EVENT CENTER: The multipurpose event center at Northeastern State University (NSU) in Tulsa, Oklahoma. VRV UNITS: Four variable refrigerant volume (VRV) systems at the NSU event center provide multi-zone air conditioning control and help save energy. BLENDING IN: Chilled beams and diffusers help provide low-key yet effective comfort at Amber Trails Community School. It’s impossible to take stock of the thousands of sustainability measures being incorporated into commercial buildings today — the market and technologies appear to have nothing but unlimited opportunities for growth ahead. But here is a look inside three recent projects that illustrate successful implementation of sustainable building solutions. The HVAC system at Northeastern State University’s (NSU’s) 78,200-square-foot multipurpose event center outside of Tulsa, Oklahoma, needed to satisfy the occasional high-occupancy requirements of an event and athletic center while providing daily back-of-house functionality. In addition to an auditorium/arena, the event center houses athletic offices, locker rooms, the NSU team store, concessions, and  a meeting space. When a traditional four-pipe system was deemed not econo...