- Light Output
- Both bulbs put out similar light output although the T8 puts out slightly more light, although the difference is not noticeable to the human eye. According to Philips, a maker of light bulbs and lighting equipment, a T8 bulb produce around 2600 lumens (the unit used to measure light output) while the T12 bulb puts out around 2520 lumens.
Over time the bulbs begin to lose their intensity and brightness. T8 bulbs have a slower period of decrease, losing only 10 percent of their initial brightness after 7,000 hours of use. In comparison T12 bulbs can lose 20 percent or double the T8 lose after the same number of hours.
the reason for the question is the utility is trying to say that you get as much or more light from a 3 lamp t-8 light as you would from a 4 lamp t-12. I do not see how this is true because you are comparing 4 40 watt tubes with 3 28 or 32 watt tubes. The only difference I see is a reduction in power comsumption. I think that if I have 4 lamp fixtures now I need to stay with 4 lamp fixtures for replacement.