wasser_1@viking.DEC (John A. Wasser) (02/15/85)
Here is some lightbulb trivia gathered from the labels of G.E. 120V lightbulbs at some local stores (Price is based on the lower non-sale price from two stores): G.E. Rated Average Average Bulb Input Output Life Price Type Watts Lumens Hours Dollars ---------- ------ ------ ------ ------ Standard 100 1750 750 $0.85 Standard 75 1190 750 $0.85 Standard 60 870 1000 $0.85 Standard 40 505 1000 $0.85 Soft White 100 1710 750 $0.75 Soft White 75 1170 750 $0.75 Soft White 60 855 1000 $0.75 Soft White 40 490 1000 $0.75 Miser 95 1710 750 $0.95 Miser 70 1170 750 $0.95 Miser 55 855 1000 $0.95 Long Life 100 1585 1500 $1.50 Long Life 75 1075 1500 $1.50 Long Life 60 820 1500 $1.50 Clear Bulb 100 1750 750 $1.15 Clear Bulb 60 870 1000 $1.35 ---------- ------ ------ ------ ------ From these figures, I checked a number of "figures of merit". Here are the top five bulbs in each class: (Note: Cost of Screwing was ignored. Electrical costs are figured at $0.06 per KWH. The total electricity cost over the life of the bulb was generally around four times the price of the bulb) Power Efficiency (Lumens per Watt): (Use these if your electrical power is much greater then $.06/KWH ) Miser 95, Standard 100, Clear 100, Soft White 100, Miser 70 Cost/Light Efficiency (LumenHours per Dollar): (Use these if you want the most light for your dollar) Miser 95, Standard 100, Soft White 100, Clear 100, Long Life 100 Cost/Bulb Efficiency (Hours per Dollar): (Use these if you just want ANY amount of light no matter how dim) Soft White 40, Standard 40, Miser 55, Soft White 60, Standard 60 Conclusion: If you are a landlord who is providing light for somebody else, use low wattage bulbs because they provide the most bulb life for the dollar. If you want illumination, use high power bulbs because that are more power efficient and will cost less FOR THE SAME AMOUNT OF LIGHT. If you don't like to change lightbulbs (Cost of Screwing is high) choose the Long Life bulb in the appropriate wattage range... you loose little power efficiency for the additional life. -John A. Wasser Work address: ARPAnet: WASSER%VIKING.DEC@decwrl.ARPA Usenet: {allegra,Shasta,decvax}!decwrl!dec-rhea!dec-viking!wasser USPS: Digital Equipment Corp. Mail stop: LJO2/E4 30 Porter Rd Littleton, MA 01460