Project Title:

UFAD Technology Transfer Program

Providing resources, training, and support for architects, engineers, and facility managers.

Status (updated 2/4/2008): Ongoing

Funding sources: CBE Industry Consortium

Project Objective

This project has two major objectives: (1) to develop and maintain the first website devoted to providing an unbiased source of knowledge on underfloor air distribution (UFAD) and related technologies; and (2) to provide technology transfer on UFAD design to CBE members and the building industry.

Significance to Industry

CBE has learned from field studies and industry feedback that incorrect design, specification and/or construction of UFAD plenums may be contributing to poorly performing buildings. Such projects do not realize the full benefits possible with UFAD systems, and slow wider adoption of the technology. Industry practitioners require specialized knowledge to avoid potential problems related to thermal decay, leakage, and thermal comfort.

CBE has made significant progress with its UFAD research, however a strong industry demand remains for the dissemination of these findings through multiple channels. This technology transfer program was developed to address these information needs by providing an unbiased description of UFAD technology.

Research Approach

This project supports the continuous maintenance of CBE's Underfloor Air Technology website, and efforts by CBE researchers to respond to the large number of requests for information on UFAD from CBE industry partners and the building industry at large.

CBE's UFAD technology website went live on the Internet in the fall of 2000, with the URL The content of the website is organized into five main categories including fundamentals, design guidelines, case studies, and UFAD events. Future activities include the posting of new CBE reports on: (1) indoor air quality, and (2) a cost analysis of UFAD systems. We will continue to post new material to the site on an ongoing basis, including case studies, design guidelines, and new research reports.

CBE's numerous articles on UFAD systems in the ASHRAE Journal, ASHRAE Transactions, and other publications have drawn many web users to the site. This underfloor website continues to provide a useful source of information for the building industry at large.

CBE staff also respond to regular inquiries from members of the building industry regarding correct design and operation of UFAD systems, UFAD benefits, and barriers to implementation. In addition, CBE staff provide regular UFAD training seminars and lectures at numerous industry events for engineers, architects, and facility management professionals.

2012 Symposium
In April 2012, CBE hosted a half day workshop on UFAD. As the adoption of underfloor air distribution (UFAD) has grown, a strong desire for design guidance and tools has emerged among industry professionals. CBEs extensive UFAD research spanning more than ten years has led to the recognition of CBE as the leading research institution on UFAD technology.

Download the presentations:
1. Introduction and Overview

2. Underfloor Plenum Design Guidelines. Fred Bauman, CBE

3. Design Sizing Considerations. Allan Daly, Taylor Engineering

4. Cooling Load Design Tool. Stefano Schiavon, CBE

5. Impact of Furniture on Peak Loads. Edwin Lee, Oklahoma State University

6. UFAD Case Studies. Tom Webster and Fred Bauman, CBE

7. Revised ASHRAE UFAD Design Guide. Fred Bauman, CBE

Publications and Reports

Bauman, F., T. Webster, and H. Jin, 2006. Design Guidelines for Underfloor Plenums. HPAC Engineering, July. (external link)

Webster, T., and F. Bauman, 2006. Design Guidelines for Stratification in Underfloor Air Distribution (UFAD) Systems. HPAC Engineering, July. (external link)

Click here for related publications>>


Bauman, F. 2005. Slide presentation from McCoy UFAD Workshop. Houston, TX, August 8. (PDF 3MB)

Bauman, F. 2005. Slide presentation from BetterBricks/ASHRAE Workshop. Seattle WA and Portland OR, September 7-8. (PDF 3MB)

CBE UFAD Website Homepage

CBE’s UFAD technology website has been on-line since 2000.

UFAD Seminar

Workshops on UFAD design led by CBE researchers are geared towards practicing industry professionals.

RAS Stratification Profile

CBE’s technology transfer program provides information on the unique characteristics of UFAD systems.