Johnson County Crime Lab implements state-of-the-art fume hood technology

By Luke Savage, LEED Green Associate, Director of Ventilation Technology

On October 06, 2011 in Case Studies

The new Johnson County Sheriff’s Office Criminalistics Laboratory, KS, (JCCL) is designed to meet the Johnson County’s forensic service needs for the next fifteen years. Scheduled for completion in the first quarter of 2012, this new structure is located in Olathe, Kansas, and replaces the existing facilities that are currently unable to support the county’s goal of being a full service forensics science laboratory.

The new crime lab will be fully compliant with the accreditation criteria formulated by the American Society of Crime Laboratory Directors Laboratory Accreditation Board (ASCLD/LAB). This facility is equipped with the latest ventilation equipment to ensure the lowest possible ongoing operating cost and energy consumption while maintaining a safe working environment for lab technicians.

By implementing the latest in fume hood technology, JCCL will see an operating cost for this equipment at a mere 10% per hood of the operating cost of the hoods at their existing facility.

An average 6-foot fume hood operating at a 100 fpm face velocity, with the sash fully open, will consume 70,800 cubic feet of expensive tempered air every hour. The cost of this is approximately $8,260 per year. The design team for JCCL, PGAV Architects & Crime Lab Design, decided there was a better approach for the 19 chemical fume hoods required on this project.

Instead, JCCL will use Phoenix Controls Variable Air Volume (VAV) systems on the fume hoods to reduce these costs by cutting the demand for air as the fume hood sash closes.

The hoods selected for the project are Labconco’s Protector® XStream® Fume Hoods. These high performance fume hoods are capable of operating at a 40% reduction in energy consumption compared to its more traditional counterpart.

To tie both of these individually unique systems together, each chemical fume hood is equipped with the Labconco Intelli-Sash™ Automatic Sash Positioning System. The Intelli-Sash encourages the use of the sash as a physical barrier by automatically opening to a predetermined height that is below the operator’s breathing zone, acting much like an electronic sash stop.

Additionally, it will automatically close if a hood is unoccupied for a user-set duration, thus keeping other lab workers safe from unknown hazards. There is no operating cost benefit to a VAV system, unless the operator of the fume hood closes the sash, reducing the demand for tempered air.

By implementing the use of the Intelli-Sash, JCCL will ensure that the sash is closed when unoccupied, and encourage minimal sash openings when occupied, thus taking advantage of every possible opportunity to reduce the air volume demand.

The result of combining the Labconco Protector XStream, a VAV system, and the Intelli-sash is energy consumption and operating cost at 90% less than realized with traditional by-pass fume hoods.

In addition to the chemical fume hoods, JCCL will also be using Labconco Protector® XVS Ventilation Stations, a PCR enclosure, Glassware Washers, and Purifier® Logic Biological Safety Cabinets.