Clean air technology

A new means of purifying air based on a simple electronic device could mount a significant challenge to established players such as ultraviolet light and HEPA filters, writes Phil Taylor.

The technology, developed by start-up company Kronos Advanced Technologies, combines high voltage electronics and electrodes into a simple electrical device that, with no moving fan blades, electric motors or filters, can silently move and clean air.

As a result, it is quieter than fan and filter technologies such as HEPA systems, and should be cheaper to run, as it will not have the associated expense of powering the fan and routine maintenance and changing of the filter units. The system could be of great benefit to food processing applications that require the use of a cleanroom.

In addition, Kronos' technology also has advantages over electrostatic precipitators, which work by charging particles in the air stream as they pass through the air cleaner, which causes them to be attracted to an oppositely charged collection filter.

These are quiet, do not need filter replacements and require less energy to run. However, they do require a fan, give off a crackling sound as the filter accumulates dirt and produce ozone, which has a noticeable smell similar to chlorine.

Kronos has adapted the electrostatic technology to address these deficiencies. The unit uses high voltage applied across paired electrical grids to create an ion exchange that moves and purifies air. The stream of ions between the electrical grids gathers up particulate matter and deposits on the negatively-charged side.

Studies have shown that the system more effective than standard HEPA filtration in removing particulate matter - and has the additional benefit of clearing 95 per cent of hazardous gases in one air pass - but uses just one-third of the energy, according to Kronos.

Meanwhile, compared to currently available electrostatic precipitators, which deliver very limited air movement, Kronos delivers a high level of air without a fan, which reduces noise, and does away with the problem of ozone production.

"This technology offers features that are clearly superior to those presently available from other manufacturers," according to analysts at JM Ditton in a research note on Kronos.

They note that at present, the company is in the process of developing a consumer version of the technology along with partner company HoMedics, but has also designed systems for use on naval warships and plans to develop products for industrial applications, including laboratories and cleanrooms.

Recent market research published by McIlvaine has estimated that world cleanroom equipment sales will reach a new high of $4.4 billion in 2004, a rise of nearly 16 per cent over the estimated $3.8 billion achieved in 2003, and could be a $6 billion sector in 2007.