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Author Topic: Lamphouse w/o exhaust Dominic Espinosa Phenomenal Film Handler Posts: 1172 From: Boulder Creek, CA. Registered: Jan 2004 posted 08-15-2007 10:25 AM                     I wonder if you guys can give me confirmation on this... It's my understanding that due to statutes regarding the radiation put off by the lamps a xenon lamphouse has to be vented to the outside, correct? And in order to ensure proper cooling, the lamphouse (such as an LP with a 3k lamp) should have it's blower pulling in air from the booth and it's exhaust pulling air out of the lamp house, no? I noticed one of my locations is doing exactly the oposite. We're blowing hot (~90F weather) air into the lamp house instead of exhausting. Thoughts?  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 08-15-2007 10:35 AM                     In some locations codes require that the lamphouse be vented to the outside Normally the internal blower of the lamphouse should draw in cool room air and the vent pipe on the top should be connected to a blower to provide sufficient suction to maintain a negative pressure inside the lamphouse  |  IP: Logged Ken McFall Jedi Master Film Handler Posts: 615 From: Haringey, London. Registered: Apr 2001 posted 08-15-2007 03:02 PM                     I so wish there were some tighter guidelines here in the UK. I look after a small four screen that had lamphouses which were not ducted and you could look in and see the xenon lamp when it was running!! This was more of a concern as the projectors, vic 5's, were at floor level so when standing you looked directly into the lamphouse vent. The lamp houses are 1600w vertical cinemeccanica. Needles to say I have changed this. ALL lamphouses should be ducted and vented outside. Projection rooms get hot enought without all that extra heat to deal with.  |  IP: Logged Rick Deleau Film Handler Posts: 13 From: Portage la Praire, MB, Canada Registered: Mar 2007 posted 08-15-2007 03:31 PM                     Unrelated to this topic. I would like to contact me in regards to buying up some equipment at ps sorry for butting in. Thanks Rick Edit - I would like for Rick Deleau to read the rules page before he posts further. -Brad [ 08-15-2007, 07:02 PM: Message edited by: Brad Miller ]  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 08-15-2007 04:57 PM                        Because dangerous ozone may be formed by either the high voltage ignition or by the UV from the xenon lamp, lamps should be vented to the outside.  |  IP: Logged Michael Moore Expert Film Handler Posts: 188 From: Dover, DE / USA Registered: Jun 2006 posted 08-15-2007 05:46 PM                        Because of the Renovation to the building I'm in, we have no way to truly vent to the outside without making some major architectural changes, however I have been running now almost every Sunday and Wednesday night by venting to the air return of the booth form the AC. It is the only way vent it out. It's all I have been able to do, The AC Unit is right above the Lamp house, Also even after a long movie 2 hours or more the room never gets over 80F Mike  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 08-15-2007 05:55 PM                        I've seen lamps up to 2kw vented into the booth (see photos of the Wellesley College cinema). It is also common for 16mm and video projectors (with xenon lamps from 350w to 2kw) to not have outside exhaust. It doesn't seem to cause any major issues, but it is probably a) not very good for bulb life and b) probably not a good idea for a venue that would run film every day.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 08-15-2007 06:39 PM                     I have run 3kw exhaust into the room for portable work. Its only for the duration of one or two showings though. Mark  |  IP: Logged Dominic Espinosa Phenomenal Film Handler Posts: 1172 From: Boulder Creek, CA. Registered: Jan 2004 posted 08-15-2007 06:55 PM                     Hey, Mr. P! Long time no see, probably since I've been running around all this time. Good to see you though. The question I really have is this: if I have NO outside exhaust BUT I'm blowing hot, dirty air, from the outside of the building am I reducing the life of the lamp?  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 08-15-2007 10:31 PM                     So, the questions are: 1) is the bulb getting adequate cooling 2) is the contaminated air from outside causing a problem? For (1), what it really comes down to is how much air is moving over the envelope of the bulb. Lamphouses are generally designed to pull air past the bulb envelope, and I wouldn't think reversing the direction of the exhaust fan would have that effect. None of the measurements are easy to do; probably your best bet is to measure the temperature of the air coming out of the lamphouse, and perhaps of the lamphouse and projector itself. Also, how much airflow are you getting? For (2), well, how dirty is your air? If you don't get particles of crap that touch the bulb or reflector and stick to it, then it's probably fine. And I'd be surprised if your air was that dirty. You should be able to answer some of this empirically -- how much life are you getting out of these bulbs? All 3 of the intake fan on the lamphouse, the exhaust fan on the lamphouse, and the main exhaust fan are all running backwards? How did it end up this way? Modern bulbs are "Ozone-free" (OFR), meaning that, once struck, their glass filters out the ionizing radiation that makes ozone. So theoretically you only get ozone at ignition time, when the wavelength of light is different. So it probably not a major issue to have OFR lamps exhausing into the booth, but it is certainly not the right way to engineer the system. --jhawk  |  IP: Logged Bryan M. Montgomery Film Handler Posts: 47 From: Chillicothe, Ohio Registered: Jul 2007 posted 08-16-2007 12:46 AM                        If you have no lamphouse ventilation, the forced air system will be rendered nearly useless after a while, which in my experience leads to excessive heat build-up and premature seal failure on the bulbs. Venting to the air return ducting may work as long as your HVAC is running. I've had roof fans fail many,many times and have come up with an excelent emergency fan that I place between the lamphouse and the flexible ducting we have. Be creative and come up with a solution.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 08-16-2007 09:51 AM                     quote: Dominic Espinosa I noticed one of my locations is doing exactly the oposite. We're blowing hot (~90F weather) air into the lamp house instead of exhausting. Is there an air flow vane switch and has it been bypassed? It seems to me someone simply installed the blower incorrectly. Pulling outside air into the lamphouse has to be making the inside of that lamphouse fairly dirty unless there is a filter installed, which I would highly doubt. I would go ahead reverse the blower so that it is exhausting correctly.  |  IP: Logged Dominic Espinosa Phenomenal Film Handler Posts: 1172 From: Boulder Creek, CA. Registered: Jan 2004 posted 08-16-2007 01:36 PM                     No air vane installed in this bad-boy! I just don't see how it could ever cool efficiently if we're blowing air into the front of the lamphouse via the squirrel cage fan and then blowing even more air into the rear of the lamphouse via the stack. Moreover you simply can't touch the projector after the thing's been running for ~10 minutes. The trap is too hot to handle! This just doesn't seem right for a lamp this small. I think I'm going to take some temp measurements.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 08-16-2007 03:33 PM                     What kind of blower is installed on the roof? Mushroom type, upblast, ect? I wouldn't even bother taking temp readings. Just try and get the air flow exhausting out as it should be. If you're not sure how then have an HVAC tech come out to do it.  |  IP: Logged Brad Allen Jedi Master Film Handler Posts: 688 From: Evansville, IN, USA Registered: May 2000 posted 08-17-2007 01:34 PM                     Are you sure the blower hasn't been wired incorrectly and it's running backwards?  |  IP: Logged

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