How To Calculate Watts & Savings: CREE LED Cr 24 vs Fluorescent T12

Posted by Dave VanTol on Fri, Feb 10, 2012 @ 07:02 AM

What Is A Good Replacement For 2x4 T12 Fixtures?how-to-calculate-watts-cree-led-cr24

In a previous article I highlighted the benefit of the CREE LED 2x4 replacement fixture.  Today were going to compare the LED 2x4 to a standard T12 2x4.

T12 technology is going by the wayside. The federal government is accepting the T8 amp as the new standard......but that doesn't mean you don't have choices beyond fluorescent.

T12 2x4 vs. LED 2x4

Fluorescent T12

A standard T12 lamp has a life of 20,000 hours and a lumen output of around 2500 lumens.

The lumens per watt of T12 is roughly around 60 and a CRI of 70. Your average 2 lamp fixture will consume 90 watts, the 4 lamp version will consume roughly 160 - 170 watts depending on the ballast.

CREE LED Troffer

The CREE LED fixture has a MINIMUM rated life of 50,000 hours. It boasts a MINIMUM 90 lumens per watt with an option for 110.

The fixture is available in 4 light output levels but let's choose the 4000 lumen model that that produces 110 lumens per watt and only consumes a total of 36 watts and has a CRI of 90.

Comparing The Cost To Light Annually

Lets you have existing 2 lamp T12 fixtures in an office environment:

We have 100 total fixtures that run 11 hours a day at .11 cents per KWH.

T12 Fluorescent- 100 X 165 watts = 16,500W/1000 = 16.5 KW

16.5KW X 4016 annual hrs = 66,264 KWH yearly

66,264KWH X .11cents per KWH = $7,289.04 annually to run


CREE LED Troffer- 100 X 36 = 3600W/1000 = 3.6 KW

3.6KW X 4016 annual hrs. = 14,458 KWH yearly

14,458KWH X .11cents per KWH = $1590.38 annually to run. 

Savings = $5,698.66 per year

SEE The Difference In This CREE Video

I could go on but the video shows the difference! Curious yet? Contact us today and find out if LED is right for your business!


Topics: how to calculate watts, led 2x4, led troffer