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| There are two varieties of T5 lamps. One runs 28 watts and puts out 2900 to 2950 lumens initially. Better efficiency than the 32 watt T8 that puts out the same light. These are values for nominal 4' lamps. The other T5 high intensity lamp is less efficient than the T8 but better than the T12. Big box stores may have the 28 watt T5 lamps and fixtures but tend to not have the high output T5. The old 40 watt T12 lamps put out around 4000 lumens, not at all bad but they use more mercury so are legally obsolete.
Fluorescent lamps start out with full output and gradually get weaker. But in most work environments they all loose output more rapidly from dust and grunge on the lamps and the reflectors. Regular cleaning will keep them brighter. That's needed more often in shops than offices and home, but ALL installations benefit from periodic cleaning.
The best lamp I know of for energy efficiency is the color corrected high pressure sodium vapor lamp. Trouble is it takes ten or 15 minutes to get to full intensity. Or to restart after a power glitch. It runs about twice the lumens per watt of HO fluorescent.
Gerald J. | |
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Lighting question? Different flourescent bulbs?
