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Subject:
LED/Fluorescent comparison data *PIC*

Bill Tindall, E.Tn.
When you go to the store and buy a light for the shop you are buying a lamp that generates the light and a fixture to both power the lamp and direct light from the lamp to the work area. You want to get the most light on your work area for the dollar and you may want to have this light be of high quality (CRI) and a particular temperature.

I examined T12 fluorescent lamps and found a wide variation in output and quality-2250 lumens(lu) per lamp for GE Sunshine to 3600 lu for GE SPX 35, CRI’s of 70 for cheap shop lights to over 90 for quality lamps, and color temperatures from 3000 to 6000K. The more modern T8 lamps have a tighter range of output and quality and the same color temperatures- CRI of 80 to 90 and output clustering around 2900 lu.

Just considering lumen output fluorescent lamps can provide more light per fixture. However the ability of the fixture to direct light to the work area varies widely.

First some definitions going from cheapest to most sophisticated

Strip- has no reflector

Wrap- modest reflector

Troffer- designed fixture to direct light down and spread

High Bay These fixtures are designed to mount high in warehouses and the like and efficiently direct light down to the work area. )

I measured the light 4’ from various fixtures, simulating the bench surface with lighting 4’ overhead.

4’ 2 lamp fluorescent equivalent lights

FIXTURE Lumen Output Foot Candles at 4’ distance
Strip T12 6400 22
Wrap T12 6400 35
Lowes LED 4000 50
Max LED 4100 45
Quality LED 4800 70
High Bay 10,000 140

4’ 4 fluorescent lamp equivalents

T8 Troffer 11,000 105
Quality LED wrap 7900 100
LED Toffer 5000 95
High Bay T5 20,000 300
There are LED high bay fixtures but I was unable to measure one.

Conclusions

Quality LED fixtures offer as much or more light than most T12 or T8 fluorescent fixtures. Quality LED lamps can offer equivalent color temperature and CRI as fluorescent.

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LED/Fluorescent comparison data *PIC*
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