In-situ testing of portable air cleaners.

Portable air cleaners are commonly used to reduce the concentrations of particulate matter (PM) and other airborne pollutants in indoor environments. This project evaluates the in-situ performance of three portable air cleaners in residential sites, classrooms, and office environments using low-cost sensors.

Status: Current

Research themes: Health and comfort

Research areas: Cognitive and physical health in the built environment; Solutions for air leakage, ventilation and filtration; Indoor particulate and gaseous pollutant dynamics; Sensors and IoT Technologies for energy and IEQ

Project Objective

To develop an in-situ test methodology for portable air cleaners using low-cost sensors and understand the performance variations of these air cleaners in real-world environments. 

Approach

Portable air cleaners are tested switching between air cleaner and placebo operating conditions for two weeks. Three types of portable air cleaners ranging from low to high cleaner air delivery rate (CADR) are tested in two residential sites, two classrooms and one office environment in Toronto. Measurements are primarily made using low-cost sensors and their performance are compared against a more robust instrument. The effectiveness of portable air cleaners in reducing PM2.5 concentration are assessed by considering factors like operating parameters (e.g., interval, operating speed), test methodology (e.g., initial data truncation, experiment duration) and mixing of the environment.  

Findings

The results indicate that the effectiveness of portable air cleaners is not static but varies significantly within the same and different test environments due to the variation of room size, CADR, sources, and background loss rates of PM2.5. Certain low-cost sensor shows similar performance when compared to a more robust instrument, while another type of low-cost sensor is less responsive during elevated PM2.5 concentration.