A new heating and cooling system was installed at the University of British Columbia’s Centre for Interactive Research on Sustainability in Vancouver, adding to the building’s earth-friendly track record, officials say.

The four-story, 65,000-square-foot structure already uses green HVAC technologies such as geothermal, heat scavenging from neighboring buildings and the sun, earning the building Leadership in Environmental and Energy Design platinum certification.

The Vancouver office consulting engineering firm Stantec handled the HVAC design. It uses natural and displacement ventilation through underfloor air distribution. In this project, the system is an 18-inch-high ventilation system that distributes air strategically through floor diffusers. As a result, air is discharged from the floor upward, as opposed to overhead with conventional air-mixing ducts. The center’s supply air is discharged to each floor and is controlled with the building automation system by Honeywell.

Jimmy Ng led the Stantec HVAC design team that worked alongside professor and sustainability center project leader John Robinson, Ph.D., and architect firm Perkins & Will of Vancouver.

Although pressurized UFAD systems contributed to the achievement of several green HVAC credits, they sometimes suffer thermal degradation at the perimeter, leading to longer and inefficient mechanical equipment runtimes, Ng said. He chose to use DuctSox Corp.’s UnderFloorSox, which is a fabric ductwork designed and Underwriters Laboratories-approved for installation inside UFAD systems to distribute air closer to all floor diffusers and the perimeter. Ng worked with manufacturer’s representative Progressive Air Products to size the underfloor textile duct for minimal static pressure drops.

 Since air leakage in underfloor systems and its interior electrical junction boxes can add up to 30 percent efficiency losses when not sealed properly, general contractor Heatherbrae Builders of Richmond, British Columbia, pressure-tested the system for any leakage after construction.