BACnet Interface Simplifies

Engineered Systems, March, 2001

Large DDC Fume Hood Installation

The design team for the new home of S.C. Johnson Commercial Markets, Inc. in Sturtevant, WI, faced a daunting challenge as it planned a 277,000-sq-ft, multiple-story facility for a worldwide headquarters that would bring together all the people associated with S.C. Johnson commercial products.

How could the team meet its system efficiency goals plus successfully mix an open-plan office environment for 540 employees with 47 product research laboratories that needed to be isolated for occupant safety and comfort? The solution included a BACnet interface and teaming with Johnson Controls, Inc. (Milwaukee) and Phoenix Controls Corporation (Newton, MA), a Metasys[R] Connectivity Partner.

MEETING THE DEMANDS

By installing one of the largest BACnet-based direct digital controlled (DDC) fume hood systems in North America, the design team was able to meet its multi-use and efficiency goals, cost-effectively maintaining separation between the systems used in the facility's open and closed spaces.

A Metasys-compatible Celeris[R] laboratory airflow control system from Phoenix Controls easily connects with the facility's Metasys building automation control system (BAS) from Johnson Controls for a high-performance, yet easy-to-use, solution.

The installation, which involves the integration of approximately 100 variable air volume (VAV) fume hoods (rather than conventional constant volume hoods), includes a BACnet System Integrator. It also offers remote diagnostics, comprehensive reporting and trending through the BAS, and the ability to monitor, control and exchange data at high speeds from a central location.

According to project team members, the building's overall hvac design had to keep the laboratories negatively pressurized and ensure the safe and fast exhaust of hazardous particulates and bothersome odors. The work areas in these laboratories are proving grounds for the latest commercial waxes, solvents and aerosols, and are used to develop products for the commercial cleaning market.

The project team wanted to achieve maximum occupant safety and comfort, including optimum indoor air quality. As a result, it decided to keep the above-ground labs on a separate system, with a 140,000-cubic-ft/min, 100% outdoor air single-pass unit to keep odors from bleeding or back flowing into the rest of the building. Meanwhile, the air-handling function for basement-level laboratories as well as kitchen hood exhaust for the cafeteria

-- also on the basement level -- are each on separate systems.

GOOD TEAM = MAJOR SAVINGS

Phoenix Controls was selected as the airflow control products supplier, team members note, because of its field-proven record for critical room environment products that deliver precision, speed, and reliability. Seamless BAS integration was easily achieved because Phoenix Controls products are Metasys-compatible. The Metasys BACnet System Integrator is an enhancement, the team notes, because it simplifies the building's network, providing two-way, high-speed distributed and safe control.

Because the fume hood system is tied into the Metasys BAS, facility maintenance staff as well as the security team can monitor hood sash positioning. As a result, the VAV system runs at an optimum level because lab personnel can be reminded to keep hoods closed when they aren't in use, or the security staff can dose open hoods during routine checks by observing from a central control station which units are opened.

"That could amount to approximately $4,000 in energy savings per hood annually," estimates Jim Erickson, director of facility management for SC Johnson Professional.

From the project's onset, the planning and integration of the multiple control systems into one seamless network went smoothly, Erickson adds, because of the teamwork and collaboration between the Connectivity Partners, contractors, design engineers, and his staff. The headquarters was completed in 1997.

"Everyone was a winner on this project," Erickson emphasizes.