An air purifying system includes an air purifier mechanism, a controller, and a sensing device. The sensing device is configured to measure an air quality parameter of the air entering the housing via the air inlet to generate inlet air quality data, and to measure an air quality parameter of the purified air exiting the housing via the air outlet to generate outlet air quality data. The controller is configured to: receive the inlet air quality data and the outlet air quality data, compare the inlet air quality data and the outlet air quality data with their corresponding predetermined threshold ranges, and determine an action to be taken.