RTD Commuter Rail Maintenance Facility Boasts First LEED Gold Certification in the Nation
Over 30% Energy Savings Despite Heavy Energy Demands
Traditionally, large industrial maintenance spaces are known to be energy inefficient with high demands to reach optimal occupant comfort while providing a safe environment. The team of MKK Consulting Engineers, together with Gannett Flemming, PCL Construction, and Heating and Plumbing Engineers, engaged multiple engineering techniques to achieve LEED Gold Certification, the first of any commuter rail maintenance facility in the nation.
The facility, which services the northern extension of the rail line, serves an initial fleet of 50 EMU cars, with provisions for future expansion to 80 cars. These commuter rail cars are serviced, inspected and maintained at the CRMF with a systems operations facility and operations control center located on the second floor of the building.
To optimize building comfort, the primary shop uses direct/indirect evaporative cooling with heat recovery. The cooled air is introduced into the main shop area and then transferred to the adjacent areas, allowing two spaces to be cooled with a single air stream. Additionally, the large shop space is provided with in-floor radiant heating which provides heat to the occupants where they need it the most. MKK’s use of variable refrigerant flow (VRF) systems throughout the office areas provides energy exchange in these spaces including heat extraction from the data center.
To even further maximize on energy recovery, MKK used air compressor waste heat to supplement the VRF system during winter months. In order to maximize the heating hot water system, a “series cascading” flow condensing boiler piping concept was applied. In this piping approach, return water from high temperature uses (domestic hot water, etc…) is designed to heat low temperature uses such as radiant floor. This “series cascading” system allowed for maximum boiler efficiency while reducing pump and pipe size.
Overall, despite the complexity in design, this system was constructed to allow for easy-to-use operation while exceeding the client’s expectations, and maintaining the budget and schedule. The overall building achieved a stunning energy savings of 32.3% over the ASHRAE 90.1 baseline and obtained LEED Gold certification.