Performance comparison of air distribution systems for lecture room ventilation and their influence on vertical temperature gradients

Asit Mishra, Natalia Lastovets, Simo Kilpeläinen, Risto Kosonen, Markku Virtanen

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

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High occupant density, intermittent occupancy patterns, and the impact of classroom environment on teaching and learning, make energy efficient classroom air distribution a challenging task. Performance data of different classroom air distribution systems, during their service life, remains
scarce. The current study was hence undertaken to examine performance of three different, demand controlled, air distribution systems, in three in-use lecture rooms: mixed, thermal displacement, and a 50:50 combination of the mixing and displacement schemes. Air temperature and humidity were
measured at 20 different heights, at two different locations, in all three rooms. Occupancy was recorded during each scheduled lecture. The vertical temperature gradients varied with air-distribution system type and actual occupancy. Stratification magnitude was remarkably more for the
displacement system, compared to the other two. For displacement ventilation temperature stratification was primarily limited closer to the floor. Temperature stratification progressively increased through a class hour, gradually returning towards the initial state once students leave. In the occupied zone, temperature gradients stayed within ~4 °C, thus allaying concerns of local discomfort
due to temperature stratification.
Original languageEnglish
Title of host publicationProceedings of Roomvent & Ventilation 2018, 2-5th of June 2018, Espoo, Finland
EditorsRisto Kosonen, Mervi Ahola, Jarkko Narvanne
ISBN (Electronic)978-952-5236-48-4
Publication statusPublished - 5 Jun 2018
MoE publication typeA4 Article in a conference publication
EventRoomvent & Ventilation
- Espoo, Finland
Duration: 2 Jun 20185 Jun 2018


ConferenceRoomvent & Ventilation


  • classrooms
  • temperature stratification
  • local discomfort
  • ventilation


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