Los Angeles-based RNL Design’s National Renewable Energy Lab bears a certain sex appeal, if not because it demonstrates in its design its very purpose.

The LEED Platinum-certified building in Golden, Colorado, houses 800 NREL employees, who are part of the US Department of Energy, in a simple yet compelling 222,000-square-foot edifice. It is, therefore, be one of the country’s largest buildings to implement examples of what we might call Green Three: passivity, Net Zero Energy consumption, and living buildings.

Photos Courtesy of RNL Design

Its composition is of two narrow buildings interjected with a third wing, and all were oriented to capture sunlight for natural daylighting. It is a bit ludicrous to me in this new wave of green building that site orientation is considered so significant; it is, in fact, an ancient practice used the world over, yet one the West is just revisiting. Instead, the RNL design complements these proven sustainable building practices with what is indeed nouveau technology, e.g., transpired solar air collector technology.

While countries around the world still believe insulation is too high-tech to implement into residential or commercial construction, the NREL is incorporating its own methodology, which truly is high technology.

“The solar collector is… the way we get free pre-heated warmed air,” said Philip Macey, RSF project manager for Haselden Construction.

Solar energy hitting the large perforated metal plate on the south side of the building is transferred to the air flowing through it, pre-heating air entering the building, and thereby reducing the need for additional heating energy. A fan draws warmed ventilation air into the building through the plate.

“This process can efficiently preheat the air going into a building like the RSF by as much as 40 degrees F,” according to the NREL’s web site.

“These collectors can get 75 to 80 percent of the energy of the sunlight striking the collector absorbed into the ventilation air,” said Chuck Kutscher, principal engineer and group manager of NREL’s Thermal Systems Group. “We did a wide breadth of research, we covered a lot of different areas, and it was a much more comprehensive study of the technology than we would typically do. It was a totally new concept and we had to develop new equations to understand how it would work. Yet it is a simple and elegant technology that is inexpensive and highly efficient.”

Here are a few other design, building, and use practices that earned the building a 2011 AIA COTE Top Ten Green Projects award.

• Smart lighting and heating: Sensors determine when the windows should be adjusted for optimum HVAC controls. They then send a message to employees in the respective part of the building to change the operable windows accordingly.

• Daylighting: The totality of the workstations are daylit.
• Triple glazed, sun-shaded operable windows: Window shading was designed in accordance to location around the building, as, obviously, light doesn’t hit the entire building uniformly. (The very existence of operable windows in this element particularly thrills me, if not for its retro aesthetics and delivery of autonomy to building users.)
• Recycled materials: The building was constructed of reclaimed and recycled materials.
• Thermal storage: A labyrinth of massive concrete structures in the crawl space stores thermal energy and provides additional capacity for passive heating. It captures and stores the heat from the sun and cool air from the night until it’s needed. Then the thermal energy is slowly released for heating or air conditioning. This labyrinth also stores heat collected from the building’s data center, using it to heat the building when necessary. “Pulling outside air through the labyrinth can warm it five to ten degrees before it is further heated to warm the building,” according to the NREL web site.

The firm worked with Centennial, Colorado-based Haselden Construction to incorporate precast concrete insulated panels, almost 42 miles of piping for radiant heating and cooling, underfloor ventilation, an energy-efficient data center and workstations, and an on-site solar energy system into the plan. The thorough consideration of sustainable and green methods from design to construction to use means the building uses only one third to one half the energy used in similarly-sized office buildings, the NREL estimates. The building generates as much power as it uses, hence establishing what Popular Science called a “green tech incubation lab.”

Read more about the project.