Airdog models typically operate quietly, especially in lower speed or sleep modes — often perceived as quieter than many traditional purifiers. In some harsh environments, it operates automatically in powerful mode to purify the contaminated air, which may be louder at high fan speeds, depending on the size and environment.  

The replacement frequency depends on where it is used. Whether you have pets or cook a lot affects the usage lifespan of your catalyst filter. It usually varies from 6 to 24 months. But we also have customers who always keep their original catalyst filter.

The catalyst filter may need to be replaced if it develops an odor. When it collects an odor, you can remove the filter and put it under direct sunlight to dry out the moisture. The evaporation process can help to remove the odor. If drying doesn't help eliminate the smell, it's time to replace the catalyst filter. You can order it through airdogusa.com. Make sure to select the correct model (X3, X5, or X8).

You could wipe it with a damp sponge. Please follow the cleaning tutorial video on this video: https://youtu.be/bXi3qHdLolY  for further guidance.