Office,Lab and conference room lighting and recpt. requirements

[pms_electric]

Hi guys need some help. I've been asked to come up with the amount of lights(2x4 lay-in for office, 8ft strip in shop and warehouse) and recpt. needed to meet code requirements for an office/lab/warehouse building.

I have found table 220.12 for lighting loads and article 220.14(k) for recpt. loads. Saying 3.5 va per sqft for lighting in office and 1/4 va per sqft warehouse. Also 1 va per sqft for recpt.

My problem is this doen't help me figure the number of lights or recpt. needed per code. I have had people say 35 candles of light in an office and 5 candles in a hallway.

Is there a good formula or rule of thumb I can use for lights per sqft. or recpts. in a commerical building?

Thanks

 

[augie47]

The NEC has no requirement on the number of lights and very limited requirements on where there must be any.
Some, if not all, of the building/fire Codes have minimum lighting requirements for particular areas, but those are often less than the customer would want.
The number of receptacles and the amount of light is controlled mostly by the customers request.
Locally, the electrical supply houses have numerous programs to assist with lighting layouts,.
You might check with whomever is coming to supply the fixtures and see if they can't assist you and the customer with a suitable layout.

 

[skeshesh]

Check out the IEC handbook for recommendations of footcandle distributions. Also check local codes. Here in cali I pretty much follow the title 24 recommendations all the time, since a permit is required often and the footcandle calcs are sometimes a pain. It's a good idea to get used to design with some restrictive parameters since everything's moving in the direction of power consumptions reduction/effeciency with title 24, LEED certifications, etc.

 

[raider1]

In addition to what Gus posted, I would like to mention that not all commercial buildings are the same when it comes to lighting allowances and requirements.

The energy codes will give you a maximum wattage per foot allowance for lighting in a typical type of occupancy and they can vary depending on occupany and use classifications.

Chris