It used to be so easy. The only question you had to answer when replacing a light bulb (lamp) was, "How many Watts?" But that was then. I'm here to save you a few minutes in the lamp aisle at the home store. Before your next trip, be armed with the answers to the following five questions:
1. How Bright?
Today we have to think in Lumens instead of Watts. An old 100 watt lamp produced about 1600 lumens. A 60 watt standard incandescent lamp is about 800 lumens, and 40 watt incandescent = about 450 lumens. Before you shop, know how bright you need the light to be - in lumens.
2. What Color?
Not all "white" light is the same color. For more on that topic, check out the pictures in this previous post. The point is that most of today's sources are available in different color temperatures. To most closely resemble incandescent light, select a warm hue, between 2500 and 2800 Kelvin.
3. Where Used?
This question really embodies lots of other questions. Is it in an enclosed fixture? Indoors or outside? In a transient space like a closet? Somewhere extremely hot or cold? Is it used to accent a piece of art, or does it need to be fairly shadow-free? Certain CFLs don't do well in winter temperatures, LEDs prefer the cold. Most LEDs aren't designed for fully enclosed fixtures. Many CFLs aren't either. CFLs generally take a little time to get fully bright, so they might not be the best choice for closets. LEDs tend to be very directional and better for accent lighting, but can be diffused for general lighting. CFLs are great for general shadowless illumination but are never very directional. Know where the new lamp will be used.
4. How Controlled?
Is the lamp you are replacing on a switch or a dimmer? If it is controlled with a dimmer, replacement options are more limited, and you should check dimmer compatibility before you purchase a replacement.
5. How Much Money?
Consider both initial cost and ongoing costs. To spend the least money today, buy an incandescent or halogen replacement lamp. In the long run, this choice will cost the most in energy and replacement lamps, even though the initial outlay is the smallest for this category. The middle of the road option is fluorescent. It will cost a little more today, but will last a little longer and save a little more energy than the traditional sources. Top of the line is LED. These still cost the most, but will provide the most light per watt and will last the longest...provided you buy a quality product and use it in an appropriate application.
If you head to your local light bulb store with the answers to these questions in mind, you should save yourself a few minutes. Maybe you'll even have enough time to browse the clearance aisle and get one of those inflatable snow globes at 75% off!