A comparison between two underfloor air distribution (UFAD) design tools

Bin Chen, Stefano Schiavon, Fred S. Bauman, Qingyan Chen

Research output: Unpublished conference presentation (presented paper, abstract, poster)Conference presentation (not published in journal/proceeding/book)Academic researchpeer-review

1 Citation (Scopus)


The purpose of this study is to compare the capabilities and accuracy of two publicly available underfloor air distribution (UFAD) design tools (ASHRAE RP-1522 and CBE). The comparison is based on the air distribution models, diffuser types, ability to predict the design cooling load, supply plenum heat balance, temperature profile and setpoint, plenum configuration, and air distribution effectiveness. A combined database is fed into each tool's air distribution model to assess their accuracy. The results show the RP-1522 model predicts thermal stratification slightly more accurately than the CBE model in cases using swirl and square diffusers, but both results are comparably accurate for design purposes. The CBE UFAD tool has the key advantage of being able to predict the UFAD cooling load and model four different plenum configurations and both interior and perimeter zones. The RP-1522 tool is able to calculate the air distribution effectiveness.

Original languageEnglish
Number of pages8
Publication statusPublished - 2014
Event13th International Conference on Indoor Air Quality and Climate, Indoor Air 2014 - Hong Kong, Hong Kong
Duration: 7 Jul 201412 Jul 2014


Conference13th International Conference on Indoor Air Quality and Climate, Indoor Air 2014
Country/TerritoryHong Kong
CityHong Kong


  • Cooling load
  • Design tool
  • HVAC sizing
  • Underfloor air distribution (UFAD)

ASJC Scopus subject areas

  • Pollution
  • Building and Construction
  • Health, Toxicology and Mutagenesis
  • Computer Science Applications

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