Film-Tech Forum ARCHIVE: Projector/Console Ventilation

This is topic Projector/Console Ventilation in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Andrew McCrea (Member # 674) on 03-18-2001, 09:12 AM:

One quick question...

The ventilation pipe on to of the console/projector... is it air conditioning or exaust?

------------------
Andrew McCrea

"I'm Not Bad, I'm Just Drawn That Way!" - Jessica Rabbit

Posted by Ken Layton (Member # 133) on 03-18-2001, 10:52 AM:

Exhaust. It usually is either a 6" or 8" diameter duct.

Posted by Gordon McLeod (Member # 33) on 03-18-2001, 10:59 AM:

exhaust with 150 -700 cfm at 6 or 8" opening
In most areas in Canada it is legally required to be vented directly to the outside enviroment

Posted by John Pytlak (Member # 331) on 03-18-2001, 07:13 PM:

Even "ozone free" xenon lamps produce a bit of ozone (the high voltage ignition and ultraviolet energy break down oxygen molecules that then recombine into ozone), which is not good for your health. So all lamps should be vented. The large amounts of heat also need to be vented outside, or the projection room quickly becomes hot and dry.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Mark Gulbrandsen (Member # 72) on 03-18-2001, 08:09 PM:

If you are running 2KW or above go with the largest blower you can. I reccomend the higher CFM around at least 700.Even larger lamps require more. This will allow you to get maximum life, plus more out of the lamp.
Mark

Posted by Gordon McLeod (Member # 33) on 03-19-2001, 07:29 AM:

Actually you can over cool xenon lamps and as such always follow the manufacturers recomendations for the exhaust requirements
Overcooling can cause thorium migration quartz blacking and unstability

Posted by Barry Floyd (Member # 385) on 02-24-2003, 05:31 PM:

Am I out of line by telling the HVAC engineer to provide for 900 CFM on the exhaust stack for my 4kw Xenex II lamphouse?

Finding an exhaust fan to pull that kind of CFM's is not hard, but increasing the size of the HVAC unit to compensate for the amount of air exhausted from the room is expensive?

Does anybody know of a better way to provide "make-up" air to the projection booth? What about "outside air"?

Posted by Will Kutler (Member # 770) on 02-24-2003, 06:00 PM:

As for lamp exhaust, follow the manufacturer's recommendation. I do believe that both Christie and Strong provide all of the tech info regarding proper equipment recommendations/usages in their product brocheures.

Posted by Bernard Tonks (Member # 809) on 02-24-2003, 06:08 PM:

Havn't seen this method of ventilation since carbon days. Any advantages?

Picture taken from Kinepolis Switzerland 8 by Mike Baer.

Posted by Richard Fowler (Member # 893) on 02-24-2003, 06:46 PM:

I have done the same situation on some of my multiplex projects with the booster fan and negative exhaust...easier to balance out and no chance of dumping hot exhaust into a console that is not on or situated at the end of the run.
Richard Fowler
Kinoton America Inc.

Posted by David Stambaugh (Member # 1102) on 02-24-2003, 06:53 PM:

Are you saying that each lamphouse exhaust in a typical multiplex may share common ductwork with other lamphouses? Like "X" number of lamphouse exhausts converge in 1 vent outside? Maybe I'm misunderstanding. [Confused]

[For a second there I thought Andrew McCrea was back! [Wink]

]

Posted by Daryl C. W. O'Shea (Member # 1303) on 02-24-2003, 07:17 PM:

Yeah Dave, I've seen some installations with only one outside stack. It's probably a carry over from change-over booths which normally only had a single outside stack.

Personally I don't like having only one outside stack in a multiplex. If your outside motor dies you might end up with a booth full of hot lamphouses, whereas with individual stacks, if one dies only one lamphouse gets hot. Of course, with one outside stack you have a lot less snow to shovel when the snow drift gets too deep. [Smile]

Barry, I've always wanted to try (in a fairly warm climate -- certainly not in Canada during the winter) having an outside airduct fed into the bottom of the console to reduce the amount of air drawn from the room. You'd have to be careful about not having really cold drafts though.

Posted by David Favel (Member # 1125) on 02-24-2003, 07:59 PM:

Yea, I was about to wish Andrew a happy birthday...

Posted by David Stambaugh (Member # 1102) on 02-24-2003, 08:07 PM:

So if 1 stack is shared by, say, 6 lamphouses, you're saying there's possibly only 1 exhaust fan for all 6 (presumably at the stack)? Well, I gotta say, even to a dumb-as-a-bag-of-hammers, non-film-handler like me, that just sounds like a wrong-headed way to design a cooling system that's protecting a lot of expensive equipment. [Eek!]

Are those exhaust fans typically belt-driven? Belt breaks, nobody's paying attention... Sounds like a recipe for a costly "incident".

Posted by Daryl C. W. O'Shea (Member # 1303) on 02-24-2003, 08:10 PM:

Usually you would have a motor/fan above each projector and one at the end, outside.

Some older ones use belts, most new ones use direct drive fans.

Posted by Will Kutler (Member # 770) on 02-24-2003, 08:38 PM:

Each projector should have its own exhaust system.

AND REMEMBER THAT THE EXHAUST SYSTEMS DO NEED TO BE MAINTAINED! this means going on the roof with a hand held grease gun and greasing the bearings via the zerc fittings...like doing your car. Exhaust fan belts also need to be maintained and replaced as needed. all of this should be part of your routine maintenance.

At the theatre where I worked, this simple task turned into a real fiasco that did result in interrupted shows with refunds to customers. The G.M. at the time could not figure out if this was the responsibility of the HVAC company as part of their routine building maintenance contract, or of the building custodian. As a result of the office politics, this simple task never got done. This resulted in fan bearings crapping out and fan belts breaking...and the Xenon shutting down because exhaust air was not holding the microswitch inside the exhaust duct open. Several times, as a "temp" fix, booth personnel would have to let the xenon cool, open up the lamphouse, tape the microswitch up, open up back of lamphouse (Christie Console) and use a floor fan to pull out exhaust....not really a recommended practice. I solved the problem by pitching a bitch and got the $$ to buy a friggin grease gun...and proceeded to take care of it on my own...

Also, it is recommended practice to clean the squirrel cage(s) in the lamphouse, and also the ones used on the projector itself.

If you are using a Christie Console, look at the instruction/maintenance manual for reference to lubing (oiling) exhaust system bearings in and around lamphouse.

STAY AWAY FROM W-D 40!!!! use a good sewing machine oil...or even Marvel Mystery Oil......

Posted by Brad Miller (Member # 2) on 02-25-2003, 12:35 AM:

Barry, yes I would say 900 CFM would be perfect for your 4K console. (When in doubt, it's best to overdo it just a tad, although 750 CFM would probably suffice.) You should get excellent lamp life with that kind of exhaust. [thumbsup]

Posted by John Pytlak (Member # 331) on 02-25-2003, 10:08 AM:

Barry: You're planning on air-conditioning your drive-in booth? [Confused]

Posted by Manny Knowles (Member # 1171) on 02-25-2003, 10:37 AM:

Some time back, I posted a question about a lamphouse that was constantly killing lamps at a faster rate than the others of the same model at the same multiplex.

In the absence of any apparent electrical faults and based on various Film-Tech responses and also in consideration of the fact that this particular projector is "at the end of the line" in the exhaust scheme, I am almost certain that these lamp failures are a result of inadequate cooling/exhaust.

The lamps don't explode. The ends are not charred or discolored. They come out looking just fine, or else the envelope is all blue-purple inside. Everyone seems in agreement that this is a symptom of the lamp's seals failing, which could be due to overheating.

Posted by Barry Floyd (Member # 385) on 02-25-2003, 12:23 PM:

quote:
Barry: You're planning on air-conditioning your drive-in booth?

Yes, our building is 34'-8" x 60'-0" on the main ground level and 34'-8" x 22'-8" upstairs. The downstairs is laid out where the Mens & Womens restrooms are at the rear of the building, the lobby area is in the center, and the concessions line and kitchen area are on the opposite end of the building from the restrooms. Directly above the kitchen and concessions line is the projection booth, office and a small restroom.

The downstairs HVAC unit is spec'd as a 5 ton electric heat pump (both heating and cooling), and the upstairs unit is the same. By looking at the drawings and specs, he (the HVAC guy)upsized the unit on the second floor to compensate for the amount of air exhausted by the lamphouse. Downstairs it's the same thing, but instead of compensating for the lamp, it's the exhaust hood above the fryers and grill.

Posted by John Pytlak (Member # 331) on 02-25-2003, 01:16 PM:

Consider mixing in some outside (unconditioned) air for the lamphouse cooling. Just not too cold or too damp. Use a HEPA filter to keep the air supply clean.

Posted by Andrew Lee (Member # 1330) on 02-25-2003, 02:00 PM:

I would also look at the specification of static or vacuum measured in "inches of water". This measurement is important and can easily be done with a manometer (tube filled with water and measured off in inches at the waterline). You can have the proper flow when measured at the lamphouse, but how much "power" does your exhaust system have to maintain this spec when everything is running and other exhaust vents are hooked up. I say this because sometimes flow measurements are made prior to equipment installation by the contractor. These measurements are then taken for gospel and in most instances are not what you are actually getting.

Posted by Peter Hall (Member # 695) on 02-26-2003, 11:20 AM:

900 cfm can "suck" the douser on a Super / Ultra 80 open ! We tend to put a independant 600CFM fan on the lamphouse - assuming the booth extract is >600 then all is well. If below the flue will get hot - otherwise a smoke test (in the booth - god forbid - are Marlboro Lights a tax deductable ?) will show up any extract probs..