Software for calculating foot candles

[Ravenvalor]

Hello,

I have been studying this on and off for a couple of weeks now. Does anyone know how many foot candles a 2 x 4 LED troffer emitting 4300 lumens ('Daybrite' model 2TG43L850-4-FS-UNV) will give an object at 5' distance using a 10% dimmer and a 1% dimmer?

The room dimensions are
-----------------------------
8' CEILING HEIGHT
3' WORKING HEIGHT
12' X 12' ROOM DIMENSION
WHITE LAYIN CEILING TILES
WHITE WALLS
GRAY PAINTED CONCRETE WALLS

The customer needs to be able to dim the light down to 5 foot candles, then up to 30 foot candles and then up to 50 foot candles.

Thanks for the friendly advice.

 

[jumper]

Cheap light meter or there various apps one download for smart phones.

 

[mgookin]

Hello,

I have been studying this on and off for a couple of weeks now. Does anyone know how many foot candles a 2 x 4 LED troffer emitting 4300 lumens ('Daybrite' model 2TG43L850-4-FS-UNV) will give an object at 5' distance using a 10% dimmer and a 1% dimmer?

The room dimensions are
-----------------------------
8' CEILING HEIGHT
3' WORKING HEIGHT
12' X 12' ROOM DIMENSION
WHITE LAYIN CEILING TILES
WHITE WALLS
GRAY PAINTED CONCRETE WALLS

The customer needs to be able to dim the light down to 5 foot candles, then up to 30 foot candles and then up to 50 foot candles.

Thanks for the friendly advice.

The manufacturer should have support available to help you with that. There probably is someone out there other than them who could figure it out but I'd go to the manufacturer for the most reliable (and free) source.

 

[Ravenvalor]

Thanks

Thanks

The manufacturer should have support available to help you with that. There probably is someone out there other than them who could figure it out but I'd go to the manufacturer for the most reliable (and free) source.

Day-Brite who is owned by Philips helped me out with this. They chose 2 - 54 watt LED troffers, (850s - CRI and Kelvin), and a 10% dimmer. This will get the foot candles down to about 3 and up to about 50.

Thanks for the help....

 

[gadfly56]

Day-Brite who is owned by Philips helped me out with this. They chose 2 - 54 watt LED troffers, (850s - CRI and Kelvin), and a 10% dimmer. This will get the foot candles down to about 3 and up to about 50.

Thanks for the help....

Careful about going below the 5 fc limit. I don't know what your application is, but the minimum illumination at foot-level for an egress path is 5 fc.

 

[Ravenvalor]

Careful about going below the 5 fc limit. I don't know what your application is, but the minimum illumination at foot-level for an egress path is 5 fc.

Thanks for the heads up. This is actually in a room where birds live. They try to simulate normal sunlight exposure. Dim lights in the morning and afternoon and bright lights around midday.

 

[Fitzdrew516]

I would suggest running the calculations with software and the fixture's actual ies file. You could run 2 different led 2x4's that put out the same amount of lumens and the FC levels could be completely different. Beam angle, relectors, etc. all make a big difference.

 

[david luchini]

but the minimum illumination at foot-level for an egress path is 5 fc.

What code requires a 5fc min? The IBC and NFPA 101 both specify a 1 fc minimum, though NFPA 101 says 10fc minimum for stairs.

 

[gadfly56]

What code requires a 5fc min? The IBC and NFPA 101 both specify a 1 fc minimum, though NFPA 101 says 10fc minimum for stairs.

I'll have to hunt around. Many years ago I worked for Hercules in Kenvil and the plant was a 24/7 operation (usually). I remember there was a project to upgrade the illumination on the walkways between the buildings. The quoted standard was 5 fc minimum. I can't recall the source; it's been over 25 years.

 

[Ravenvalor]

What code requires a 5fc min? The IBC and NFPA 101 both specify a 1 fc minimum, though NFPA 101 says 10fc minimum for stairs.

This application is for a 12 x 12 room used for raising and studying birds.

My lighting rep sent my requirements to Daybrite and they recommended two 54 watt troffers for this application.
2TG54L850-4-FS-02F-UNV-DIM

Thanks for the great input...

 

[jcbabb]

http://www.visual-3d.com/tools/interior/

This is what I use on a regular basis for simple quick and easy calcs. You will need the IES file from the manufacturer (easily obtainable from the website in general). For dimming, just adjust the calculate foot-candles accordingly.

 

[Barbqranch]

 

[mgookin]

View attachment 13532

Now that's cool! :thumbsup:

 

[Motes]

This is the software that I regularly use at work. It is a free software from German lighting manufacturer Dial. You can import IES files from any manufacturer into the program and add them to your model. It takes a little getting used to, but you can produce some pretty good 3D designs.

http://www.dial.de/DIAL/en/dialux/download.html