NC2000 prism cleaning

[Muhamad Taufiq]

It is so sad to see the vast majority of installs extracting air from the projectors and then replacing the air with untreated air from outside.
I've done some maintenance in a few cinemas where the air was being recirculated in the booth - with an AC system in place of course - and the guts of the projectors were just spotless.

I'm sorry if I'm misunderstanding this, but aren't most (xenon) projectors required to have 450-600 cfm exhaust air? Unless it's a laser projector which typically doesn't need dedicated exhaust.

[Leo Enticknap]

The issue is intake air as distinct from exhaust air. If the air in the booth gets there through no or inadequate filtration, then contaminants in it will overwhelm the projector's intake air filters more quickly, the static pressure around them will build up, and then eventually the dirty air will find ways around those filters and into the projector in an unfiltered state, where it will contaminate the critical optical surfaces.

Mark, I recall that thread and you replaced the light engine, not just a prism. And a prism won't have any stuck pixels. right?

Could this be a terminology misunderstanding? NEC uses the term "prism assembly" as the equivalent of Barco's "light engine," meaning the complete chassis with formatters, DMDs, and the prism mounted on them.

Agreed completely with earlier comments about the ambient air quality being a major factor. I've noticed that projector intake air filters at sites in the LA metro and 'burbs get dirty a lot more quickly than the ones in more rural locations.

[Mark Gulbrandsen]

The dirtiest filters in my service area were at the theaters in Jackson, Wyoming. Especially in Winter when every one is burning their fireplaces... They used to buy filters two casers at a time for just 5 projectors.

[Mark Gulbrandsen]

I'm sorry if I'm misunderstanding this, but aren't most (xenon) projectors required to have 450-600 cfm exhaust air? Unless it's a laser projector which typically doesn't need dedicated exhaust.

Depends on the wattage of the lamp. The NEC internal lamp house blower does more than that by itself.