Can I access the lamp and air filter with the ceiling mount installed?

• Yes. The projector's lamp cover is located on top of the projector, so you can replace the lamp when the projector is mounted to the ceiling (upside-down). See Replacing the Lamp.
  
  The air filter is located on the side of the projector and can be removed to clean both sides of the filter. See Cleaning and Replacing the Air Filter.