The Coway Airmega AP1515G has a large square foot print so you can’’’’t miss it. It has an indicator for air quality, and prefilters and HEPA filters along two walls instead of one which ensures superior air cleaning. I found it to be very effective in lowering the AQI in a hall measuring roughly 600 sq feet. Larger areas may take longer but the Coway brand stands for reliable products. The SMART mode automatically adjusts the fan speed depending on air quality. A workhorse that delivers, and with the occasional deal available on e-commerce platforms, you wont feel like you emptied your wallet on it!