New Bulb Technology
For many years we have bought light bulbs for our homes based on the wattage shown on the box (60 watts, 100 watts, etc.) However, bulbs with new technology come into stores regularly showing reduced usage, so using watts for comparison is no longer the best way to buy your bulbs. It doesn’t tell you how bright the bulb will be, it only tells you how much electricity it will consume.
A better way to shop is to buy bulbs by lumens first. The amount of “lumens” tells how bright the bulb will be, and then you can look at watts to see how efficient it will be in saving on your utility bill.
So, you probably wonder what is the difference between a watt and a lumen.
What’s a Watt?
A watt is the power needed to move a one kilogram object at the speed of one meter per-second against a force of one newton. Since that definition make no sense to most of us, a better definition of a watt is the amount of electrical power a device consumes as it operates. Since you can buy multiple bulbs of the same wattage that will each give off a different amount of light, making a purchase based only on the wattage is a poor standard.
What’s a Lumen?
A lumen is the amount of visible light emitted by a source. Light sources usually also give off light that the human eye can’t see, but you don’t care about that when you are buying light bulbs. Lumens is a direct measurement of the light you can see, which is what you really care about. You can buy high-lumen bulbs (1700 or more) for reading areas or task lighting, and buy low-lumen bulbs (800 or less) for back lighting or atmosphere in a room.
Changing Your Habit
Comparing lumens should be the first standard to consider when you buy bulbs, so that you know you’ll get the degree of brightness that you want. Secondly, you should look at the type of bulb to see which fits best with your style of lamp or lighting fixture. Finally, look at the wattage to see how much it will cost you to use the bulb.
If you are getting the brightness you want and can reduce usage from 60 watts to 12 watts, that can add up to a big savings over time. Now get out there and buy some bulbs!