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 popo619 05-10-2013 06:31 PM

General question about cost/energy use of additional lightbulbs to a ceiling light

Hi.
When I talk about the light, i am referring to a regular bedroom ceiling light that you would flick on with a switch on the wall.
I was wondering if someone could explain if there is a difference in price and energy used when you add a lightbulb to a ceiling light fixture that can input at most 3 light bulbs.

So if i originally had 1 light bulb in place and didn't use the other two spaces, would it be cheaper then having 2 light bulb's in place, leaving the third space unused.

Here's a sample picture.https://www.google.ca/search?q=ceili...-6%3B894%3B894
A detailed explaination would be appreciated

EDIT:When I talk about the light, i am referring to a regular bedroom ceiling light that you would flick on with a switch on the wall.

 MTN REMODEL LLC 05-10-2013 06:45 PM

I don't work or pay attention to the POCO.... but yes... as a "rough" guess
one light bulb costs about 1/3 the cost of three, 2 light bulbs cost about 2/3 the cost of 3, and three lightbulbs cost exactly 3/3 of three light bulbs.

(generally for lights seldom used, the cost is relatively nominal/small.... but everything adds up, and CFL's and
LED's cost significantly less than standard incadesents EDIT;to operate.)

PS: I am a CPA and pretty sure of my answer.

 jbfan 05-10-2013 07:01 PM

Of course 1 lamp will use less energy of 2 lamps, as long as they are rated the same wattage, and 2 will use energy than 3.
The difference on the electric bill will be negligible.

 MTN REMODEL LLC 05-10-2013 07:26 PM

Quote:
 Originally Posted by jbfan (Post 1176740) Of course 1 lamp will use less energy of 2 lamps, as long as they are rated the same wattage, and 2 will use energy than 3. The difference on the electric bill will be negligible.
JB.... wasn't gonna get that technical... nor factor in the inherent heating factor/air conditioning variables as to final cost.:)

 popo619 05-10-2013 11:28 PM

thanks a lot guys

 ddawg16 05-11-2013 05:09 AM

It's a pretty simple thing to calculate.....

Look at the bulb wattage....actual wattage.

If you have a 65w bulb....if it's incandescent...it will put out 65 watts of heat energy....give or take a watt or two. If you have a 23w CFL...it will put out 23 watts of heat energy....give or take a watt or two....but...it will put out as much light as a 100w incandescent bulb.....

If you put 3 60w bulbs in a light fixture....you will have the equivalent of 180 watts of heat energy.

Simple math

Or put it this way....each watt of electrical energy a bulb uses is equal to 3.4 BTU's of heat. So a 100w bulb is going to give you 341.24 BTU's

 Minus08 05-11-2013 08:33 AM

Quote:
 Originally Posted by popo619 (Post 1176719) Hi. I was wondering if someone could explain if there is a difference in price and energy used when you add a lightbulb to a ceiling light fixture that can input at most 3 light bulbs. So if i originally had 1 light bulb in place and didn't use the other two spaces, would it be cheaper then having 2 light bulb's in place, leaving the third space unused.

Did you really ask if it is cheaper to burn one light bulb as compared to two light bulbs? Wow:whistling2::whistling2:

If I only drink one 12oz can of beer will I have less beer in my body than if I drink two 12oz cans of beer?

 Jim Port 05-11-2013 10:18 AM

I don't know if someone was trolling or is this a sad commentary on the educational system. Is 1<2<3? :(

 MTN REMODEL LLC 05-11-2013 10:58 AM

Quote:
 Originally Posted by Jim Port (Post 1177035) I don't know if someone was trolling or is this a sad commentary on the educational system. Is 1<2<3? :(
Jim.... You know I was thinking the very same thing when I ever answered the lady.... I wasn't sure.... and answered a little facetiously, although not too outlandishly.

I'm afraid it wasn't a troll.:(

Peter

 Speedy Petey 05-11-2013 11:34 AM

I have come to realize there definitely are people in our society that know absolutely nothing about electricity, how it works or how it is billed/costs.

Yes, leaving one light bulb out of a three lamp fixture will use less than all three, provided the wattage of those lamps is the same. Thing is wattage comes into play. Using two 60's in place of three 40's will obviously be exactly the same light and wattage used.

So simply asking if leaving one light out of three will save you anything, the answer is there is no answer.
Even so, leaving one 60W bulb out in a 3-lamp fixture will save you so much over the course of a year that you MIGHT be able to buy one of those beers Minus was talking about. By this I mean at the beer distributor buying them buy the 30-pack. NOT buying one at a major league ball game.

 MTN REMODEL LLC 05-11-2013 11:55 AM

Quote:
 Originally Posted by Speedy Petey (Post 1177070) I have come to realize there definitely are people in our society that know absolutely nothing about electricity, how it works or how it is billed/costs. Yes, leaving one light bulb out of a three lamp fixture will use less than all three, provided the wattage of those lamps is the same. Thing is wattage comes into play. Using two 60's in place of three 40's will obviously be exactly the same light and wattage used. So simply asking if leaving one light out of three will save you anything, the answer is there is no answer. Even so, leaving one 60W bulb out in a 3-lamp fixture will save you so much over the course of a year that you MIGHT be able to buy one of those beers Minus was talking about. By this I mean at the beer distributor buying them buy the 30-pack. NOT buying one at a major league ball game.

Speedy.... or you could drink the crap I do.... and get three.:thumbsup:

Peter

 RWolff 05-11-2013 01:05 PM

I am switching over to the Cree LED bulbs after reading some great reviews and testing results on them, I bought 4 last week for the two front pendant lamps at my gallery which are left on all the time, they are 60 watt equiv and use 9.5 watts each, shaped like an incandescent bulb they are for all intents and purposes indestinguishable from incandescents.
They also come with a 10 year warrantee.
I shopped around and found them at Home Depot for only \$12.97 (Amazon's lowest price was \$18) and with a \$45 total order there is free shipping, so I bought 4 to get the free shipping.

The two lamps take 3 bulbs each but I only put 2 in, that's 36 watts for the 4 bulbs, v/s the CFL's I had in them which used 26 watts each, it's easy to do the math 26 x 2 (I only had one CFL in each) is 52 watts, now I have 4 LED bulbs putting out 240 watts of light using only 36 watts of power, saving 16 watts in the process.
Were I to put 4 incandescent bulbs in, 60 watts x 4= 240 watts used per hour instead of 36, a big difference!

Realistically, lights don't use much or add much to an electric bill, it's all the other stuff that runs it up- the water heater, furnace, baseboard heaters, dishwasher, clothes dryer, fridge, A/C.
I pay 7.5 cents a kwh, the saving of 16 watts is miniscule, but I got the LED bulbs for reasons other than to reduce total wattage use, the lower power use is just a side bonus.

 Oso954 05-11-2013 02:06 PM

Quote:
 Realistically, lights don't use much or add much to an electric bill,
Not in your case, because you picked up most of the savings when you switched to CFL.

There are still a lot of people running incandescent bulbs that could benefit by switching bulbs to more efficient bulbs.

 joed 05-11-2013 02:18 PM

It depends. It's all about the watts(the real watts not the equivalent watts of CFL). If the total watts of the new two bulbs is more than the watts of the single bulb then it will use more power. If the total watts is less than the one bulb then it will use less power.
If you put in another light bulb the same size as the first one it will use twice the electricity. If you remove the first light bulb and install two bulbs with half the wattage of the one you removed it should use the same amount of power as one light bulb that was removed.

 bcgfdc3 05-11-2013 03:35 PM

Okay, So I understand the simplicity of the OP's question but I have a similar question.

Say I have a 4 tube 48" flourescent fixture. Is it cheaper to only put 2 tubes in or does it use the same amount because the ballast is still trying to power the missing tubes? I understand it will be less due to the actual wattage of the tubes not being there but dose the ballast use electric trying to power the missing tubes? Also, will this damage the ballast?

Thanks,
Rick

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