ACHRNEWS

Hvac system gets real-world smoke test

June 1, 2000
CAMP HILL, PA — 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 YMCA recreation center here, where he recently oversaw an hvac retrofit.

Andiorio, a performance assurance engineer at the Mechanicsburg, PA branch of Siemens Building Technologies Inc., immediately 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 building automation system (bas).

It wasn’t long after the firemen extinguished the locker room fire — allegedly caused by a faulty sauna’s spontaneous combustion — that Andiorio’s assistance was needed. Could he help clear dense smoke from the 65,000-sq-ft facility, so that damage inspections could proceed and the area could be secured until morning?

As it turned out, the bas’ 72-hr back-up memory power and interface to hvac equipment meant that Andiorio could operate necessary hvac and lighting functions.

See what?

“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 YMCA’s Allison.

“He had to keep a hand on my shoulder while he followed me through the pool area.”

With an abundance of individual power outages, tripped breakers, and broken circuits hampering operations, Andiorio manually turned on the exhaust fan for the natatorium’s rooftop dehumidifier-air conditioner-heater, a Dry-O-Tron® RS-150 by Dectron, Inc.

Within 15 min, 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 swimming pool area, as well as the locker room, where the fire caused $225,000 in damage.

Moreover, once doors and hallways were opened, the system pulled smoke from the entire building, preventing smoke damage to the remainder of the center.

Before the fire

For years, chlorine-laden air had traveled throughout the facility, permeating and corroding holes through the 40-year-old natatorium’s cinder block walls and concrete decking.

An aging, outmoded air conditioning-heating air handler had attempted IAQ and humidity control through a single-wall supply.

Siemens offered a design-build performance contract for hvac and lighting, so the project went beyond a 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 system suffered.

According to Allison, the retrofit design has been a major improvement over the previous ventilation system, which was specified before commercial dehumidifiers came onto the hvac scene in the early 1970s.

The new rooftop unit worked out well, “but the real credit goes to the engineer’s indoor air quality design,” said Ralph Kittler, Dectron vice president.

“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 homogeneous air quality throughout the space,” he added, “but also has an exhaust fan to dilute chemical gas build-up.”