Michael Schaadt, AIA, LEED AP, PGAV Architects
Chad Foster, AIA, Johnson County Kansas Facilities Management Department
Lou Hartman, PE, LEED AP, Crime Lab Design
Designed by PGAV Architects and Crime Lab Design, the Johnson County Sheriff's Office Criminalistics Laboratory is a 62,500-square-foot forensics laboratory in Olathe, Kansas, offering accredited forensic analysis in nine divisions, each with a unique environment. The laboratory is designed to achieve LEED platinum certification under the NC 3.0 rating system.
State of the art, flexible forensic laboratory spaces were created by carefully benchmarking other facilities while identifying trends and forecasts in the field of forensic science. The Labs21 design process and EPC credits were used as strategies to enhance the design. To promote collaboration between the various divisions the building features a central daylit core housing open office, administration functions, conference rooms, and communal spaces, with laboratory spaces ringing the periphery.
Critical to meeting the goals of value and environmental stewardship was identifying the appropriate HVAC system for the challenging local climate. To maximize value, a hybrid air delivery approach was chosen. Both laboratory and office spaces are fed from the same air handling system; this reduces both first cost and energy consumption, along with simplifying maintenance and improving reliability. In addition, office occupants benefit from much higher levels of fresh air due to sharing the system with the laboratory spaces.
To realistically target LEED platinum, it was recognized that significant energy conservation measures must be employed. Innovative strategies ultimately resulted in a building that operates 48 percent more efficiently than a comparable "baseline" facility.
To address the high cost of constantly tempering incoming outside air, a 16-foot-diameter heat wheel with a 3 angstrom molecular sieve coating transfers the heat and moisture from the exhaust stream into the incoming outdoor air stream while safely ejecting potentially harmful chemicals and odors. When conditions warrant, return air from the office area is also introduced into the incoming airstream to further temper the incoming air. Electrostatic filters and an "aircuity" monitoring system are employed to safeguard air purity. Air-flows are reduced using a variable air volume system coupled with low face velocity fume hoods. Occupancy sensors are employed both in laboratory modules and at the fume hoods to ensure that airflow setbacks are used effectively.
Several different options for heating and cooling were investigated through extensive energy modeling. A ground source heat pump plant was identified as being the best balance between efficiency and return on initial investment. The plant consists of a 300-ton heat pump system with a ground source heat exchange well field composed of over 22 miles of piping. It is sized to not only serve the Sheriff's Crime Lab but also supplement the plant operations of the adjacent County Communications Center. The interconnection of the chilled water system between the two buildings permits an improvement of efficiency and an additional layer of plant redundancy in the Communications Center, while also providing the Sheriff's Crime Lab with increased reliability.
Additional energy conservation measures were used to push the envelope of efficiency. The lighting control system features occupancy sensors, step dimming fixtures, daylight harvesting, and scheduled sweeps. Where the requirements of forensic science dictated extremely high light levels, LED fixtures were used. A rooftop photovoltaic system capable of generating up to 18.2 kilowatts of power when proper conditions exist was installed, and the building envelope was carefully detailed to ensure high insulation values and low air leakage rates.
The effects of these measures are tracked by an extensive metering system. These meters will automatically place the central plant into the most sustainable operational mode, as well as provide information to the facility operators that will enable building performance optimization over the lifetime of the facility.
In addition to energy conservation features, the laboratory was constructed with an emphasis on regionally sourced materials that exhibited a high level of recycled content and low levels of VOC offgassing. Domestic water use was greatly reduced with low and zero flow fixtures and zero irrigation landscaping. The site is sustainably developed by managing the stormwater in a system of bioswales, raingardens, and a wetland detention basin, and by reserving space for a facility expansion on site.
The design and construction team used Revit-based BIM modeling to enhance building design, support energy modeling, eliminate construction waste, and ensure the environmental performance of one of the nation's most energy-efficient forensics laboratories.