CASE STUDIES

Project: National Renewable Energy Laboratory's Research Support Facility

Design/Builder: Haselden Construction

Architect, Interior and Landscape Designer: RNL

Mechanical/Electrical/Plumbing Consultant: Stantec

CASE STUDY FEATURES:
Electrochromic Glazing
Thermochromic Glazing
Maximized Daylight
Natural Ventilation
Radiant Heating & Cooling
Shading Strategies

National Renewable Energy Laboratory's Research Support Facility

The National Renewable Energy Laboratory's Research Support Facility (RSF) in Golden, Colorado showcases sustainable, high-performance design as NREL's newest addition to its portfolio of energy efficient buildings. While functioning as an office space, the building doubles as a laboratory of technologies; allowing researchers to collect real-time performance data, measuring and tracking the building's energy use. The cost of construction amounted to $259/sf with the first phase opening in 2010 and the second phase opening in 2011. This 360,000 square foot facility houses approximately 1,300 occupants and its designed energy use was predicted at 35.1 kBtu/sf/year. After the first year of occupancy, the energy use measured of the 222,000 square foot RSF I was 35.4 kBtu/sf/year — 50% better than the ASHRAE 90.1 2004 Standard. This performance has generated numerous awards for the facility as well as a LEED Platinum rating.

Research Support Facility I and II.

The design/build team used a whole-building integrated design process so the Research Support Facility could serve as a model for cost-competitive, high-performance commercial buildings. The process encouraged innovation, reduced owner's risk, resulted in faster construction, controlled costs, optimized team member's expertise, and established measurable success criteria. The first design focus was on energy efficiency features, followed by renewable energy strategies. Extensive energy modeling was used to establish the basic structure and design of the building, with the energy performance requirements guiding its form and impacting its various functions.

Measured versus modeled energy consumption. Image courtesy of NREL.

The key design strategies included:

  • Optimal orientation and office space layout to maximize daylighting while minimizing unwanted heat gains and losses;
  • Fully daylit office wings with south-facing windows that reflect daylight to the ceiling and deep into the office space with light-reflecting devices;
  • Continuous insulation precast wall panels with thermal mass;
  • A labyrinth of thermal storage in the crawl space to provide passive heating and cooling;
  • Triple-glazed operable windows for high performance and natural ventilation;
  • Individual window sunshades to provide shade when needed;
  • Radiant heating and cooling;
  • Under-floor distributed ventilation;
  • Outdoor air preheating using transpired solar collectors before delivery to the thermal storage labyrinth and occupied spaces;
  • Plug load control strategies;
  • A data center that uses evaporative cooling, outside air ventilation, waste heat capture, and efficient servers; and
  • Roof top-and parking lot-based photovoltaics (2.5 MW).

The facility's windows are triple-glazed with improved thermal breaks to reduce heat loss and increase the energy efficiency of the window as well as the thermal comfort of the occupants. Individual overhangs maximize daylighting while minimizing glare and solar heat gain. Most windows are operable to allow occupants access to natural ventilation during mild weather. In addition, some windows can be automatically controlled and operated to support nighttime pre-cooling.

South-facing windows with shading projections surrounding the vision area. The daylighting area above the projections allows for light to enter deep into the spaces. Image courtesy of NREL.

The project also includes dynamic glazing technologies. The west elevation features electrochromic windows — windows that tint in response to a small electric current — which help to reduce heat gain in the afternoon hours. Thermochromic windows on the eastern balcony have tints that react to temperature change.

Various daylighting strategies were used to reduce the power consumption of the building considerably compared to ASHRAE 90.1-2007. Two long wings, with sixty foot depth, with an east-west orientation increase the natural daylight entering the building. The windows on these wings allow light to enter through the upper glass and then highly reflective louvers direct it toward the ceiling and deeper into the space — creating an indirect lighting effect. Light-colored reflective surfaces and low cubicle heights permit the penetration of light deep into workspaces. These daylighting strategies allow for fully daylit office spaces with no occupant more than thirty feet from a window.

NREL's Research Support Facility is a leading example of energy efficient technologies and architecture being used in unison to create a comfortable, sustainable built environment. While the location of this building allowed for optimum solar orientation that might not always be an option in other cases, many of the facility's design elements can be readily replicated. The permeation of this type of high-efficiency building design will impact energy demand among commercial buildings.

Comparison of baseline, installed, simulated, and actual power used. Image courtesy of NREL.

Sources:
"Net Zero Energy Building," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/51742.pdf

"Research Support Facility — A model of Super Efficiency," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/48943.pdf

"Session I: Energy Goals and Features of the RSF," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/session_i_energy_goals.pdf

"Session II: Performance-based Design-build Process," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/session_ii_performance.pdf

"Session IV: Occupant Behavior," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/session_iv_occupant_behavior.pdf

"Sustainable NREL," www.nrel.gov/sustainable_nrel/rsf.html

"The Road to Net Zero," U.S. DOE Energy Efficiency & Renewable Energy, www.nrel.gov/sustainable_nrel/pdfs/51124.pdf

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