Intermittent personalized ventilation coupled with mixing ventilation for occupant protection against active and passive contaminants and energy savings

Abstract

An intermittent personalized ventilation PVMmodule (PVMM) coupled with a conventional mixing ventilation system (MV) was studied to investigate its ability in protecting occupants from indoor contaminants. This study examines the intermittent PVM operating frequency range that minimizes active and passive contaminant concentration near the occupant and nearby surfaces. A 3D CFD model of a typical office space was developed for this study and validated through experiments done in a climatic chamber. Simulations were performed under different typical indoor frequencies (0.3 Hz, 0.5 Hz and 1 Hz) and a typical personalized ventilation average flow rate (7.5 L/s). The space was considered to be infected with CO2 and particles of diameter 1 µm. Results showed that under a frequency range of [0.78 Hz – 0.94 Hz], the intermittent PVM was able to provide good occupant protection with a satisfactory ventilation efficiency of around 77%, intake fraction range of [11.8 %, 26.8 %] and a deposition fraction range of [7.5 %, 8.75 %]. Moreover, the system was able to reduce energy costs by 16.1% compared to steady state personalized ventilator. © 2018, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.