Lighting Calculation

[mtnelectrical]

Does any one know a website where I can find some simples formulas to calculate how much light is needed for small offices?, I am working on a project, owners wants 2x4 fluorescent lay in fixtures. Any help is always appreciated.

 

[celtic]

T220.3(A) says you need 3 1/2 VA /sq. ft. (Check note B)

How many sq,ft is the office
How many watts are the lamps

Done

 

[mtnelectrical]

It is a small office aprox 36'X20' by 9' high 4-4' 32w T8'

 

[growler]

It is a small office aprox 36'X20' by 9' high 4-4' 32w T8'

I use the ceiling grid lay out to figure the number of fixtures. I like for things to end up symmetrical. To do this I need the grid lay out.

You may also wish to concider the lay out of office furniture.

 

[mtnelectrical]

Do you use any program to do this Growler?

 

[growler]

Do you use any program to do this Growler?

No, because I have never seen a program that takes all factors into consideration. The color of the carpet or floor tiles will have an effect and so will paint color. The size of the customers wallet.

Unless you are going for the absolute minimun of light allowed then a program is not necessary.

The reason that I like to have the grid lay out is that lights are not the only thing going in the ceiling. The HVAC people have vents and there may be a sprinkler system. Can you put the lights where you want or is there a sprinkler pipe or AC duct in the way.

OK, does this 720 SQ. Ft of office space that you are talking about include a bath room or a seperate section ( office ) for the boss. Is there any sort of lay out or just open space.

What I do once I get the grid lay out is to mark the number of fixtures and present it to the owner /contractor if they are Ok with it ( normally) then I run with it, once the job is near completion if there is an area that needs more light then it can be done for an extra charge.

The real deciding factor normally end up to be the size of the customer's wallet.

 

[mtnelectrical]

Thanks Growler for your response. No it is only open space, Bath is another area. No ducts for A/c nor Sprinkler. The only thing owner wants is a well illuminated office for his salesmen.

 

[aline]

Does any one know a website where I can find some simples formulas to calculate how much light is needed for small offices?, I am working on a project, owners wants 2x4 fluorescent lay in fixtures. Any help is always appreciated.

Here's one. Google is your Friend.
http://www.gelighting.com/na/business_lighting/education_resources/tools_software/toolkit/layout.htm

Do a google search for lighting calculators and you will find more.

 

[Rewire]

I did a job that wanted a set amount of lumens/ft I called the lighting rep and he did all the calculations for me and gave me a layout.