09 Feb '07 22:071 edit

I am going to buy some bulbs for our cleanroom, 48 inch tubes, one lasts 20,000 hours, consumes 32 watts, costs $2.00 each.

The other lasts 24,000 hours, called the super miser, consumes 30 watts but costs three times as much, $6.00 each.

Power cost is $0.08 /Kwhr. If you have two cleanrooms with say, one hundred of these bulbs in each one, will there ever come a time when the more expensive bulb will start saving money? If so, how much time is that?

The other lasts 24,000 hours, called the super miser, consumes 30 watts but costs three times as much, $6.00 each.

Power cost is $0.08 /Kwhr. If you have two cleanrooms with say, one hundred of these bulbs in each one, will there ever come a time when the more expensive bulb will start saving money? If so, how much time is that?