I live in an very polluted area (average PM2.5 level in winter around 300 µg/m³) and have been running the same filter non-stop in a cheapest Xiaomi purifier fo

I live in an very polluted area (average PM2.5 level in winter around 300 µg/m³) and have been running the same filter non-stop in a cheapest Xiaomi purifier for 1.5 years. It's almost black, but works fine, as confirmed by DIY PM sensors. I think it puts more strain on the motor, but I don't see any difference in efficiency.