After settling down at home to watch the 11 p.m. news, mechanical engineer David Andiorio was horrified to see live coverage of a fire at the Camp Hill, PA-based YMCA recreation center where he recently oversaw an hvac retrofit.

Andiorio, a performance assurance engineer at the Mechanicsburg, PA branch of the Buffalo Grove, IL-based Siemens Building Technologies, Inc., voluntarily dashed to the scene figuring that West Shore YMCA's maintenance director, Allan Allison and fire department officials might need his help manually operating the site's Siemens building automation system (bas).

It wasn't long after fireman extinguished the locker room fire allegedly caused by a faulty sauna's spontaneous combustion, that Andiorio's assistance was needed to clear dense smoke from the 65,000-sq-ft facility so damage inspections could proceed and the area could be secured until morning. The building automation control's 72-hour back-up memory power feature and interface link to all hvac equipment allowed Andiorio to operate vital hvac and lighting functions when building power outages temporarily restricted operation.

"Before we exhausted (the smoke), we tried to inspect the natatorium, but the fire marshal couldn't see ahead more than a foot or two even with his flashlight," recalled Allison. "He had to keep a hand on my shoulder while he followed me through the pool area."

A fire in this YMCA's locker room caused $225,000 in damages and tested the integrity of the ventilation system.

Exhaust Fan Clears The Way

With an abundance of individual power outages, tripped breakers, and broken circuits hampering operations, Andiorio manually turned on the exhaust fan feature of the 10,000-sq-ft natatorium's rooftop dehumidifier/air conditioner/heater, a Dry-O-Tron RS-150 by Dectron Internationale (Roswell, GA).

Within 15 minutes, the 5,000 cfm fan, which is sized and operated in conjunction with the outdoor air damper actuator, completely evacuated smoke from the 10,000-sq-ft pool room as well as the ill-fated locker room where the fire caused $225,000 in damages. Besides the pool area, the Dry-O-Tron also pulled smoke from the entire building (once doors and hallways were opened) and saved tens of thousands of dollars in potential smoke damage to the remainder of the recreation center.

In effect, Andiorio's project, which was designed by former Siemens engineer Jason Richards, P.E., passed the ultimate smoke bomb test. Smoke bomb testing is sometimes intentionally administered in sick buildings to visually reveal ventilation problems.

It was Richards and Andiorio that specified the factory-installed exhaust fan in the custom-manufactured Dry-O-Tron, but its intended use was not for smoke clearing during accidental fires. Instead, the two-speed fan operates at full capacity during heavily attended swim meets when the introduction of several hundred bodies, each that emit its own humidity and carbon dioxide, taxes a ventilation system. During nighttime hours however, the fan and outdoor damper are programmed for low-speed operation to conserve energy and save the YMCA money.

Air Quality Design Wins Praise

The 1997 retrofit replaced an aging air conditioning/heating air handler that unsuccessfully attempted indoor air quality and humidity control through a single wall supply. Consequently, years of excess chlorine-laden air wafting throughout the facility had permeated and corroded holes through the 40-year-old natatorium's cinder block walls and concrete decking. Siemens' remedy, which was a design/build performance contract for hvac and lighting, included more than the dehumidifier installation. Instead of just a wall grille supply, Richards' design included 4-ft-round spiral ceiling-hung ductwork. Its circular pattern and many take-offs equally distribute the air and eliminate the many dead air spaces the former hvac suffered.

"The Dry-O-Tron did its job, but the real credit goes to the engineer's indoor air quality design," said Ralph Kittler, vice president of sales, Dectron Internationale. "The circumstance of the fire and smoke was unfortunate, but it did prove the integrity of the indoor swimming pool's ventilation system and the effect its normal everyday operation has on swimmers and spectators. The system introduces the appropriate amount of outside air for homogenous air quality throughout the space, but also has an exhaust fan to dilute chemical gas buildup."

Siemens' retrofit design has been an "amazing improvement," according to Allison, over the previous ventilation system, which was specified before commercial dehumidifiers came on the hvac scene in the early 1970s. ES