Ashrae Journal - December 2008 - 37

sation problems. Ceiling coordination can be simplified with the use of pendant (indirect) lighting, with the beams recessed in the ceiling and running above the lights. The installation issue is eased by stringing beams together in an end-to-end arrangement. Typically, up to four or five active chilled beams can be connected this way with a single connection point for the primary air at one end. In rooms or areas with high cooling loads exceeding 10 W/ft2 (108 W/m2) (such as equipment rooms with as much as 20 W/ ft2 (215 W/m2) of heat-producing equipment), fan coil units can be substituted in place of the chilled beams in these specific areas. Concerns over condensation should be avoidable through proper building design and effective direct digital control of the water temperature entering the chilled beams.4 As previously indicated, the temperature of the water entering the chilled beams is normally maintained at 3°F (–16°C) higher than the dew-point temperature in the space. Summary plications, Chapter 14, Laboratories. 3. Bartholomew, P. 2004. “Makeup air heat recovery: saving energy in labs.” ASHRAE Journal 46(2):35–40. 4. Rumsey, P. and Weale, J. 2007. “Chilled beams in labs: eliminating reheat & saving energy on a budget.” ASHRAE Journal 49(1):18–25. Acknowledgments The software used to derive chilled beam performance, and the information on chilled beam characteristics described in this article, were provided by a chilled beams manufacturer. TM ® Steam and Hot Water “Flexible Tube” Boilers • Exclusive “Flexible Water Tube” design • Full non-prorated 25 Year Warranty protection against thermal shock • High efficiency performance • Simplified maintenance • 15 to 300 lbs. working pressure • 6 to 500 HP • Oil, Gas, Dual Fuel, Electric Contact us for complete information An HVAC design that uses active chilled beams in combination with an airhandling system having dual energy recovery can result in substantial reductions in the energy required for cooling, heating and fans. The size of the air-handling system, chillers, and boilers can also be greatly reduced. Compared to a traditional system, the first costs should be roughly the same. Although, if the floor-to-floor height of the building can be reduced due to smaller ductwork, a savings in first costs is possible. Chilled beams should also compare favorably to fan coil units in terms of physical space and maintenance requirements. Careful attention to the layout of the chilled beams and supplemental supply air devices (where required), can result in adequate or good air distribution, as well as ventilation effectiveness in the laboratory spaces, including those with fume hoods. References 1. USGBC. 2005. LEED Reference Package, Version 2.2. Washington, D.C.: U.S. Green Building Council. 2. 2007 ASHRAE Handbook— HVAC ApDecember 2008 Bryan Steam LLC — Leaders Since 1916 783 N. Chili Ave., Peru, Indiana 46970 U.S.A. Phone: 765-473-6651 • Internet: www.bryanboilers.com Fax: 765-473-3074 • E-mail: bryanboilers@iquest.net BRYAN BOILERS ® www.info.hotims.com/16020-10 ASHRAE Journal 37

Ashrae Journal - December 2008

Table of Contents for the Digital Edition of Ashrae Journal - December 2008