Tips and practical examples to reduce the cost of lighting without decreasing brightness, or change habits
Lighting accounts for 15-20% on your electricity bill of every family. But few are aware that the expenditure can be easily reduced to a quarter without changing habits and at constant luminosity inside.
The solution is very simple, it is enough to replace incandescent lamps with more energy efficient ones. Let's do some calculations. The energy-saving lamps have a higher initial cost but also allow considerable savings on your bill. The initial price is, therefore, depreciate in a short time. They last longer. A fluorescent lamp has an average life of 8000 hours, eight times greater than a normal incandescent lamp. Are more efficient. Became light 20% of electricity compared to 4% of traditional incandescent lamps. In other words, an old bulb dissipates 96% of the electricity into heat and only 4% to illuminate a room, conversely a fluorescent lamp of the same wattage lights five times more than the same consumption.
What has changed on the bill? Simply that an energy saving bulb produces the same light as an incandescent while consuming less electricity. An energy saving lamp 20W delivers the same light as a 100W incandescent bulb. In terms of brightness of an incandescent lamp produces an average of 10 lumens / Watt, unit of measure for measuring the brightness, while a compact fluorescent lamp fluctuates around 50 lumens / watt.
The energy-saving lamps have a higher initial price. If an incandescent bulb is sold at a price less than one euro, for an energy-saving lamp the price fluctuates around ten euro. Many consumers perceive only this difference in initial price without considering the actual savings in electricity bills.
Let's take an example. A 20-watt fluorescent lamp produces a brightness of 1000 lumens, has an average life of 8,000 hours, and an average purchase price of € 10. During his entire life consumes 160 kW / h (20 watts x 8000 hours = 160,000 Watt / h). Considering the average cost of 0.16 € / kWh spending in the bill is € 25.6. Adding the purchase price (10 Euros) with the consumption eight thousand hours (€ 25.6), we obtain a total expenditure of € 35.6.
We would have paid with an incandescent lamp? In the first place the incandescent lamp has a shorter duration, on average 1,000 hours. So to brighten up 8000 hours as in the previous case, we will buy eight o'clock. Considering a purchase price of a light bulb to € 0.50 the total cost of purchase rises to 4 € (0.50 € x 8). Secondly, to obtain a brightness of 1000 lumens have to buy an incandescent lamp with a power of 100W and therefore with a higher consumption of electrical energy. At 8000 hours incandescent lamps consume 800 kW / h (8,000 hours x 100 W = 800,000 Watt / h). Considering the average cost of 0.16 € / kWh consumption is equivalent to a spending bill of 128 euro. Adding up the cost of buying (4 euro) with the variable cost of consumables (€ 128), we obtain the total cost of 132 Euros.
In conclusion, brighten up a room for 8,000 hours (about 4-5 hours a day for 5 years) can cost 132 Euros with incandescent lamps or fluorescent lamps with 35 Euros in energy savings equal to saving 73% of the spending lighting.
Fluorescent lamp
A fluorescent lamp bases its operation on the electrical discharge between two electrodes placed at the ends of the lamp. These discharges excite mercury vapor content at low pressure in the lamp causing it to emit ultraviolet light, and thanks to the presence of fluorescent powder on the inner lining. These lamps are more energy-efficient. The system of fluorescence allows you to transform into light as much as 20% of electricity used. To have a meter in comparison just think that an old incandescent light bulb was able to convert light only 4% of the electricity consumed. Another big advantage of fluorescent lamps is their long duration, on average 8,000 hours of use against 1,000 of the old incandescent or halogen lamps to 2,000.
What are fluorescent lamps on the market? Initially they were put into commercial fluorescent lamps halophosphate, then the exit of the model to overcome Triphosphor able to reduce the presence of mercury in the lamp to 5 mg and ensure a greater brightness concentrating the radiation in the three colors present in nature: red, green and blue. The tri-phosphor fluorescent lamps also have a longer life, 12,000 hours of use.
10/12/2012
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Translated via software
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Source:
Italian version of ReteIngegneri.it