cubic feet per minute while on high speed (which means that most of the air in an average room will move through the unit in about twenty minutes). The fan speed can be manually set at one of 4 speeds and can be set to slow down (quieter operation) to a programmed preference when motion is detected in the room. When no motion has been detected for 90 minutes, the fan speeds back up so that the room’s air is sterilized more quickly and ready for people when they return.