Incadescent cost vs CFL's

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jgarner

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Working on cost proposal for local resturant to change from 65 watt par 38 in recess lights to 11 watt cfl. Isn't there a formula to get a average cost to operate for a year? I'm thinking something like this. 65 X 14hrs a day, X 365 days a year equals 332,150/1000=332.15 X .09 cost per kilo watt=$29.89 a year to operate. A 11 watt cfl= 11X14 hrs X 365 days=56210/1000=56.21 X .09= $5.06 a year. Is this correct? Thanks.
 
jgarner said:
Working on cost proposal for local resturant to change from 65 watt par 38 in recess lights to 11 watt cfl. Isn't there a formula to get a average cost to operate for a year? I'm thinking something like this. 65 X 14hrs a day, X 365 days a year equals 332,150/1000=332.15 X .09 cost per kilo watt=$29.89 a year to operate. A 11 watt cfl= 11X14 hrs X 365 days=56210/1000=56.21 X .09= $5.06 a year. Is this correct? Thanks.
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I think your calculations are correct.
You might want to look at life expectancy of a CFL in a recessed light fixture.
 
A 60 watt bgulb give off about 800 lumens. An 11 watt cfl only gives of 360 lumens. Depending on what you are lighting, you may need to use a 15 watt to get the same lumen output that you have now.
 
Waiting for the NEC code to catch up with this issue! Measuring watts per square foot per 220.12 doesn't really make sense in this day and age. In regard to lighting, the area should be a lumen count per square foot, rather than a watt. It's like comparing apples to oranges.

Anyone know of any 2011 Code update in this area?
 
Rockyd said:
Waiting for the NEC code to catch up with this issue! Measuring watts per square foot per 220.12 doesn't really make sense in this day and age. In regard to lighting, the area should be a lumen count per square foot, rather than a watt. It's like comparing apples to oranges.

Anyone know of any 2011 Code update in this area?
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General purpose receptacle outlets also are covered by 220.12. Unless a lamp is plugged into the receptacle outlet, it is hard to get lumens to come out of the thing. Perhaps the two should be seperate , lumens for lights and watts for the "plugs".
 
Energy costs are not the only factor when replacing incandescent lamps with CFLs. Especially when dealing with recessed "hi-hats" many of the CFLs won't last any longer than the BR-30's they replaced. :-?

With the much higher initial costs of the CFL's you may not be saving much at all, if this happens to you.:mad:
 
bob said:
A 60 watt bulb give off about 800 lumens. An 11 watt cfl only gives of 360 lumens. Depending on what you are lighting, you may need to use a 15 watt to get the same lumen output that you have now.
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I agree. You'll want a higher wattage CFL or the customer will not be happy with the result. No matter the energy savings. Does the restaurant dim the existing lights? Will you need dimming ballasts for these CFL lamps?
 
kbsparky said:
Energy costs are not the only factor when replacing incandescent lamps with CFLs. Especially when dealing with recessed "hi-hats" many of the CFLs won't last any longer than the BR-30's they replaced. :-?

With the much higher initial costs of the CFL's you may not be saving much at all, if this happens to you.:mad:
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$25 buys a lot of CFLs in a year.
 
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