A review of advanced air distribution methods - theory, practice, limitations and solutions

Abstract

Ventilation and air distribution methods are important for indoor thermal environments and air quality. Effective distribution of airflow for indoor built environments with the aim of simultaneously offsetting thermal and ventilation loads in an energy efficient manner has been the research focus in the past several decades. Based on airflow characteristics, ventilation methods can be categorized as fully mixed or non-uniform. Non-uniform methods can be further divided into piston, stratified and task zone ventilation. In this paper, the theory, performance, practical applications, limitations and solutions pertaining to ventilation and air distribution methods are critically reviewed. Since many ventilation methods are buoyancy driving that confines their use for heating mode, some methods suitable for heating are discussed. Furthermore, measuring and evaluating methods for ventilation and air distribution are also discussed to give a comprehensive framework of the review.

Experimental comparison of local low velocity unit combined with radiant panel and diffuse ceiling ventilation systems

“…In the convective type of localized systems, personalized ventilation in conjunction with mixing ventilation or displacement ventilation would provide a higher thermal comfort and a better perceived air quality compared with that could be provided by the total volume system. 30 According to the EN ISO 7730:2005, 68 how the increased air movement could enhance thermal comfort, e.g. by using desk fans is prescribed.…”

Dilution-based Evaluation of Airborne Infection Risk - Thorough Expansion of Wells-Riley Model

“…The copyright holder for this this version posted October 6, 2020. ; https://doi.org/10.1101/2020.10.03.20206391 doi: medRxiv preprint is served with displacement ventilation that the conditioned air is supplied near the floor level (S1-S14) (with the supply air temperature around 20°C and supply airflow rate around ACH) and exhausted from the ceiling (E1-E3). Displacement ventilation has an airflow pattern with high contaminant removal efficiency at the breathing level [13]. SF6 (released from the mouth of the infector in Figure 1) is used as the tracer gas to represent the airborne contaminants [31][32][33].…”

Adaptive Wall-Based Attachment Ventilation: A Comparative Study on Its Effectiveness in Airborne Infection Isolation Rooms with Negative Pressure

“…There are many different air distribution modes for built environments [27] . The general principles for AIIRs are to achieve and maintain a directional air distribution from a clean area to a less clean area [28] , [29] and to position exhaust vents as close to contaminant sources as possible [12] .…”