A Novel Air Distribution Method - Principles of Air Curtain Ventilation

Abstract

The air distribution characteristics formed by an "air curtain" ventilation approach are investigated in detail. The airflow visualization and full-scale experimental results of air distribution in an occupied zone are reported in this paper. The Coanda effect of air curtain ventilation and the spreading airflow over the floor in a room are demonstrated. Additionally, the "air lake" or "air pool" phenomenon created by air curtain ventilation resembles displaced air movement to some extent. An air curtain ventilation approach is regarded as a bridge between mixing flow and displacement flow. In fact, it is a hybrid method of mixing flow and displacement flow. The current experimental study and its results are helpful in understanding a new air distribution method i.e. an "air curtain" used for room ventilation.

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

“…As a solution, the concept of vertical wall attached ventilation (WAV) was presented (Zhang, 2005;Li et al, 2008;Nielsen et al, 2010c), which is based on the combination of MV, DV and impinging jet flow. The concept was named air curtain (jet) ventilation (ACV) later (Li et al, 2012a;Li et al, 2012b;Yin and Li, 2012). A mixture of FA and RA is first delivered and attaches to the vertical wall then directs the jet downwards.…”

Experimental Investigation of Air Distribution in the Occupied Zones of an Air Curtain Ventilated Enclosure

“…For higher cooling capacities, the supply airflow rate must be considerably increased but this directed supply of cold air with larger speed to the occupied zone may cause local thermal discomfort, and may turn the stratified flow into mixing ventilation (Novoselac et al, 2002). To overcome this problem, a new method of air distribution known as Air Curtain ventilation (ACV) has been developed (Li et al, 2012). The concept of AVC has been developed in this study.…”

“…The concept of AVC has been developed in this study. This method is based on the principle of the Coanda effect (Coanda 1936(Coanda , 1967Reba 1966) and impinging jet phenomena (Li et al, 2012;Tu, 1995;Karimipana, 1996). The Coanda effect is a natural phenomenon in which a jet flow attaches itself to a nearby surface and remains attached even when the surface curves away from the initial jet direction (Boscoianu, 2010).…”

Experimental study on airflow characteristics of a square column attached ventilation mode

“…Furthermore, Li et al [28,29] and Yin et al [30] introduced the Air Curtain Ventilation (ACV) system based on the vertical wall attached theory. Cao et al also investigated an Attached Plane Jet (APJ), however their jet supply device was mounted on the ceiling, in such a way that the jet flow could attach to both the ceiling and the vertical wall [31,32].…”