Film-Tech Forum ARCHIVE: Booth Ventialtion System

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Posted by Bradley J Sime (Member # 9423) on 04-20-2016, 07:28 PM:

Hello fellow projectionists! This is my first ever post. Been a projectionist for many years.

My question is this...In the summer time it gets hot as hell in the booth. We have a ventilation system (it sort of sucks) and an AC unit, but we still have to resort to ice buckets and fans a couple times a year, which adds stress to an already stressful job. Any suggestions on inexpensive (we're a non-profit cinema society) ways to make the booth cooler?

Posted by Monte L Fullmer (Member # 2797) on 04-20-2016, 07:59 PM:

Welcome.

When I was in similar situations up in the many booths that I operated in and if the auditorium is cool anyway from just sitting overnight, or an actual cooling system, I would open up the port windows during the night, open up the lamphouse (carbon arc) doors, leave the exhaust fan on, and this would help draw some of that cool air in the auditorium through the portholes, so just to beat the heat where it did cool down the booth for the first part of the day while in operation.

Or, if the exhaust stack can be removed from the lamphouse, this will do the same without having to open lamphouse doors especially if xenon lamps are being used.

Posted by Bradley J Sime (Member # 9423) on 04-20-2016, 09:55 PM:

I should mention that our theater also doesn't have air conditioning, and it's the digital projector that's really giving me the headaches, since that's the one I'm using 99% of the time.
A Christie 2210.

Posted by Michael Putlack (Member # 6523) on 04-20-2016, 10:16 PM:

Unrelated, but my flatmates here in Auckland are from Edmonton and recently told me how much they like your cinema!

Posted by Frank Cox (Member # 6258) on 04-21-2016, 12:41 AM:

I have a split air conditioner in my projection room and it works very well indeed. I think I paid around $2000 for it, installed.

You might want to get one of those. It's a lot cheaper than overheating your projector, and a lot more comfy for you when you walk into that room to do something.

Posted by Steve Guttag (Member # 268) on 04-21-2016, 07:17 AM:

The Christie CP2210 really does have a ventilation problem with it. Though how large a lamp you run and how hard you run it play into that.

Even providing it exhaust is troublesome as the air has to draw through the louvers on the side.

Even so, if your booth is getting hot...step one...get the exhaust flange and vent the projector out of the booth (preferably outside)...so you are talking about a fan some duct work and means to prevent down draft/water from getting in.

Get the booth cooler 70F would be a reasonable target.

But also see how hard you are running your lamp too. Also, make sure you don't have very wide variances between scope and flat (or any other format). No xenon lamp likes to go between 50% and 100% all of the time. Christie has a bad "feature" in that they will allow your lamp to be over driven (and under) and essentially cook the lamp. In the current firmware release 4.5.0, they now allow one to "untick" the overdrive feature so your lamp is constrained to its proper operating range. But again, minimize variances between formats as much as possible.

Non-profit or no...it is going to be FAR FAR cheaper to give your projector the proper environment than to pay for a replacement projector because you cooked it. Furthermore, before you get to that point, you will have spent a lot of money fixing the damage you caused and the extra lamps that need not have prematurely died.

Posted by Louis Bornwasser (Member # 3063) on 04-21-2016, 08:20 AM:

It is bad when equipment is the driving force for the comfort of people. I see this with transmitters, too.

Posted by Rex Oliver (Member # 7593) on 04-23-2016, 12:27 AM:

Louis-At the SW transmitter site I am at right now-mid shift.Transmitters are cooled by intake of outside air.These transmitters use forced air and vapor cooling.15 hp main blowers.The main blower cools the cabinet,components in it and the steam condensor that cools the large tubes.250Kw output.The new transmitters are air cooled as well-a 25 hp blower provides supply air from outside.The older CEMCO transmitters have 5Hp cabinet blowers,20 Hp water pumps for the tubes and coils,15 Hp blowers for the water coolers.One 150 ton chiller cools the transmitter hallways.Another chiller cools the front office area.Both run year round.Two boilers provide heat-transmitters provide supplemental heat.More air is needed here than for the commercial plant I used to work at.One of the filament supplies here provides like 12V at 2200A for the PA tube in one of the 500Kw transmitters.One time the tube blew up from just the filament heat alone when one of the tubes water cooling pipes was blocked.The tube water jacket was blown thru the roof of the transmitter adn destroyed a HVAC duct above the Tx.Most of the Tx was destroyed and reqired dedicated work from all of us to rebuild it adn parts from Switzerland.Now those tubes have a safety valve on them that blows if the cooling is blocked.The incident was kinda like what happens to home water heaters whose pipes get blocked.Now that Tx is fine!Was here when it blew-a BOOM thru the whole place and it shook slightly.Glad no one was near the Tx when it let go.

Posted by Jack Ondracek (Member # 1466) on 04-23-2016, 01:01 AM:

Pretty cool to hear some of those old SW rigs are still running.

Nothing quite that fancy in my area though... everything here is air cooled. Not that many tubes left, either. Where I can, I put split ac units in the transmitter rooms and pull the heat out with refrigeration. Much less dust buildup that way. I did the same with the booth at my drive-in.

As for the booth that started this thread... those mini splits are the way to go, if you can get the budget for one. The inverter type will adjust compressor and fan speeds to whatever is needed to maintain temperature.

Posted by Rex Oliver (Member # 7593) on 04-24-2016, 12:20 AM:

We take pride in keeping these old sets going.Its a challenge adn we all do the best we can.Right now two of the rigs are going-250Kw each.The 500Kw transmitters are run at 250Kw the cost of running them at 500Kw is eating the agency budgets.Power cost,tube cost and other parts.And the genset here can't operate a Tx running at 500Kw.The Greenville NC plant is the last VOA domestic site still operating.The Companion "A" plant was closed in 2006.Last week the towers at that site were demolished.You can see it by Googling "WITN VOA A site towers"That site is going to be used by the State of NC as a recreation center.It was sort of depressing seeing those towers come down-I worked at that site for a year.Just hope I can work at the remaining "B" plant for several more years.The sites are shown on a good website of "Jim Hawkins Radio Worild".The transmitters at the A plant have been used as "hanger Queens" to keep B plant transmitters going.The last time I visited A site was sevral years ago on a parts run-the paint was peeling off the walls and mold growing in trasnmitters and walls.The silence was very erie!Noermally you would here the monitors playing the VOA programs and blowers and pumps going.Transformers humming-but quiet there!

Posted by Carsten Kurz (Member # 5396) on 04-25-2016, 09:11 AM:

What Steve says. First, get the projector exhaust air to the outside. If it doesn't solve the issue, get a split air conditioner. DO NOT get one of those cheap monobloc coolers, they are crap!

If you get a split air conditioner, buy it NOW before the summer comes and prices will rise. I usually buy them during the winter when there is low demand. There are cheap ones from around 500US$ up that can be installed D.I.Y. You may be able to find an experienced tech volunteering the install. Depending on your booth situation, it may be more complicated.

I would only recommend one of those cheap ones if cost is a real problem, and if you only need it for some very hot days of the year.

Better brand split air conditioners /inverters can be bought from around 1000US$ up.

- Carsten

Posted by Jack Theakston (Member # 4484) on 04-26-2016, 09:36 PM:

I don't know what the Canadian grant scene is like, but in the US, if you are a non-profit, this is the kind of project you can usually get a local CDBG fund to back. If you can itemize the cost of a small rooftop HVAC and proper ventilation, that's exactly the sort of thing most community development grants cover. This is something you should talk to your development director about applying for.