Question by pink.love: I know fluorescent lighting is more energy efficient but how much energy is it saving?
What if all the fluorescent lights in a classroom were turned off, about how much money or energy would that actually save?
Best answer:
Answer by Jerry Lee
It will depend on the size of the classroom, and how well lit it is. It will require more lighting if it has dark paint or dark floors, or faces north, or they have classes at night, or there are no windows at all.
I estimate 1,000-2,000 Watts.
What do you think? Answer below!
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Use of fluorescent bulb over the old incandescent bulbs should give at least a 78% savings. I made this calculation from the wattage and lumen output compared to a 40 watt incandescent bulb. To calculate exactly it would require much more information.
Hey Pink, Jerry is pretty close on the power usage. To answer your question as directly as possible, my son is in 5th grade, and his classroom has three strips of lights, each one made up of five fixtures. Each fixture is 4 feet long and has 2 – 48inch tubes inside. This type of fixture generally uses 72watts with both tubes running. The total wattage for the room is 72 X 15 = 1,080 watts when all the lights are on. Flourescent lighting is about 4 times as efficient as incandescent lighting. To light that same room with old fashioned light bulbs would require over 4000 watts, so the power of flourescent lights is pretty easy to see.
Most schools pay a slightly reduced rate for electrical power, but still the amount varies quite a bit from state to state. In our town, a school should pay around 9 cents per kilowatt hour. A kilowatthour, or KWH is 1000 watts running for one hour. Let’s say the school is open for 8 hours, but the kids are only in the room for 6 of them. If the lights were on for 6 hours, it would use 6.5 KWH, at a cost of about 60 cents. So if the lights were off all day, it would save the school 60 cents each day. If they were only on for 3 hours each day instead of 6, it would save 30 cents each day of school, or about $6.00 per month. Again, this will vary school to school, and town to town, but the idea is the same.
If you’re in the education business, here is something you might be interested in. Look online for a device called a, “Kill – A – Watt,” meter. They cost around $35. They look like a lamp timer, but are really a load meter. Plug it into the wall, then plug any device with a cord you have laying around into the meter. It will tell you how many watts your device is using at the moment, and how many KWH’s it has used over time. Some models even let you punch in your utility rate, and it spits out how much your device has used in dollars and cents for as long as you have it plugged in. Now take a lamp and put in a 40 watt light bulb and run it on the meter, it will tell you it is using 40 watts. Next, change the bulb to a 15 watt compact flourescent one, it will register 15 watts, but ask the kids in the room which one is brighter, turns out they are about the same. It’s really interesting to see the lights literally come on in the room when you do experiments like this.
We live in a home that is powered by the wind and sun, and over time we’ve had to learn a great deal about energy savings. From time to time, we get to run a solar power seminar for the kids in the schools in our area, and this is one of the experiments we do. It’s also interesting to plug other items into the meter, like a radio, or a game system, so the kids can see how much they are using at home. There is a great magazine out that covers all this stuff, it’s not very common on news racks, it’s called Home Power. I will include the link below, and some other places you can google to find out lots of interesting info on renewable energy and energy savings. Take care Pink, Rudydoo
I am guessing you wanted to say “What if all the fluorescent lights in a classroom were turned on”. Well, it depends on the number of lights you have in the classroom, but as compared to the same number of older bulbs, you will save at least 60% on your electricity bill.