Protecting commuters

A UK air-conditioning specialist has said it has successfully tested an air-cleansing system that can capture and kill anthrax and other biological hazards at record speeds.

News of the technology, developed by Energy Technique, came as fears mount of a biological attack on London’s tube network.

The Surrey-based company claimed its system, called UVGI, could eventually be installed in trains and aircraft, as well as being fitted into the air-conditioning units of hospitals and other buildings.

The firm will put the UVGI unit into commercial production following successful tests at the Defence Science Technology Laboratory (DSTL) at Porton Down.

The prototype unit used a combination of advanced filtration and UV light to destroy 99.9 per cent of bacillus subtilis spores, a replicant of anthrax bacteria. DSTL scientists certified the product as ‘significantly diminishing’ exposure to anthrax, TB and the MRSA ‘superbug’ which is a major hazard in many hospitals.

The process uses an electrostatic pre-filter that is bombarded with radiation from banks of low-pressure mercury halogen lamps. The lamps, which sit outside the airstream behind specially designed quartz screens, also irradiate a second filter designed to trap the very smallest particles.

According to Energy Technique, the key to UVGI’s effectiveness is the speed at which it can clean up significant volumes of air. The company said one unit is capable of handling 1,500m3 of air per hour. In comparison, a similar US-designed device unveiled earlier this year could only cope with 420m3 per day.

Joseph Tufo, managing director of the UVGI operation, said: ‘To be effective you have to get as much of the contaminant into the unit as soon as possible. There is no time to wait for a slow system.’

The first UVGI unit will be a portable version about the size of a small filing cabinet, which could be placed in areas such as hospital wards where a specific contamination problem exists. Energy Technique plans to create versions that can be designed into new buildings or retrofitted.

Along with its partner in the venture, UV specialist Suvair, the firm will also produce a unit suitable for use with circular rather than square air ducts. Circular ducts are the dominant form of air circulation mechanism used in transport networks. This would open the way for the device to be fitted into future aircraft, trains and ships.Apart from offering protection against high-profile viruses such as anthrax, the system’s developers claimed UVGI would also cut down on the spread of everyday bugs such as the common cold.

Tufo admitted that the current cost of the system would preclude mass installation, but claimed this would change. ‘It is a new technology, and initially we are not going to be producing a huge number of units,’ he said. ‘But if we can get into volume production value for money will increase.’

Tufo conceded that, for all its claimed effectiveness against bio-hazards, UVGI would not offer protection against airborne chemical threats. But the company plans to begin an R&D programme with specialists in chemical filtration in a bid to combine their technologies and produce an integrated unit that can deal with both.

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