ASHRAE UFAD GUIDE

Abstract

<strong>Purpose of This Guide</strong> <br>Underfloor air distribution (UFAD) is a method of delivering air to building spaces for the purpose of conditioning the space for occupant comfort. This type of air distribution may be appropriate for a number of different building types, including but not limited to schools, churches, offices, and libraries. Underfloor air distribution derives its name from the use of the area below a raised access floor (RAF) system as an air supply plenum to deliver conditioned air throughout the space to floor-mounted diffusers. This technology has traditionally been common in the computer-room industry; however, its use in commercial and institutional buildings is increasing in North America. <br>The purpose of this Guide is to provide assistance in the design, construction, and operation of UFAD systems. The Guide also incorporates important research results to support the UFAD design recommendations presented, and includes an extensive annotated bibliography for those seeking additional detailed information. This Guide does not cover alternate air distribution system design procedures in detail; however; reference to more common systems is used to explain or contrast the methods used to design UFAD systems. It is not the intent of this Guide to promote one system over another but to merely point out the major differences between UFAD and conventional system design. For more information on standard heating, ventilating, and air-conditioning design, please refer to other publications furnished by ASHRAE, including <em>ASHRAE Handbook (ASHRAE 2009, 2010d, 2011, 2012), Air-Conditioning Systems Design Manual (Grondzik 2007), and A Designer's Guide to Conventional Ceiling-Based Room Air Diffusion</em> (Rock and Zhu 2001). <br>The development of this Guide is based on a compilation of available information, including research results from laboratory and field experiments, simulation studies, manufacturers' literature, design experience of practicing engineers, and other relevant guidelines from users of the technology. Despite recent growth in the UFAD market, widespread experience with these systems is still at an early stage. The guidelines presented here are based on the most current and best available data and information. It is not the intent of the authors to cover every possible design scenario. It is up to the reader to use good engineering judgment and common sense when&#160;applying methodologies described herein. The Guide is intended for use by design engineers, architects, building owners, facility managers, equipment manufacturers, installers, utility engineers, researchers, and other users of UFAD technology.