Thermal stratification in building interior zones with Under-Floor Air-Distribution systems

Kisup Lee, Guangqing Xue, Zheng Jiang, Qingyan Chen

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)

Abstract

Partially-mixed air-distribution systems such as Under-Floor Air Distribution (UFAD) systems supply directly conditioned air into an occupied zone. This study examined the influence of the design parameters such as diffuser type, diffuser number, supply air temperature at diffuser, and space type on the thermal stratification of the UFAD systems. Our investigation first used an environmental chamber to experimentally measure the air distributions in an office, a conference room, and a classroom with swirl diffusers, square diffusers, and linear diffusers. These experimental results were used to validate a CFD model that was further expanded to establish a database of 54 cases. The results showed that the diffuser type had a significant impact on the air temperature difference between the ankle and head level of a standing person in the occupied zone. The swirl diffuser created the largest thermal stratification, while the linear diffuser presented an almost uniform air temperature distribution in the occupied zone. However, the linear diffuser showed the highest averaged air temperature in the occupied zone, while the swirl diffuser maintained the lowest air temperature in that space. The air temperature difference between the ankle and head level increased when the supply air temperature at the diffuser was decreased or when the number of diffusers was increased.

Original languageEnglish
Title of host publication12th International Conference on Indoor Air Quality and Climate 2011
Pages1155-1161
Number of pages7
Publication statusPublished - 2011
Event12th International Conference on Indoor Air Quality and Climate 2011 - Austin, TX, United States
Duration: 5 Jun 201110 Jun 2011

Publication series

Name12th International Conference on Indoor Air Quality and Climate 2011
Volume2

Conference

Conference12th International Conference on Indoor Air Quality and Climate 2011
Country/TerritoryUnited States
CityAustin, TX
Period5/06/1110/06/11

Keywords

  • Airflow
  • Thermal gradient
  • Under-floor air distribution

ASJC Scopus subject areas

  • Pollution

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