Hitachi PH Instruction Manual page 270

Air filter replacement procedure
Loosen the knob and remove the air filter cover.
1
Air filter cover
Knob
Remove the air filter, and place a new filter, making sure the
2
orientation is correct.
Air filter
(The red mark side is the
inside of the printer.)
(1) First insert the top of air filter.
Air filter
Air filter
Red Mark
(2) Place the bottom of air filter on the guide.
Air filter
Guide
● Maintenance 12-2