Projector fans ensures that the machines keeps working at peak performance throughout its life span.  Beside ensuring a source of clean power, the second most important thing is ensuring clean and cool air flow. Projectors bulbs produce intense heat. Keeping it cool requires constant air flow

There are generally 3 different types of fan in a standard DLP, LCD or LCOS projector. A set cools the ballast,  an air intake fan for the chassis as well as an exhaust fan, and another for cooling the lamp. The chassis fan helps in sucking out hot air generated by the lamp. Some DLP and LCOS projectors also have fans near the lenses assembly to cool the DLP chip.

If any of these fans are defective, a projector may not power up at all. Where they are clogged with dust and soot, the projector will start to overheat. Overheating can result in unexpected shutdown, burnt lamp, and total failure of the projector.