- Client DC Public Schools/DC DGS
- Location Washington, DC
- Cost $10 M
- Size 183,000 sf
Global Engineering Solutions (GES) has been working hand-in-hand with DC Public Schools/DC DGS on the renovation of Johnson Middle School. Our work began as part of DCPS’ Phased Modernization program, which addresses the needs of neglected and out of date schools in three phases to bring them up to 21st century educational standards. The Phase 1 scope of work focuses on improvements to academic spaces (including improvements to lighting, technology and indoor air quality), corridors, bathrooms and the main entry way.
The GES team was awarded the Phase 1 contract for Johnson Middle School in November, 2009. The project required developing concept designs for all three phases of the renovation, and developing detailed construction documents for Phase 1. Prior to starting work, GES’ engineers conducted a detailed survey of the school to assess the current condition of the facility, and ensure the accuracy of the existing documents.
The survey uncovered numerous undocumented deficiencies which required significantly more resources than allocated by the Phase 1 program. These included a surge in water pressure in the hydronic system which was causing leaks throughout the building, the absence of a Direct Digital Control (DDC) system, and the need for a new HVAC system in the second and third floor classrooms.
The Phase 1 program was successfully completed in the summer of 2010. As money has become available, GES has been working with DCPS to correct the deficiencies noted in our initial assessment, focusing primarily on improving energy efficiency throughout the school.
The school is composed of four sections: A, B, C and D. Section A received a new HVAC system which involved removing all thru the wall unit ventilators and replacing them with new central AHUs with chilled and hot water coils. Conditioned air is delivered to spaces via medium pressure ductwork through VAV boxes with hot water reheat coils. Outside air is introduced to each AHU to provide of ventilation air as dictated by local codes. The main mechanical room is located in section A and feeds sections B, C and D through existing underground hot water piping. The design meets the sound level requirements per ASHRAE for classrooms, administration areas, auditorium and other building spaces.
The plumbing design largely consisted of new fixture installation and replacement of existing plumbing fixtures to meet LEED® Silver requirements.
The electrical power distribution system was modified to serve the new mechanical system, branch circuits for classroom receptacles, audio/visual and information technology equipment and new lighting systems. To meet additional LEED® requirements the lighting system and controls were designed based on ASHRAE/IESNA standard 90.1-2001 for energy conservation.
Based on a request from the DC Department of Education, DCPS required an energy model be prepared to compare the performance of the school prior to the summer 2010 renovation to the renovated configuration of the school. GES was tasked with developing this energy model and providing an energy assessment for Johnson MS.
GES developed a base line energy model that could be applied for the entire facility, but focused on the area of work that had been renovated. The baseline model was developed based on ASHRAE 90.1 and utilized room by room load calculations, modified as needed to depict real building values. The deliverable for this task was the development of an energy model report which included the calculations and a summary of the findings comparing the building’s performance.
GES also conducted an assessment of the current conditions at the school to determine energy usage and efficiency of the lighting and HVAC systems. From the owner, GES obtained PEPCO invoices to analyze historical electrical power usage. GES’ electrical and mechanical engineers created load calculations and then provided two rounds of Trane TRACE modeling for a 920 sf space. The model showed a first year savings of $834 per classroom or 53% savings over the baseline based on the provided energy costs.
Since the completion of the energy audit, GES has successfully undertaken and completed several additional projects at Johnson Middle School, including the installation of a Direct Digital Control System, and the renovation of two science laboratories.