Originally Posted by obonillaf
Case 1: John turns on his projector and uses it for 4 hours straight daily.
Case 2: Peter turns on his projector and uses it for just 30 minutes daily.
Any additional "damage" for Peter's projector than John's projector?
Peter will have less wear and tear on the projector since the fans aren't running as long and the internals aren't getting as much heat and use. I mean, that's pretty basic. You drive you car 30 miles a day in the city or 200 miles a day mostly on highways, you may get better gas mileage, but at the end of a year, you've put way more miles on that second car, and it will be worn out far earlier than the city driving car. But, it may wear out with more mileage on it than the city driving car will ever manage.
So, yeah, John will likely get more lamp life out of his projector. 4 hours a day - 365 days a year, that's about 1,500 hours a year, and call it a 3,000 hour lamp life, and it's lamp replacement time in 2 years. Still, a couple of lamp replacements and 6 years later it may be time for a new projector.
Peter only gets 2,000 hours on his lamp, but only puts 182.5 hours on it a year, so he's at 10 years before his first lamp replacement. But, at that 10 year mark, it may also be time to replace the projector.
All of this must be taken with a grain of salt though. Airflow, altitude, dust, and general build quality are just, if not more, impactful on the life of a projector and the projector lamp. A warmer room will have less internal cooling and may burn out not just the lamp, but the electronics earlier. A bunch of dust clogging things up may do the same.
I saw my first projector lamp fail in about 1,400 hours on a 4,000 hour rated lamp. I replaced the lamp and the next lamp was run for over 3,000 hours and still looked great. Change in setup or usage? None!
So, the first lamp sucked, the second one was better. No rhyme, no reason.