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We have no AC and 2 projects with one air intake vent and one exhaust fan but it still hits 100! What do you guys do to keep the booth cool?

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Michael Hurley
Impresario

Most manufacturers of sound processors and digital players have a warranty clause no ambient temperatures abov 90F

MIKE <> That air intake doesn't help much when the outside air is 90 plus with high humidity... I piped AC into my booth, but it can still get warm when the weather is really hot... A fan will help, but if you have a booth wall leading to the outside, or a way to vent the heat into that exhaust system, you might be able to cut a hole and install a small (5k BTU, or so) room AC window unit... If your attic has an exhaust fan, that may be a place to dump the the AC heat, also... Is your booth ceiling insulated?... That will help year-round... Bet your amps are not happy with that kind of heat, either...

2 of our 3 booths have no connects to outside walls or ceilings. There's nowhere to dump because it's hot there too. The ac wouldn't he;p[ too much because you'd be sucking the cool out with the exhaust. AC needs a closed system to remove heat. And no: the amps do not like it!

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Michael Hurley
Impresario

OK, it sounds like you need a roof mount compressor/condenser, with remote evaporators in your booths... When the booth AC is on, you would need to block off the room exhausts, and fresh air intakes (but not the lamp exhausts)... Not the least expensive way to do it, but in your particular case, it sounds like the only possibility...

PS <> Is there any way to pipe the Theater's AC into the booths?... THAT is the easiest and least expensive way to go, if it's possible... That's what I did... Of course that would also require blocking off the booth's fresh air intakes, and room exhaust (not lamp exhausts)... You might have to install a booster fan in the duct to get it to the booth, but that's not a big deal... Necessity IS the Mother of invention!...

Just a thought.....would one of those a/c units designed for apartments work. I noticed that the hardware store had some. The thing looked like a dehumidifier, but it was actually an air conditioner unit. It is the type of thing for people who don't have a good size window, the ability to mount the unit to a window, or people who cannot install central air.
I also don't know how efficient this type of thing would be, but it may help out your electronics.

The King

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'The King is only as wise as his Jester'

I just had an A/C unit installed in my booth a couple months ago. It heats and cools and is mounted through an exterior wall. It is sooo much nicer up there now. I don't have any suggestions if you don't have an exterior wall though.

I think what KingJoe is referring to is called an Evaporator; these things work by evaporating water through fan-forced air, but depend upon relatively dry air to work, as in desert areas. In areas of high humidity, they do not work well, and even add to the humidity level.

I can sympathize with you in that heat, Mike. In a theatre where a friend of mine was projectionist over two carbon arcs, the booth got to well over 100 in the summer with the windows of the booth open. He took to wearing nothing but his briefs and shoes, and still sweated like a pig! (the management of the independent subrun wouldn't do anything about the heat, even if they could afford it).

There ARE things that you could do, of course, but they are NOT cheap as you probably imagine. There are three problems:
1) General ambient for the sake of the humans up there. This would require true air conditioning (cooling) by means of a remote, two-part system as Outaframe recommends. These are common in commercial applications and all central home systems are an adaptation of this arrangement with a set of fan-forced coils inside, connected by means of tubing to another set of fan-forced coils and compressor outdoors or on the roof. Trying to use the cooled air from the auditorium poses problems: code often does not allow this, especially if the fire wall must be pierced; the cooling load of the booth would have to be added to the total that the auditorium system is designed to withstand; one would have to provide an air path into and out of the booth (supply and return) to the auditorium, and this would allow more noise from the booth to enter the auditorium(s) -- NOT desireable. The effectiveness of any such a "borrowing" arrangement is not going to be good unless it involves high velocity/volume fans/blowers which require LARGE ducts (3-foot or more in diameter!)

2) The exhaust air for the projectors. This would normally mean that the exhaust fans would draw the cooled air out of the booth, but you could prevent this by putting a supply duct (from the outdoors) opening right under the projector so that the air stream would be right up and over the projector to its exhaust hood. True, some cooled air will still excape through this, but the only alternative is to create a 'jacket' around the projector to contain the air supplied from outdoors up to the exhaust hood/duct. One's local codes might impact this arrangement.

3) The amps. If they fail due to heat, it could be very costly and most inconvenient in the middle of a feature on a hot, humid night when many of your audience are there to cool off. In this case it might be possible to adapt one of those non-compressor coolers (thermionic cooling) sold at Target and camping goods suppliers. If you are handy, it might be possible to buy a large enough one (or build an insulation board enclosure and insert the guts of the cooler into its wall) and thus create a micro-climate for the amplifier, sort of like its own personal refrigerator. This won't do a thing to help the poor guy up there, but at least the amps won't get fried. It will take some trial and error by seeing just how much heat such a unit will remove verses how much heat the amps can create. Put a thermometer inside such an enclosure and take periodic readings of the enclosed temperature. Such units are not designed for long term operation, versus expensive laboratory units which are, but you might experiment for less than $200 in materials. Then again, one of those little mini-refrigerators (usually compressor types) sold for dorm room or apartment use might be simpler and cheaper, if not a little noiseier. You would have to cut a hole through its wall for the cables/wires, but if you are careful, you should not encounter any problems. You would have to check if any defrosting cycles would do too much thermal stress to the amplifiers, however. Resign yourself to the fact that any warranty would be shot for any use of this type. It would also be wise to put a high-temperature alarm inside the unit in case it should fail, in which case it would soon become a 'hot box!'

I wish there were an easy, cheap way to answer these problems, but there isn't. Creating coolness has always been far more expensive than creating heat. Best Wishes. Jim

[This message has been edited by jimor (edited October 06, 2003).]

There are what is called ductless Airconditioners that only require a 4" diameter dryer vent to the outside
I have put several of those in booths with the vent added into the lamphouse exhaust

That is exactly what I meant. I have seen these types of unit in areas where there are no outside windows. Me wordiness fails me sometimes!

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'The King is only as wise as his Jester'

An air conditioner is simply a device that moves heat energy from one place to another. So any true air conditioner has to be vented to an area where the heat can be exhausted from the condenser. Air conditioners also remove moisture from the air by condensing it on the evaporator coil --- so a drain must be provided for the water removed:
http://www.e-toolbox.com/application/8852/8852CH10_How_the_Air_Conditioner_Works.htm
http://www.discountacparts.com/air_conditioning_learning.htm
http://www.kent.net/home-hardware/tips/airconditioning.html

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John P. Pytlak, Senior Technical Specialist
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As mentioned earlier, for air conditioning to work at its best it should re-circulate a percentage of the same air having supply vents and return vents. A certain amount of fresh air is introduced and a like amount of foul air is exhaust from the building. However, in theatres it is often the case where only the public areas are completely covered by the return system. Other areas such as rest rooms, dressing rooms and projection rooms will have exhaust to the outside only, for what should be obvious reasons. These areas cause no great lessening of effciency of the system.

I added a vent from the AC duct leading to the lobby into my projection booth many years ago, and provided a booster fan in that line as well, and keep the booth outside exhaust fan on at all times during operating hours. Not only does this keep the booth at an aacceptable temperture of 75 to 80 degrees, but cools my office as well. My office has no connection to the AC system at all, but opens to the lobby and has a staircase directly to the projection room. By simply keeping my office door open, the booth exhaust fan draws air up the stairs from my office which of course is drawn directly from the lobby which is air conditioned. My office usually stays around 74 degrees when the AC system is running just by pulling that air in from the lobby and sending it up to the booth.

If you can connect your projection room to the central system and have an exhaust fan to the outside (not the lamp exhaust) it should work fine.

[This message has been edited by RoxyVaudeville (edited October 07, 2003).]