What type of lighting does the architect or lighting designer have in mind?
Are you looking for a watts lighting per area estimate for preliminary load calc?
New Energy Consevation Codes usually have an allowable lighting load number that is a requirment, usually between 0.8 to 1.5 watts per square foot. You may want to use that for an initial starting point.
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Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
i want to calculate cooling load for indoor stadium for that i need lighting load A&E Given the lighting load in terms of lux i.e 1600 lux but i have to give the input in trems of watts/sq.ft.
You're asking for something that doesn't exist. There is no direct correlation between lux and watts per square foot. Light intensity or efficiency of different types of light fixtures will vary.
For example a 60w incandescent and 28w compact fluorescent will have similar light outputs and produce a similar lux reading, but obviously the incandescent is less efficient.
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Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
I don't think that Ashrae recommends lighting levels. IESNA has recommendations for various sports and facilities for lighting levels. The NFL wants 300 fc horizontal and 200 fc vertical. The NBA wants 250 fc horizontal and 125 fc vertical. For a high school gym, 50 fc is considered adequate. 100 fc is generally considered the minimum for arenas or indoor stadiums.
I am not a lighting engineer, but my understanding is that the energy level is 1/683 W per sq-ft of lighted area at 1 fc. So the energy on the playing surface is 100/683 W. MH lamp efficiency is about 20%. The light fixture, luminaire, will only deliver a portion of the light produced by the lamp. However some of the light hitting the playing surface will be re- reflected back to the surface by surrounding walls and ceiling. If the luminaires and the re-reflection can deliver 70% of the light to the playing surface, then the power requirement is something like 100/(683*.2*.70) = 1.05 W per sq-ft.
I am impressed! You've obviously been there and have done that. (and sound like you might be able to write the book)
Two comments.
An indoor stadium or arena will have various lighting requirements for different areas. Seating areas will be less than playing surface, concession areas will be different, etc.
How do you propose to deal with or handle this heat load? If the arena is tall enough can heat stratification be taken advantage and just ventilate the excess heat? Does it need to be "air conditioned" out of the space?
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Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
For MH 20% of energy is light, 30% is IR, about 3% UV. So a lot of the heat will make it to the surface as radiation. However load due to spectators could be several times that of the lighting.
Exhausts at the roof are typical. After all heat rises. Return air is usually located at a lower level than the exhausts. Ventilation requirements are high. The cooling load for ventilation can be several times that of the lighting and occupancy load.
I think that if you got 20 fc in the spectator area, that would be sufficient.
Heat Load - ASHRAE Standards
Re: Heat Load - ASHRAE Standards
