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Methods for Countering Airborne Biological Contaminants.

According to published reports, workers in our highly technological society now spend close to 90% of their time indoors. The U.S. Environmental Protection Agency (EPA) estimates that our exposure to pollution may be as much as five times greater indoors, than outdoors!

But, the microbiological quality of air contained within an air recirculation system can be significantly improved in many cases thereby increasing the chances we can avoid getting infections.  The air we breathe has the ability to host several fast-growing microorganisms, or bacterial strains that can be harmful to humans.

Elimination of biological contaminants (e.g., microorganisms, protozoan, spores, moulds and viruses etc.) from air is difficult and cannot be totally achieved, but, the contamination can be significantly reduced when treated at the point of air delivery – near its point of use.

Ultraviolet radiation has been in use for over 100 years to treat human disease and neutralize harmful microorganisms. Ultraviolet sterilization is a proven method of eliminating a variety of harmful airborne microorganisms. Short-wave ultraviolet light (e.g., 200-300 nanometers) kills airborne microorganisms with ease, providing they are exposed to the radiation for a sufficient length of time. It had not, however, until now been applied to a moving stream of fluid. In the case of air treatment, SALtech will apply a UV laser–borne beam in the killing zone to change the DNA & RNA of undesirable biological contaminants and render them harmless. With SALtech’s technology, air enters a treatment area near the point of use, generally after some type of filtration. 

The air and microorganisms contained therein are subjected to light from a UV laser source. This treatment area uses free flowing multi baffled chamber of UV laser diodes, design to expose organisms to a UV laser source, which increases the exposure time, thus providing adequate time to neutralize the microorganisms. As the air passes through the treatment area, the microorganisms contained within the air are reactive to light of a predetermined wavelength, as photons of UV energy are absorbed by the DNA, the base-pair hydrogen bond is ruptured causing disruption in the DNA chain.  This simply means that when the cell undergoes mitosis, the DNA is not able to replicate, thereby rendering the microorganisms harmless. Unlike chemical disinfectants, the organism is unable to develop any immune mechanisms.  With the bacteria, spores, viruses, molds or protozoa neutralized, air is then provided to its point of use, clean and safe. No other air purification is more effective at neutralizing micro-organisms than ultraviolet light radiation. Ultraviolet light possesses just the right amount of energy to break organic molecular bonds. As micro-organisms pass by the UV rays radiated from an ultraviolet source, this bond breakage translates into cellular or genetic damage for micro-organisms, such as germs, viruses, bacteria, fungi (like molds), etc. This results in the destruction of the micro-organisms.

UV Lamp Technology

It is known that germicidal lamps (UV lamps) will technically “kill” infectious microorganisms in water by neutralizing their infectivity, the same principle is applied to air applications.

Problems associated with UV Lamps

¨      Fluorescent Lamps have been the only source of commercially available UV light.

–        No micro- or nano-technology capabilities

–        Floodlight, omni directional output is difficult to concentrate or direct  as well as

–        Excess Heat generated by absorption of non-germicidal wavelengths

–        UV lamps take several minutes of warm-up time

–        High Failure Rate due to high temperature leading to mechanical failure

–        UV Lamps have a limited Lifetime: < 10,000 hours, decreased by higher on/off duty cycles

–      “Single-line” output lamps still emit 10 nm (Full-Width Half-Max) band at a lower efficiency than broadband lamps.