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Cracking the Code

Buying Bulbs

We’ll be the first ones to admit that buying light bulbs can be tricky, especially when you’re not familiar with lighting terminology. There are literally thousands of different light bulbs out on the market so finding the correct one can be a bit like searching for a needle in a haystack. Why do we even need thousands of different light bulbs, am I right? But to be fair, each one serves a unique purpose even though it makes it a bit tougher for the consumer to find the right one. Because we know just a little bit about lighting, we thought we would provide you with a guide to fluorescent bulbs including the common codes used by manufacturers and what they mean to you.
Here are some things you need to know.


Sample Code: F32T8/741

The F stands for “fluorescent,” a type of bulb characterized by mercury vapor that produces visible light when electricity is conducted through its end pins. The number after the F can stand for either the nominal wattage of the lamp or the length of the bulb. In the case of the sample code, it stands for 32 watts. However, an F48T12 bulb would stand for 48” in length.

The T stands for tube since most fluorescent lamps comes in a tube shape. The number after the T stands for the diameter of the bulb in eighths of an inch. A T12 would be 12/8” in diameter while a T8 would be 8/8” or exactly one inch in diameter.

Other codes may have numbers or letters following the initial code:

WW= Warm White
WW= Warm White Deluxe
CW= Cool White
CWX= Cool White Deluxe
D= Daylight
DX= Daylight Deluxe
730= 3000K Color Temperature (700 series)
735= 3500K Color Temperature (700 series)
741= 4100K Color Temperature (700 series)
830= 3000K Color Temperature (800 series)
835= 3500K Color Temperature (800 series)
841= 4100K Color Temperature (800 series)
850= 5000K Color Temperature (800 series)
BLB= Black Light Blue
BL= Black Light
EW= Energy Saver
FC= Circular Bulb
U= U-Bent
HO= High Output
SHO= Super High Output
TL= Trim Line (Philips Trademark)
PLUS= Longer Life Hours