If you are staying at a hotel in Japan, you may come across a machine like the one pictured above and you may wonder what this device could be. The machine looks as if it could be for air conditioning or a heater. It can’t be a fan since there is no propeller to be seen. Looking at it closely, this appliance has several buttons. You may find it tuned off initially as you walk into your accommodation room. So, what exactly is it? It’s an air purifier – a common household appliance in Japanese homes and hotels. It quietly keeps the air clean by filtering out dust, allergens, and other pollutants. Let’s look at the functions on the device and see what each one is for.