P2S provided mechanical and plumbing design and construction support services for a new lab and office building at the County Sanitation District No. 20 of Los Angeles County's water reclamation plant in Palmdale, California. The lab and office building, which is being constructed as a part of a major plant upgrade project, consists of analytical laboratory with three (3) fume hoods, sample receiving room with two (2) fume hoods, deionized (DI) water room, garage, control room, lockers with showers, control room, lunch room, conference room, lobby and offices.
Project design had a very short timeframe. This required close coordination between the District's engineers and P2S. P2S worked closely with the District chemists and lab engineers to optimize fume hood design, develop specifications and review of chemicals and system needs. P2S was responsible for providing detailed mechanical and plumbing specifications, including energy conservation measures, for a number of systems and components including laboratory exhaust ductwork, lab exhaust fans, humidifiers, 100% outside air (OSA) package direct expansion A/C equipment, DI water equipment and piping, variable frequency drives, laboratory control system, direct digital control system, and sequence of operations for the lab and office HVAC systems.
To identify optimum systems for energy and resource savings, P2S performed load calculations for the entire building envelope. For the lab, P2S utilized a 100% OSA packaged rooftop gas/electric unit that includes digital scroll compressors that allow for tight capacity and temperature control. Also, it included a supply fan with VFD, hot gas bypass, multiple staging and an oversized condenser.
Also for the lab, P2S utilized pressure independent exhaust and supply air valves and a laboratory control system for variable air volume (VAV) control. This control system is designed to provide the correct amount of supply air, exhaust air, and pressure between rooms—based on the usage (opening and closing) of the fume hoods.
P2S fitted the fume hoods with sash sensors and monitors to provide additional VAV control and safety. For additional safety, the fume hood exhaust system has a redundant exhaust fan and dampers with automatic switchover should one fan fail.
For the offices, P2S utilized a similar packaged rooftop gas/electric unit that includes a supply fan with VFD for VAV operation and multiple staging and an oversized condenser. Independent exhaust systems were designed for the restrooms/locker rooms and lunchrooms. To reduce energy consumption, P2S designed the locker room to utilize as much make-up air from as many adjacent conditioned spaces as possible. And because of the significant use of outside air (OSA), and the dry climate of the Mojave Desert, both the lab and office systems include humidifiers.
P2S coordinated the new mechanical and plumbing systems design with the District's engineers—electrical, structural, and architectural. Our staff met with the engineers to coordinate electrical, structural and architectural issues.