How often does the air filter need to be replaced?

• You should replace the air filter when it becomes difficult to clean, when it is broken, or whenever you replace the lamp. One extra filter is included with the projector.
  
  In between replacements, you should clean the air filter after every 100 hours of use or whenever it becomes clogged with dust. Make sure you turn off the projector, wait for the cool-down period to end, and then disconnect the power cable before cleaning the filter.