Axiom Home Page Forums General Discussion Technical Questions Do you use a UPS with your projector / HT system?

Not true John. When the bulb is lit, the fan is running to keep it cool. The fan is needed and whomever was in the discussion before that came to the conclusion you reference above was also wrong.

Mdrew is right. Its a sure fire way to not only shorten life of an expensive lamp, but possibly damage internal components in the projector from overheating. Spikes from power outages are another problem though thats solved with a surge suppressor.

Hi all:

Thanks for the great discussion. I suppose I could get a small UPS (which would have some surge protection) for the projector, and then a standard surge protector for the rest.

Alternatively I could just plug everything into a simple power strip and use the savings to buy better cables - that's bound to help enhance my A/V experience....

Yeah, I gotta agree with Mike and John here, John. If projector lamps didn't need to be actively cooled when turned off, projectors wouldn't run the fans for 5 minutes when powered down.


EDIT: Here's my totally made up hypothesis: while the projector is on, the bulb is clearly hot. The fan keeps the glass of the bulb cool, but obviously can't do anything (nor should it) to keep the filament (or whatever the actual light source is) cool. When the power cuts out, the fan stops, as does the light. However, the glass can heat up because the filament (or light producing element) will still be radiating heat. If the glass heats up too much, well then...

Then what? The suspense is killing me!

Thermal shock!

But, where's the earth-shattering 'Ka-Boom'?

That happens when pay for the new bulb.

I don't like your theory, Ken.

When the PJ is powered, the fan removes excess ambient heat from the bulb enclosure, but I doubt it actually lowers the temperature of the bulb glass directly. Sure, if the bulb were on without the fan, then the hot air build-up in the confined space would contribute to a hotter bulb and might actually melt the enclosure.

I think a point we can all agree on is that the less heat a bulb experiences, the longer it will last -- more heat means more entropy means more rapid decay of the filament.

JohnK, sure, when the power cuts out, the heat of the entire system will begin to diminish; however, because it's the total heat over time that determines the longevity of a bulb (absent other forces such as vibration shock), active cooling of a recently extinguished bulb will contribute cumulatively to its longevity.

Yeah, that makes sense too.