CBE's research team has developed a simplified, practical design procedure and associated software tool to determine cooling load requirements for underfloor air distribution (UFAD) systems. These are provided to improve the design and operation of UFAD buildings. Funding for this work was provided by CBE's Industry Partners, and by the California Energy Commission PIER Buildings Program.
For additional background on this project, see our project description page.
Use the Tool
There are two versions of the UFAD cooling load design tool available. The web-based version will be updated on an ongoing basis, while the Excel-based version will no longer be updated on a regular basis.
Online Cooling Design Tool
It was created for Firefox, Chrome, and Opera. Internet Explorer is not supported. Go to the online tool
We still provide the Excel-based version of the UFAD cooling load design tool. As of March 2011 it is up to date. However, in the future we will not update it. Use the link below to download the spreadsheet-based (Excel 2007) cooling load design tool:
Download the design tool (XLSM)
(Note: If you have trouble using the link above, use this link; after saving locally, change the filename by removing the word, "remove.")
This document describes how to load and run the Excel macros required for this tool, provides an overview of the spreadsheet elements, and an provides an explanation of the input and output values.
Download user notes (PDF)
Reports and Publications
Schiavon, S., F. Bauman, K.H. Lee, and T. Webster, 2010.
Development of a simplified cooling load design tool for underfloor
air distribution systems. Final Report to CEC PIER Program. CEC
Contract No. 500-06-049, July. A research report describing the algorithms and assumptions used in the design tool.
Schiavon, S., K.H. Lee, F. Bauman, T. Webster, 2010. Simplified calculation
method for design cooling loads in Underfloor Air Distribution (UFAD)
systems. Energy and Buildings 43 (2-3), 517-528. doi:10.1016/j.enbuild.2010.10.017.
Technical article on the fundamentals of UFAD cooling load calculations.
Schiavon, S., K.H. Lee, F. Bauman, and T. Webster, 2010. Influence of raised
floor on zone design cooling load in commercial buildings. Energy and Buildings, 42(8), 1182-1191. doi:10.1016/j.enbuild.2010.02.009. Technical article describing the influence of the raised floor on the thermal behavior of the building .
Bauman, F., T. Webster, and C. Benedek, 2007. Cooling Airflow Design Calculations for UFAD, ASHRAE Journal, pp. 36-44, October.
This paper refers to the previous version of the design tool.