RTD Denver's new commuter rail maintenance facility will feature maintenance areas top-lit by skylights. (Rendering courtesy RTD Denver)
Building new maintenance facilities for transit agencies are rarities, but when agencies do build them, it’s critical to design and build to the highest performance possible — these facilities and their efficiencies will live on for decades.
RELATED: 8 Ways to Make Your Transit Maintenance Facility More Efficient
As part of preserving limited revenue, agencies are focusing on how efficiently design facilities can help the bottom line.
1. Start with well-defined requirements. Successfully hitting the target involves defining it. Setting specific energy and water conservation targets — and using established metrics rating systems such as ASHRAE’s 90.1-2007 Standard or LEED’s Rating System for new construction — can help define what’s good, better and best performance versus minimally compliant. For example, the new commuter rail maintenance facility for RTD Denver targeted energy efficiency that is more than 32% more efficient than the reference baseline.
2. All together now. If the project delivery method allows — such as Design-Build or GC/CM — involve the entire owner, design and contractor team in concept design from day one. This will help test the constructability and budget feasibility of various building systems and design strategies.
3. Reducing lighting load.
Interior of Denver's rail maintenance bay.
These are 24x7x365 facilities. Daylighting, and in particular skylights, can significantly reduce the building’s lighting load and energy costs over the building’s lifetime. At the new commuter rail maintenance facility in Denver, maintenance areas are top-lit by scores of skylights that provide much of the ambient lighting. To supplement natural daylight, high-efficiently lighting such as LEDs or compact fluorescent should be used to reduce operational costs and the emissions associated with power generation.4. Heat and cool occupants, not the outdoors.
Radiant heating and cooling work best for large volumes such as shop areas and maintenance bays. Radiant heat slabs can be radiated to workers in shop areas without unnecessarily conditioning huge volumes of air found in high-bay maintenance facilities. Maintenance facilities often generate excess heat. Depending on the climate and other occupancies in the building, that excess heat can be captured using heat recovery ventilation units and moved to areas of the building.5. Look for free money.
Engage local utilities for potential incentives. Depending upon the amount of efficiencies, the incentives can be more than six figures! The key is to 1) engage the utilities early and 2) understand what incentives are available and how much upfront incentive payments can help offset the first costs of upgraded systems with higher performance. 6. Keep it cool.
Transit facilities cover a lot of ground, literally. Use concrete or other light surfaces with a high solar reflective index to help mitigate the heat island effect. Roofs should be a white or a light color with a Solar Reflectance Index (SRI) value of 78 or higher. Where hardscape paving is not required by operational needs, consider using native or adapted landscaping in lieu of turf to both reduce the heat island effect and reduce irrigation use. Selecting drought-tolerant plantings or plants that are either native or adapted to the region will reduce costs associated with irrigating with potable water. 7. Invest in local materials and businesses.
As public agencies that serve local communities and voters, consider using materials that are produced by local industries as appropriate to the building’s function and requirements. For example, if locally produced concrete block is available, that might be better than using steel wall panels from across the country. Procuring locally and regionally no only reduces the energy and emissions from transportation, but also returns money to the local businesses. Many agencies make supporting local small and disadvantaged businesses a priority. If these businesses also sell locally sourced and produced products, it’s a win-win for the community, for businesses and for the environment.8. Quality indoor environments for productivity.
Finally, high-quality indoor spaces with dedicated outdoor air supply (DOAS) that do not recirculate indoor air can help improve the health and productivity of employees. Careful selection of low-VOC paints and low-emitting finishes also help maintain a healthy environment. Since the impact of employee absenteeism is high, investment in these systems and low-emitting finishes can have a lasting positive impact.
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