During the Summer break, it is easy to forget about projector maintenance. After all, very few people are in the building and most units are not being used. However, it is during these quiet Summer months, LCD projectors are most vulnerable to damage.
With no movement in the classroom and air conditioning units turned off, dust will gather on the top and inside of the projector. Dust will continue to amass all Summer long. When the projectors are finally turned on in the Fall, the small internal cooling systems will instantly choke on the accumulated dust. Often, air filters are left quite dirty at the end of the semester. The additional dust collected through the Summer dormancy finds its way past the filter and directly in contact with sensitive mirrors and lenses. This results in a hazy, distorted image as well as brightness and color degradation. In many cases, this can also damage the cooling fan and lead to overheating and a shorter lamp life. 
Most manufacturers consider damage caused by dust to be a maintenance issue, which is not covered under their warranty programs. In cases like these, they will charge for cleaning and repair.
Step one: clean your filter. We cannot stress this enough. Get up there and clean it. When in doubt, clean it out. There is no such thing as cleaning your filter too often. Before you start up your projector for the first time of the semester and before you say goodbye to it for vacation, clean the filter. OK...I think you get the picture. Clean your filter.
Step two: bag it before you go. You can protect the projector from dust by sealing a plastic bag around the whole unit. There is no need to dismount the projector for this. Most trash bags will work perfectly; just use masking tape to seal the bag and hold it in place.
Step three: clean your filter.
We hope this helps. Let us know what you think!
-Luke B.
