View Full Version : Air Conditioning in a Cinema
I require some assistance working out the Unit selection for air conditioning in a cinema. I cannot use the normal formula because we have a room packed with patrons within an enclosed darkened space with no windows, etc
As an example:
Cinema one Size is 15 metres x 8 metres x 4.5 metres . Number of seats 186.
There are another 5 screens all of different sizes and number of seats. Is their a formula I could use to determine the heat load for each, my real problem is working out the respiration rates given the large number of people.
I dont want to oversize nor undersize. Any help would be appreciated
The building is an old one, pre world war two type, so has virtually no heating or ventilation installed. Any ventilation is rudimentary. Ceilings are high up.
26-04-2004, 07:17 PM
I saw it done with ductiing under thee seats and special grilles in the foot of the seats.
I have an article - sorry, it's in Dutch - climate in theaters.
I can eventually translate the important issues.
Temperature of bodies is higher the nsurrounding, heat goes up. If you blow the fresh air from the ceiling, then the rsiing warm air will prevent the cooling air to be effective.
Therefore, try to blow the air via the back of the seats or via a grille in the chair foot.
Blowing via the ceiling works very well without peoples in the theater.As sson they arrive, system begins to fail.
Or via the vertical stair steps.µ
Best solution via the back of the seat and mixing the primary air with warmer secundary air.
Fresh air 30 -35 m³/u/person.
MAx temprature 24°C, humidity between 30% and 70%,
Noise lower then 30dBa,preferable 25dBa
Rough calculation: 25 kW to 30 kW.
In Kortrijk Kinepolis (10 cinemas in one comlpex) there is one chiller.
Will give in your case smoother control in partial load.
Latent heat...? What if it's a bad movie with 30 peoples and then Lord of the Rings with 185?
They're sitting still, don't making movements so latent heat will be not that high. (Own rule of thumb: multplie with 1.25 if excessive latent heat can be expected)
Install ducts in sight in the theater like Marc did in the restaurant, blowing the air horizontally and not to high (+/- 3 m)
Speed in the ducts lower then 4 m/sec, speed through the grilels according to the manufactuer so that noise level remains low.
Free cooling possible?
Perhaps 2 smaller units so that a better control is possible in partial load.
take contact with Halton
Use this http://www.haltongroup.com/english/start.htm in meeting rooms of a very big meeting center. http://www.kortrijkxpo.be/homeEN.htm
26-04-2004, 07:48 PM
rooftop unit is good, an economizer added will save energy in cool evenings,
a theater I'm looking after is 70 ton chillers with 30% fresh air. important to keep the old folks awake.
I would go arround 40KW for peaks when place is full in the beginning.
what sort of movies will be there, cause if its ww2 stuff, all will be sleeping so a smaller unit will be required.
sex movies is a different story :D
p.s. is it the old odeon?
26-04-2004, 08:01 PM
Found another article of the royal, sorry Royal Opera in London.
2.200 seats main auditorium, 0 kW heat.
2 AHU's, underfloor, pulsion via roudn grilles under the seats, the cold air is cooled fres outside air 10 l/sec or 36 m³/u/person, speed 0,17 m/sec.
Smalle auditorium, 400 seats.
Total seats the only 10% of the building area.
Total 3 Megawatt cooling cap. - - R134a
Temp. AHU 6°C
Lyric Theater (lots of lights) , underfloor under the seats blowing out,
Exhaust via ceiling and controleld vi CO2 transmitters wqhereby exhaust is adapted.
Im reading all the stuff.......trying to take it all in.......Ive got to see customer tomorrow, I did my site visit four weeks ago, then did nothing, yesterday was a hot day, and now they have been on the phone.
Its one of those old Odeons Chem......when you go inside them they remind you of those days when TV and satellite was not big things.....Saturday nights everyone crammed into these cinemas , trying to grab the back seats, and lots of snogging.......and smoking. The air has still not recovered, you get a feint damp, smell.
The lady who showed me around said........In the beginning its very cold in here, then the customers come and then its unbearably hot.
Well, Im not surprised.
The new owner.....brave man, is having a go trying to inject new life into this complex. There are six screens......the largest one holds 400 people.
I have to go now to see about some air conditioning jobs.......small splits, but it pays the rent.........want to make hay....while the sun shines........I lose Thursday as it is.......Im off to London to that big LG " event" Been invited by LG to a day out of fun in the capital.......
So will try and get some figs together tonight so I can give cinema something to think about tomorrow
26-04-2004, 08:47 PM
Peter, Mike Hardy at http://www.ambthair.com/ is quite an expert on Displacement Air Conditioning which is what you're talking about. Also, a few years back I design a system especially for this, though I will keep quite about the details until I start to sell the systems... if I can get round to it.
i thought mike had retired a while back..
26-04-2004, 09:52 PM
I can't help you duties etc but I used to do manuals for a firm that dealt in cinemas.
What they did was mount an air handling unit in a box under the screen with a couple of vents discharging into the auditorium.
Cooling was via chilled water with the chiller anywhere it could be placed, car park, roof whatever.
Extract air was taken normally via high level grilles a exhausted to atmosphere.
Have fun with it :)
27-04-2004, 12:04 PM
Abe, Trane do these all the time. Use a Voyager rooftop (or a competitor's) with an economiser. I'd talk to the Global National Accounts guys at Trane, they'd probably help you out. The Tel. no. is 01256 306000. Ask for Keith Taylor, as he does most of the cinema stuff. Good luck. :)
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