Impact of impinging jet ventilation on thermal comfort and indoor air quality in office buildings

Abstract

This paper is dedicated to research of impinging jet (IJV) air distribution method. This system provides the desired indoor climate in office buildings. This paper describes the experimental requirements and boundary conditions for the CFD simulation and experiment in the climate chamber. The necessary modelling scenarios were developed to review the operation of the ventilation system according to different climatic conditions (winter, summer), human positions in the room and the shape of the supply duct. It is concluded that the shape of the air opening has little effect on the contaminant and heat removal effectiveness, 114%–122% and 1.12–1.16 respectively. At the same time, there is a large impact on the air exchange effectiveness (0.74–0.91). It was experimentally noted that in terms of contaminant removal and air exchange effectiveness, the circular opening provides better results. The human position depends on the supply temperature and flow velocity. By analyzing different scenarios, it was determined that the minimum acceptable distance to maintain thermal comfort within the standard requirements from the supply outlet is 1.7 m. As the distance from the air opening increases, the vertical air temperature difference at the height of 0.1–1.1 m decreases more than 2 times – from 1.9 K/m to 0.7 K/m. It is concluded that impinging jet ventilation has a great potential for use in office spaces both in winter and summer scenarios. This system significantly improves thermal comfort and indoor air quality. Applying impinging jet ventilation (IJV), limitations and peculiarities of the system such as supply air velocity, temperature and shape of the air duct must be carefully evaluated.