As predominantly indoor creatures, it’s important to maintain a healthy habitat for the hacker. [Kishan Pratap Singh] designed a clever solution in AirSense, an ESP32-powered air filter.If you’re thinking of cleaning the air in your environment, you might also want to know some properties about the air coming out of the filter. AirSense measures PM2.5 dust concentration, Air Quality Index (AQI), temperature, humidity, and atmospheric pressure. The various sensors are mounted along the exhaust path of the filter, which lets your know what kind of air it’s pumping out.The system drives a 150 mm exhaust fan mounted in a 3D printed cap that pulls air through a cylindrical Xiaomi HEPA filter inside a perforated metal trash can enclosure. The ESP32 and an LCD readout of the environmental data also live in the cap, giving the device a sleek look. While [Singh] chose to run the filter continuously, we wonder if it might be interesting to set it up to only filter the air if air quality drops below a certain level to conserve power, especially if you’re on a time-of-use power plan. That would require redesigning the sensor assembly (or running the unit in reverse), so maybe it’s over-complicating things?We’ve seen the Xiaomi Air purifier filter mentioned before, but under the auspices of hacking it’s filter DRM, an open source air filter designed by [Naomi Wu], and even an ESP32 pressed into service to plug an air purifier into Home Assistant.