S(pr)ay A Little, Mist A Lot



In early June, I attended my third National Fire Protection Association World Safety Conference and Exposition. This four-day event, held most recently in Las Vegas, has a special significance to me. Not only does it allow me to find out the latest in all aspects of fire protection [technology, codes, product innovations, etc.], it also serves as a reference point in my time as editor of PM Engineer. You see, it was at the 2006 NFPA event that I began my tenure as PME editor. And so this year I marked my second anniversary while walking the trade show floor and learning all about the latest and greatest trends in this important industry.

Like I did the previous two years, I visited countless manufacturer booths and got up to snuff on the newest products that engineers will soon be introduced to as they make their specifying decisions. In addition, I sat in on several seminars to find out about the key changes to NFPA standards 13, 25 and 72, and gain some insight into the latest Research Foundation test projects, such as the impact of ceiling fans and (separately) product deficiencies on sprinkler performance.

But unlike my first two shows, this year I saw an overwhelming presence of water mist systems, and they all drew my interest. Overall, I visited about 10 exhibitors to discuss their respective systems, but my favorite was one that was demonstrated every hour. Once this particular system was activated and spraying full-force, attendees were encouraged to walk below it to feel the fine water droplets for themselves - and to see how quickly they became dry after walking away from the spray [see photo]. This experience fascinated me, so I inquired why this happened.

I learned that these high-pressure systems produce thousands of droplets of water from the same unit of water required to produce a single droplet from a conventional sprinkler head. Then I was told that this large number of small water droplets has a vaporization rate of about 400:1 compared with a conventional sprinkler head.

Equally important, I became aware of NFPA 750, Standard on Water Mist Fire Protection Systems, and thumbed through it for the first time. Water mist systems have been around since the early ’90s, but their acceptance is slowly growing - especially for use in oil platforms and manufacturing environments. Not surprisingly, NFPA 750 has also expanded, with the current edition (2006) being nearly twice as long as that published 10 years before.

Armed with this basic awareness of water mist systems, I sought information from fire-protection engineers (who stopped by the PME booth) about their first-hand experiences with the systems. Most engineers had limited experience, but all expressed interest in reading more about them in a future issue of PME.

I wholeheartedly agree, so I welcome you to tell me about your experiences with water-mist systems as we research the topic for an upcoming article.

Remember: Your feedback (and mine) is powerful stuff. Like a single drop in a water-mist system, it can either get dispensed to thousands of fellow readers in the form of helpful and useful information - or it can evaporate quickly and be sorely missed.