Spiral Fluorescents or T-12's , cost and efficency question
I just bought a 6 pack 60 watt spiral fluorescents from Home Depot for 10 bucks.
These are rated as a 60 watt equivalent..I assume that they are comparing it to a standard incandesant bulb. That incandesant was costing me $ 3.08 to run 24/7 for one month and these cost .67 per month. So the cost savings for the house fixtures is a no brainer. The 4 foot T-12 fluorescents cost $ 1.91 to run 24/7 for one month. ( FYI figures taken from Ameron US light calc cost estimator) They appear to be flat out daily cost winners.
The spiral is listed as 900 lumens, color 2700K, 14 watts, 10,000 life hrs.
The T12 (cool white) is listed as 3150 lumens, color 4100K, 40 watts, 15,000 life hours.
Spiral gets 64.28 lumens per watt while the T-12 gets 78.75 lumens per watt.
Six spirals cost $ 10. and $ 3.91/month to operate and emit 5400 Lumens.
Two T-12's cost anywhere from $ 2.50/each up to $ 6.00 and would cost $ 3.83/ month to operate and would emit 6300 lumens.
With all of that being said there isn't a large difference here except the color and the cost of the fixtures to hold the bulbs. I happen to own many clamp on fixtures from a lucky garage sale grab. So I have the power to run either.Maybe the solution is to mix em up and use both?