Air filter neutralizes viruses and bacteria

 - October 4, 2007, 7:01 AM

In recent years, much has been made of the potential danger presented by the recirculation of aircraft cabin air that may be bearing viruses and bacteria.
UK-based Microgenix now says it has an answer that is close to 100-percent effective against harmful viruses and bacteria, has no moving parts and is light in weight and low in cost.

Microgenix began actively promoting its combination filter/UV treatment system to airlines last month. According to a company spokesman, “We can down-scale the system to fit a Falcon business jet, and our next market will be business aviation.” The system has been in development for about two years.

A Microgenix unit capable of filtering and treating cabin air for pathogens in an aircraft the size of a Global Express weighs barely 20 lb, fits neatly into the existing duct system, has no moving parts and is priced at about $14,000 per unit (uninstalled).

A cockpit monitoring box features lights confirming operation of the system and six additional lights to confirm that each of the UV bulbs is functioning.

The key to the device is a two-stage system to eliminate airborne pathogens. The first is a series of three Biogreen 3000 metal filters. Each is coated with a liquid that dries to create a microscopic surface of hundreds of thousands of small “spikes.”
When airborne microorganisms come into contact with the treated filter surface, their cell membranes are pierced and they are rendered harmless. Filtered air then passes through fixed impeller blades, which create a vortex within the UV light chamber to increase the “dwell time.” This ensures that any bacteria or viruses that might have evaded the filters are neutralized by altering their DNA structure.

During tests by military biological warfare specialists, the system proved 100-percent effective against simulated anthrax spores. “They put eight million spores through in one second and all of them were destroyed,” said the Microgenix spokesman.

Existing cabin-air circulation systems use engine bleed air to mix fresh air with up to 50-percent recycled air, which is passed through HEPA (high-efficiency particulate arresting) filters. When these filters become clogged, their effectiveness can be substantially reduced, and the HEPA filter must be replaced as often as three times a year.

Even assuming 24/7 continuous operation, Microgenix suggests replacement of its components–filters and UV bulbs–only once a year, at a total cost of about $300. This can be done at the same time as the suggested annual maintenance check, which is performed primarily to ensure that the monitoring system is working.
Because any bacteria or virus remaining in the filters have been rendered harmless, the used filters do not constitute a biohazard and can be disposed of in any trash receptacle. In fact, they can be washed in a solution provided by Microgenix and reinserted. The entire maintenance and component replacement process can be done in less than 30 min.

The Microgenix system could help airlines save money by reducing the intake requirement for fresh air and the energy required to force air through the filters.
While the company has yet to take its first aviation order, it is already beginning to provide the systems for installation in buildings such as hospitals and military installations.

As a company, Microgenix actually consists of only three employees in a small south London office– founder and managing director Phillip Hall, Bridget Handley in administration and spokesman Daryl Poland. Production of the air-purification units is subcontracted to Parc Engineering of West Sussex, UK. Microgenix is looking for a U.S.-based licensee to cover the North American market.