Building orientation and windows: Office bays are 60 feet
wide ( 18 meters) and oriented to
maximize daylight penetration.
Window-to-wall ratio to the south
is 24 percent and to the north 26
percent. The triple-glazed, argon-filled windows are shaded against
summer sun, and are opened (by
the occupants) when the building’s computer system signals
that it would be an efficient cooling tactic. Electrochromic tinted
windows on the west wall are
controlled by the staff and span
60 feet by 12 feet on three floors.
East-facing windows use a cheaper, fully automatic thermochrome
technology, darkening as the day
grows warmer.
DEPARTMENT OF ENERGY / NREL
Daylighting is aided by light louver window
treatments. They look like venetian blinds but
each slat is an optical light duct arranged to throw
sunlight onto the ceiling, deep in the office bay.
SE TH MASIA
DEPARTMENT OF ENERGY / NREL
landscaping features gabion
walls, using 1,000 cubic yards of
rock out of the foundation excavation, contained in baskets made
of recycled steel. Stormwater flows
off the roof to water the xeriscape
plantings. Smart, climate-sensitive
computers control additional irrigation, cutting water use about 30
percent. This wing-shaped tower
is an air intake for the labyrinth
thermal-storage system.
DEPAR TMEN T OF ENERG Y / NREL
(Above), the ground-level labyrinth thermal-storage system, shown here under construction, preconditions ventilation air. About 4.5-feet high
(1.5-meter high), with a volume of roughly 360,000 cubic feet ( 10,200 cubic meters), the concrete plenum draws outside air through intakes at the second-story level. The air gains or loses heat to the concrete thermal mass and reaches the underfloor HVAC system at about 50° F ( 10° C) in winter and 70° F ( 21°
C) in summer. The north-wing labyrinth works during the heating season, taking waste heat from the data center. The south-wing system handles both
heating and cooling loads, feeding preconditioned air to an evaporative cooler in summer. Steel frame is held aloft on surplus natural-gas piping, each column 33 feet ( 10 meters) long and partially filled with concrete. Concrete forms are filled with chunks of Denver’s old Stapleton Airport runways to reduce
the pour of fresh concrete. About 20 percent of all building materials are recycled materials, about 75 percent of that content diverted from landfills.
