After successfully implementing sustainable and green engineering solutions for one of its client’s childcare centers, Roll International contracted P2S to perform an energy saving study on its 11-story, 220,000 square-foot corporate headquarters building in downtown Los Angeles and then design and manage construction of many of the recommended energy saving measures from the study.
The challenge was to determine which energy conservation would be the most economical to implement and provide the greatest return. Field investigation was required to determine potential energy conservation measures. P2S engineers had to perform calculations to determine potential annual energy savings, the cost of implementation and which measures we would recommend for implementation.
The following is a list of energy conservation measures that were included in the project:
- Replace two 270-ton centrifugal chillers with new high efficiency centrifugal chillers with variable speed compressors that have magnetic bearings
- Modify existing variable pitch vane-axial supply and return fans with fixed pitch blades and variable speed drives and new high-efficiency motors— two supply fans at 125 horsepower (hp) and two return fans at 60 horsepower
- Retrofit the two 15 hp chilled water pumps and the two 10 hp cooling tower fans with variable speed drives and high-efficiency motors
- Replace the existing pneumatic actuated return, relief and outside air dampers with new DDC actuated dampers
- Replace the existing pneumatic VAV box actuators, the reheat valve actuators and the room thermostats with new DDC actuators and thermostats
- Provide a new DDC control system to replace the existing outdated pneumatic controls
Provide CO2 sensors to provide demand-controlled ventilation for the outside air damper minimum position
This project involved an expedited schedule where P2S teams completed essential work in compressed timeframes. For example, P2S completed additional site verification in two weeks and schematic design in four weeks. P2S provided preliminary cost estimates a week later and final design in less than four weeks for rapid bid submittal.
The project is under construction as of this writing (July 2010). Even more, P2S was able to help the owner take advantage of Los Angeles Department of Water and Power rebates of $135,000 which helped offset construction costs.
Construction requirements call for the contractor to work after hours and on weekends so tenants would not be disturbed during construction.