A lighting company has recommended that my business switch our old 4 fixture fluorescent bulbs to the new smaller T8 ones. There are some tax credits involved that helps lower the price. However, the recommendation is to change all my old 4 lbulb fixtures (old style) to fixtures that have only two T8 bulbs. Supposedly the light with the T8 will be just as bright. Can this be true? I sure don't want to pay money to get less light even if it's more efficient!
Jim

Not so, T8 are slightly more bright but not noticeably to the human eye. Their advantage is being more efficient. If you switch from 4 T12 to 2 T8 bulbs you will be cutting your lumens by about 45% http://www.ehow.com/about_5426758_fluorescent-vs-bulbs.html

Bal is correct, there is no 4ft T8 lamp that gives the light output of two 4 ft T12 lamp.

There is a T5 HO lamp that will equal two 4 ft tT12 lamps.

Perhaps this is what is being offered?

Some of the "lighting" firms out there sell snake oil.

Ask for data sheets of both the existing lamps and the proposed lamps. Be sure these datasheets come from the lamp manufacturer, not some spreadsheet or hype sheet they produce.

The key to this equation is retro-fitting the fixture with a silver metallic reflector. If that is done properly, two T-8's will actually produce more light than 4 T-12's in a standard white fixture.

the key to this equation is retro-fitting the fixture with a silver metallic reflector. If that is done properly, two t-8's will actually produce more light than 4 t-12's in a standard white fixture.

Interesting