Projector Lamp Life
Setting your projector for its low power mode drops the brightness by about 20%. We concur, however in our reviews we find that the range can vary from as little as a 10% drop (barely detectable) to 30%, depending on the projector. Projector’s low power mode has two major benefits. First, the longer life. The typical projector claiming 2000 hours in full power claims 3000 hours in low power mode. That can differ, however. There are models out there that claim no increase of life in low power, and in some rare cases - a few Mitsubishi projectors, for example, claim 5000 hours in low power mode. The bulb may explode if they are used beyond there rated life.
Manufacturers design the mounts to limit damage, but you will need to get the projector serviced if your lamp does explode. Today’s projectors have two brightness modes, many now follow low and full power independently and adjust their warnings per your handling. Most warranties provided by manufacturers, are 90 days or 500 hours. In couple of years, however several companies that offer third party extended warranties on projectors have been offering lamp warranties as well.
source: http://www.projectorreviews.com/projectorlamps/ProjectorLampLife/index.php
