Film-Tech Forum ARCHIVE: Projection Booth requirements?

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Posted by James Waite (Member # 4536) on 10-28-2009, 09:34 PM:

There's some talk of moving the theatre I run into a different room in this building. I'm on a campus. I've been asked to give them the specs of what would be needed in terms of electrical and venting. I wasn't here when this booth was built and I can't exactly remember what all is needed. I though some of you fine people would be able to help?

Here is what I think is needed. Feel free to correct or add anything you think I might have missed.

Projector:
2 110 outlets.

Platter
1 110 outlet.

Rectifier
220 volt 3 phase power? How many amps?

How many outlets would a surround sound system need?

I'm running a 2000 watt bulb, how much ventilation does that require? Does the venting have to go outside or can it be redirected into the building?

then there's misc outlets for rewind bench, make up table etc.

Is there anything I haven't thought of?

Thanks for your help.

Posted by Tony Bandiera Jr (Member # 2365) on 10-28-2009, 11:59 PM:

James:

You're pretty close on the power requirements. Here's what I spec as a minimum:

1- 20amp 120v for projector motor, each machine;
1- 20 amp 120v for dowsers, etc. one circuit for both machines;
1- 30 amp, three phase for each rectifier;
1 - 20 amp outlet circuit will suffice for rewind bench, etc. Place the outlets where needed. Only your booth layout will know where.

For sound racks, a MINIMUM of 4 -20 amp, 120v circuits, one circuit for the processor, booth monitor and other gear ahead of the amplifiers, and circuits for the amplifiers that I group as
left and right, center and surround, and subs.

Ventilation WILL be your biggest pain in the ass to deal with, as anyone who has never dealt with projection gear will argue endlessly over why it is needed and in the CFM needed. With that said:

A MINIMUM of 450 CFM, measured at a 6" dia. stack located just above the lamphouse. 600 CFM would be best, but don't go over that as too much cooling can cause problems as well.

**STAND YOUR GROUND ON THE VENT REQUIREMENTS, DON'T LET ANYONE SHORTCHANGE IT FOR ANY REASON or you WILL pay for it later in increased bulb and reflector failures!!

Also make sure that the lamp exhaust blower is under the EXCLUSIVE control of the projectionist, don't allow it to be tied into any building energy management systems!! UC Irvine has learned this expensive lesson the hard way with damage to a $3,000 glass reflector in a Kinoton lamphouse.

A 2k lamp will in most areas be required by building codes to be vented outdoors. You might get away with venting into the building, but I wouldn't try it.

Booth lighting should be a mix of general lighting (fluorscent lamps) for setup and maintenance, and dimmable downlights for use when the films are running. A wall-mounted track light on a dimmer to act as a projector worklight would be a good idea too.

Watch for my upcoming pics of my current install to be posted to the picture gallery here on F-T.

Posted by Frank Angel (Member # 248) on 10-30-2009, 02:15 AM:

Tony hit all the right spots. And about the ventilation control - It's something even the electrical designers don't take into account. We had a very bad situation here on that same note -- the booth vent fans were controlled by nice big press on (green) - press off (red) industrial-type button switches with a big 7w green pilot light on the booth wall, but no one knew that down 6 stories below in the bowels of the building was a maintenance room with electrical panels and, yes, you guessed it, identical switches that paralleled the ones up in the booth.

I had been running that booth for maybe 10 years and never was there any indication that there was a clone of the switches elsewhere until one night when I was running a late show, I started to feel light-headed and even a little nauseous. I began to have a funny taste in my mouth and the room seemed to be hazing up. Some fool from the college maintenance dept was wandering around that electrical room and saw buttons with lights lit up. And he turned them off....hey they were shiney things, what more reason did he need? The college you see closes on the weekends and it's hard to get it thru their heads that the weekends are when we work.

Anyway, I realized in time that the exhaust had been turned off. In a carbon arc booth, it is even more dangerous than xenon given the toxic crap, including carbon monoxide, that a carbon arc lamphouse spews out if it's not seriously exhaused. So as Tony points out, yell and make lots of noise now in the planning stage, else you will have to be fixing that mistake later down the line and probably on your own.

Me, I just went down to the electrical room in the basement, opened up the switch box and disconnected and tied off the wires. Put a big sign on it too: "This switch as been disabled for critical safety reasons. Reconnect it under pain of....well, have you seen THE TEXAS CHAINSAW MASACRE?"

Posted by Martin McCaffery (Member # 37) on 10-30-2009, 08:32 AM:

OT: How many people on this list (probably we older members) have been hit with a bout of carbon monoxide poisoning while working in a booth?

I had it happen to me once and it ain't fun.

Posted by Mark Gulbrandsen (Member # 72) on 10-30-2009, 09:29 AM:

quote: Tony Bandiera Jr
600 CFM would be best, but don't go over that as too much cooling can cause problems as well.

Oh come on Tony... when is the last time you were ever able to over cool a lamp?? It ain't happenning! I always spec about 800 cfm+/- for a 2kw. 400 is just enough for a 1kw lamp. 1200cfm for a 3kw and 1600cfm for a 4kw to 6kw.

Mark

Posted by Scott Norwood (Member # 30) on 10-30-2009, 11:24 AM:

This has nothing to do with electrical or HVAC requirements, but definitely make sure that you get one more set of portholes than you have projectors. At some time, you will no doubt have a need to use a video projector, 16mm projector, or slide projector, and you will be glad to have an extra set of portholes for this purpose. A large followspot port with a fire shutter (or other means of closing it) would be desirable as well, should you ever need to use a followspot or other device which requires a larger than normal porthole.

Posted by Rick Raskin (Member # 1561) on 10-30-2009, 02:10 PM:

quote: Martin McCaffery
OT: How many people on this list (probably we older members) have been hit with a bout of carbon monoxide poisoning while working in a booth?

OT Reply, sort of: While working Theater #1 at Ft. Benning, GA in 1968 the operator from Theater #9 called and asked me what to do since the exhaust motor had burned out in his booth, which was stand alone inside the theater with no outside window. I advised him not to run the show, which is what he did. The theater manager was upset and seemed to think it would have been okay to just enter the booth for changeovers and thread-ups. Right!

Posted by John Walsh (Member # 168) on 10-30-2009, 02:46 PM:

The only minor thing I would add regarding the cfm airflow is sometimes the HVAC system can not supply enough air into the projection room, to be able to get the required amount out. So, I would suggest a simple vent that just goes from nearby the projector to the outside. This is what they did in the carbon arc days.

All vents should be as large and with as few turns as possible.

Often, no one wants to pay to pay heat (or cool) air which is pulled through the lamphouse and 'thrown away' so exhaust rate is lowered.

Posted by Mark Gulbrandsen (Member # 72) on 10-30-2009, 03:01 PM:

Good point John and I've run into exactly this on many occasions. All to often the contracting HVAC person doesn't bother to find out the stack draw on a given building.

Also the room he is wanting to move the equipment into may have to be sprinkled and you will also probably need an electrical damper on the exhaust blower in order to meet fire codes. I ran into the latter on a job last summer at MSU but the University electrician we were provided with was super, and very familiar with the University's codes and had already installed the damper!! The U's codes were actually more stringent that NEC.

On the other hand if you put quick dossconnects on all the equipment so it can be plugged in and unplugged you may be able to get around all the codes because then your system is considered portable.

Mark

Posted by Jarret Chessell (Member # 5077) on 10-31-2009, 01:00 PM:

It might be worth making concessions for a digital cinema projector now too. Given your location it might be nice to be able to show both D cinema and 35mm in future years. Putting a video projector right in your booth would likely make things easier for rentals too.

Posted by James Waite (Member # 4536) on 10-31-2009, 09:46 PM:

Thanks for your help. I hadn't thought ahead about the video projector. I suppose I would just double up everything? They probably use the same power and venting as a film projector since they use the same bulbs?

Posted by Demetris Thoupis (Member # 833) on 11-01-2009, 01:54 AM:

Not necessarily. If you will be using also 3D applications you will need almost tripple the lamp used for 35mm applications in your d-cinema. Make sure you have separate two exhaust conduits and not one common for your D-Cine and 35mm for your might lead exhausting the D-Cine projector into your 35mm!!
Demetris

Posted by Jarret Chessell (Member # 5077) on 11-01-2009, 01:57 PM:

I would be more worried about the booth layout so you make sure you have room for the added D cinema projector. I'd have a second booth window added for it now to save that hassle (you can put some decorative blinds in it for now). As Demetris suggested, considering the exhaust right now would be a good idea to make sure that will be right (and I imagine you'll need more airflow on it). If the electricians put an electrical distribution panel in your booth (as i'd imagine they will), it should be easy to expand your electrical needs in the future.
If I were you, I would also get rid of your cp-65 and let me take it off your hands, and install a cp-500 or 650 [Big Grin]

Posted by Steven J Hart (Member # 2340) on 11-05-2009, 08:50 AM:

quote: Martin McCaffery
OT: How many people on this list (probably we older members) have been hit with a bout of carbon monoxide poisoning while working in a booth?

When I started renovating my theater back in 1998. The pair of Peerless Magnarcs were simply ducted into a rotary spinner on the roof top! No fans at all. I ran the booth once just for fun before ripping out the old equipment with no ill-effect but wonder how that worked out during hot humid calm evenings with no wind to create a draft?

Posted by Jon Miller (Member # 163) on 11-05-2009, 09:06 PM:

quote:
Make sure you have separate two exhaust conduits and not one common for your D-Cine and 35mm for your might lead exhausting the D-Cine projector into your 35mm!!

Another reason for separately exhausting your digital cinema and 35mm lamphouses is, if you plan on hosting film festivals, you can make a fairly quick changeover from digital to 35mm if you use your d-cinema projector for video projection and the show contains both video and 35mm (say, a promotional trailer on DVD and a 35mm feature or a shorts program with a combination of video and 35mm subjects).

Switching a single duct between projectors slows the video-to-35mm switch, compromising showmanship, and can shorten the life of the d-cinema projector's lamp from not cooling down the projector properly.

Posted by Scott Norwood (Member # 30) on 11-06-2009, 11:41 AM:

Why is it that two or more film projectors can (and usually do) share the same lamp exhaust, but a [dlp]

projector can't?

Posted by Demetris Thoupis (Member # 833) on 11-06-2009, 12:26 PM:

Because you mind end up with a Sony DC Projector and Sony always want exclusive things [Big Grin]

On the side note though, If you use 3D you need tripple the light than 2D and thus the exhaust fan of the Digital projector will be blowing faster than the film projectors in this case causing hot air going back into the film projectors. Film projectors usually have the same exhaust fans and thus you don't have this problem although it is better to exhaust each projector separately.
Demetris

Posted by Kenneth Ivan Lavigne (Member # 5539) on 12-19-2009, 12:16 PM:

Hey, it's grate to be on this here foram. We is converting over our film booth to digital at our theatre. My helper, Bobby Jr. got me a Casio model#xj 5c215-w on sale an I need help hooking it up to a panasonic dvd/vcr ,modeldmr-ez48vk. We also picked up a samsung blue ray-disc player with 1080 pixies output an a sony bravia internet link(last one on the shelf). As soon as we get these together, we'll be reddy to show DVds easy. Has anyone ever done this before? [beer]

Posted by Richard May (Member # 2627) on 12-19-2009, 12:24 PM:

LMFAO!!!!!!!

Posted by Stephen Furley (Member # 1277) on 12-19-2009, 12:38 PM:

I've seen several places where they do. At Pictureville, Bradford, for example a side branch off the extract from the centre Cinerama machine serves the digital.

Posted by Tim Reed (Member # 137) on 12-19-2009, 09:53 PM:

There are several theatres in my territory running Blu-Rays of "Elf", since the distributor couldn't supply enough prints. They actually told them to go to the store and buy the movie on Blu-Ray! From the DVI input of their regular Digital Cinema projectors, it looked darned good on the screen. However, I suggested they cue it up PAST the "Warner Home Video" logo... just for the sake of P.R.

Also, some of the high-end OSA projectors have been used to project DVDs in the past, with surprisingly good results. It's totally non-professional, of course, but it ain't bad.

Posted by Ken Lackner (Member # 1002) on 12-22-2009, 09:11 PM:

quote: Tony Bandiera Jr
Also make sure that the lamp exhaust blower is under the EXCLUSIVE control of the projectionist, don't allow it to be tied into any building energy management systems!! UC Irvine has learned this expensive lesson the hard way with damage to a $3,000 glass reflector in a Kinoton lamphouse.

Tony, I am curious, how was the reflector damaged? Was it destroyed from a lamp explosion that resulted from improper cooling, or was was reflector itself damaged over time due to improper cooling? The reason I ask is because I thought those glass reflectors were pretty tough and rather forgiving of poor cooling situations.

quote:
Make sure you have separate two exhaust conduits and not one common for your D-Cine and 35mm for your might lead exhausting the D-Cine projector into your 35mm!!

You could put a damper above each projector that would be open for the projector in use and closed for the other projector so that the air that is vented from the projector in use can not go back in to the other projector. Of course the other point about sharing digital and film in the same presentation is still a valid one.

Posted by Tony Bandiera Jr (Member # 2365) on 12-22-2009, 11:11 PM:

Ken, the reflector lost it's coating in the area of the arc's focus from excessive heat, luckily the bulb didn't explode, but I'm concerned that it's only a matter of time before the reflector shatters which will of course explode the bulb. I have a picture of it somewhere and will post it in a new thread when I find it. [Smile]