California community center delivers uniform air comfort (with related video)
The $47 million Mitchell Park Library & Community Center recently opened to rave reviews for its indoor air quality (IAQ) and controllable air comfort. The center, which is part of the city of Palo Alto’s (Calif.) library system, opened in late 2014.
The 40,000-square-foot, award-winning library and its accompanying 16,000-square-foot community center rank first in air comfort among the city’s nearly 100 facilities. It also is one of California’s most sustainable facilities, says Debra Jacobs, P.E., LEED AP, PMP. She is project engineer for Palo Alto’s Public Works Department.
The Leadership in Energy and Environmental Design (LEED) Platinum-certified building has an underfloor air distribution (UFAD) system that allows occupants to position diffusers in a raised floor design. The system (displayed below on the left) enables directing air where it is most needed.
Supply air temperature differentials of as much as 4 degrees Fahrenheit are common in UFAD designs, however. This is especially true in buildings with window-dominated walls, such as Mitchell Park. Thus, Tunde Munz, P.E., LEED AP, principal at consulting engineering firm Guttmann & Blaevoet (G&B), San Francisco, specified UnderFloorSox manufactured by DuctSox, a fabric HVAC ductwork manufacturer. The manufacturer is based in Peosta, Iowa.
UnderFloorSox is designed for distributing airflow within UFAD plenums. Engineers can design the system to get the air dispersed within areas prone to temperature rise. The flexible 18-inch-diameter fabric duct uses laser-cut, linear vents that can be factory-engineered and modeled to address any perimeter thermal decay. The vents also safeguard against overcooling interior zones. The product can easily be reconfigured and routed around the myriad of cabling, piping, vertical floor supports and other concealed UFAD obstacles.
“As I walk through the building, the temperature is amazingly consistent, even when comparing the west and east portions of the building in the late afternoon’s setting sun,” Jacobs says.
In the video, learn about the energy efficiency of fabric ductwork.