Effects of air relative humidity and ventilation rate on particle concentrations within a reduced-scale room
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
The Author(s) 2018. An improved understanding of particle movement in ventilated rooms would help reduce airborne disease transmission in healthcare facilities. More empirical data are needed on the movement of small particles in rooms to investigate effects of air relative humidity (RH) and air exchange rates. In this study, small particles were injected into a reduced-scale room, and the particulate mass (PM) concentrations were measured at 12 interior locations in the room as well as at the ventilation air exhaust. The particulates were certified 'plain surface' melamine (polymethylenemelamine) microspheres (1.51 g cm 3 density; 1.98 m diameter) with hydrophilic surfaces. Experiments were conducted using three conditions of ventilation rate (4, 6 and 8 air changes h 1 (ACH)) and two RH levels (35% and 70%). Increasing the ventilation rate did not significantly decrease PM concentrations in the interior room area, but significantly decreased exhaust air PM concentrations. RH did not affect room PM concentrations for any of the ventilation rates. RH did not affect exhaust air PM concentrations for the 4 ACH or 8 ACH ventilation rates, but the exhaust air PM concentrations were higher at low RH than at high RH for 6 ACH. Regardless of ventilation rate and RH, PM concentrations were uniform throughout the room interior (potentially occupied) zone.
