This filter is extremely easy to replace. The option menu of the projector gives an up to date account of the usage time for the existing filter. By resetting the filter time when it has been cleaned or replaced, the air filter will continue to give an accurate indication of the hours used. The filter is to be replaced when it is damaged or soiled. The projector may display such messages as check the air flow or turn off the projector and it is at this time a complete cleaning or replacement should occur.