Underfloor air distribution systems provide potential immediate and long-term cost savings for facility managers when compared to traditional overhead systems, including lower energy, remodeling, and installation costs, according to Troy, MI-based engineering firm Peter Basso Associates. These systems, which have been used for years in Europe, are gaining popularity in North America as their potential benefits are recognized.
Underfloor air distribution systems use the space below a raised access floor to transport supply air for space conditioning. This accessible underfloor area is also used to accommodate power and telecommunication cabling.
These systems offer potential cost savings over traditional overhead air distribution systems, including lower upfront costs for installation of wiring and cabling, energy savings related to the HVAC system, and lower reconfiguration costs. Other benefits are improved air quality, added flexibility for layout changes, heightened occupant comfort, faster installation, and a potential reduction in building height.
Dennis P. Sczomak, PE, LEED AP, vice president at Peter Basso Associates says, “People traditionally associate underfloor air distribution with computer rooms and data warehousing centers. However, these systems are increasingly being used in office buildings— a natural progression considering the amount of cabling infrastructure in today’s modern office environment. For many facility managers, underfloor air distribution systems are the optimal choice, especially if the facility has intense electrical and telecommunication needs or demands a flexible working space.”
Sczomak offers the following advice to facility managers who may be considering underfloor air distribution:
•Make a realistic assessment of the churn rate. With a major benefit being the adaptability to changes in layout, underfloor air distribution systems are optimal for office spaces with high churn rates. “Offices with the need for a flexible work space will most benefit from the easy access to equipment and power and telecommunications infrastructure that underfloor systems offer. A facility with these needs will achieve greater savings in terms of remodeling and reconfiguration costs. Those with infrequent layout changes will not reap these benefits to the same degree,” says Sczomak. Owners should assess their anticipated churn rate, evaluate the requirements for the space, and consider the first costs and the projected return rates when selecting an air distribution system.
•Evaluate and select the optimal system early on. The decision to use an underfloor air distribution system must be made very early in the design stages of a project because of the impact it has on other building features and functions. “An underfloor air distribution system affects all other building systems either directly or indirectly, including power, cabling, and architectural design. Changing from traditional to underfloor air distribution late in a project is tremendously difficult and necessitates significant redesign,” adds Sczomak. Further, this decision impacts building construction from a phasing standpoint and will impact how work is sequenced. Consequently, it is imperative that the air distribution system be established at the beginning of a project.
•Partner with designers experienced in underfloor air systems. While becoming more common, underfloor air distribution is relatively rare in the United States, and design standards are still evolving. Consequently, it’s important to work with a designer that has experience with these systems. Sczomak adds, “If designed or installed improperly, these systems lose their effectiveness and negate the benefits they are meant to achieve.”