NEC NC1200C venting into booth temporarily

[Darin Steffl]

Our projector exhaust fan on the roof just failed today. We want to fix it soon but there's no guarantee that will happen in a timely manner with contractors being busy, supply shortages, etc.

I've read that it's not allowed or not advised to vent the exhaust from a Digital Xenon projector into the projector booth due to possible ozone exposure.

Some posts say the ozone emitted is so small that it's fine but there is a chance there could be more ozone emitted than is healthy.

We're looking at this temporarily until it's fixed or until we upgrade to a Laser projector this spring/summer that no longer requires external exhaust.

Should we absolutely NOT vent into the building, vent to the inside temporarily, or fix the roof exhaust as soon as possible to be safe?

I'm new at this so please educate me

[Marcel Birgelen]

There are lots of factors involved here, including how big the room is you're venting into and how well that room in itself is ventilated and how long the projector will be running during the day.

Maximum advisable concentrations are between 0.07 and 0.08 ppm, but local regulations may differ so you may want to check on it. An ozone level meter can be bought for about $50 to $150, which can tell you if you come close or exceed those values and in that case, you should fix your ventilation.

[Darin Steffl]

There are lots of factors involved here, including how big the room is you're venting into and how well that room in itself is ventilated and how long the projector will be running during the day.

Maximum advisable concentrations are between 0.07 and 0.08 ppm, but local regulations may differ so you may want to check on it. An ozone level meter can be bought for about $50 to $150, which can tell you if you come close or exceed those values and in that case, you should fix your ventilation.

Thanks for the info. We're about 98% certain we're upgrading to Laser in the next 6 months so if we need to continue venting to the outside until then, we'll try to band aid fix it until then. We're not sure what the problem is yet as it just failed to turn on half hour before my post. It could be a bad breaker in our panel or a dead motor. It literally was working today for an hour during testing of our next movie, I turned it off for 20 mins, then showed my Dad how to turn it on and it failed to work so something goofy is happening.

[Mark Gulbrandsen]

It's fine, I've done it before when.a Fantech did not arrive in time. All the S-2 NEC's are thermally monitored and if something over heats, it will shut down the lamp. I'd reccomend a test run of your film first, as I'm not familiar with your booth size available ventillation, doors, etc. If you do end up doing it then check it frequently...

[Darin Steffl]

It's fine, I've done it before when.a Fantech did not arrive in time. All the S-2 NEC's are thermally monitored and if something over heats it will shut down the lamp. I'd reccomend a test run of your film first, as I'm not familiar with your booth size available ventillation, doors, etc. If you do end up doing it then check it frequently...

I'm most worried about safety. If the ozone produced is dangerous, I don't want to vent inside at all. We can vent enough air out of the booth to storage areas without people but my main concern is safety over anything else.

Should all xenon bulbs nowadays be ozone free or very little?

[Mark Gulbrandsen]

All cinema and stage lamps are ozone free because of a chemical mixed in with the glass when it's produce...

[Mark Gulbrandsen]

Am also assuming you are using a good quality lamp and not a Chinese lamp....

[Kyle Mikolajczyk]

Yeah if you don't believe the "no ozone" part you should see if you can find the box for the lamp. Ours explicitly says "Ozone-free". Although I was once told that if you are not exhausting the lamp and it explodes you risk venting the crystals into the air.

[Leo Enticknap]

That's what I'd be more worried about. I don't think there's a grille in the vent manifold to catch any very hot and very sharp crud that could try to exit the lamphouse if the bulb did explode. There is in the Barco lamphouse cartridge/module things, but that extra layer of protection isn't there in a NEC or a Christie.

[Darin Steffl]

That's what I'd be more worried about. I don't think there's a grille in the vent manifold to catch any very hot and very sharp crud that could try to exit the lamphouse if the bulb did explode. There is in the Barco lamphouse cartridge/module things, but that extra layer of protection isn't there in a NEC or a Christie.

Our NEC shuts down the lamp if it gets too hot. We've accidentally forgotten to turn on the exhaust fan once and it has shutdown on it's own and given a lamp overheat error. I suppose this doesn't guarantee a bulb won't explode but it has some protection built in to keep it from running too hot.

[Marcel Birgelen]

Most modern xenon lamps have coatings that block most of the light that produces ozone, so the ozone load coming from your projector will be pretty low. Ozone-free is pretty much a myth though, there will always be some ozone produced, given the temperatures at work here. Your average laser printer may produce more ozone than your projector, but it's always good to check on it. Ozone meters are pretty cheap and accurate and ensure your workplace complies with the regulations. While ozone may not be as toxic like e.g. chlorine, prolonged overexposure still can have quite severe effects.

As for the lamp exploding: This is a remaining risk. There isn't much toxic stuff in there that will remain airborne for long, but there may be some serious risk of injury if some of the stuff exits through the exhaust manifold. I guess the risk can be greatly reduced by putting an open pipe of e.g. 15 inches in height on top of it. That way, any debris exiting that way should be funneled mostly upward.

[Mark Gulbrandsen]

Actually, the way the air flows through the NC-1200 and 2000, any and all debris should be contained within. But the reflector and heat filter will also end up in pieces and they are expensive.. This is the main reason I alwajys use Ushio Lamps. Never had one explode under normal circumsttances and then only one that blew in a Christie S-1 that had a firmware bug.