Guidance on designing underfloor air distribution systems is covered in a new publication by the American Society of Heating and Refrigerating Engineers.
The author, Fred Bauman, P.E., says that underfloor systems were originally introduced in the 1950s in spaces having high heat loads such as computer rooms. However, he says, they have proven to be the most effective method for delivering conditioned air to localized diffusers in the occupied zone of a building.
Unlike the most common HVAC systems, which supply air from the ceiling, underfloor systems use the open space between a structural slab and the underside of a raised floor system to deliver conditioned air. Outlets are at or near floor level and can provide different levels of individual control.
In a 1999 study by the Building Owners and Managers Association and Urban Land Institute, building temperature figured prominently as an issue that bothered tenants and occupants.
The "Underfloor Air Distribution (UFAD) Design Guide is US $87, or US $69 to Ashrae members. Visit www.ashrae.org, or call 1-800-527-4723.