Brennan Homes Blog

Not too long ago when we needed a new light bulb it was a very simple process—just pick the incandescent bulb in the style and wattage that you desired. Today it is not that simple. There are many more choices than the good old incandescent bulb. Several years ago the CFL (Compact Fluorescent Light) bulbs appeared producing similar light but using much less electricity. But now in the past few years LED (Light Emitting Diodes) bulbs have appeared promising even more light and using even less electricity. There are five important factors to consider when selecting the correct light bulb:

1. Heat: Incandescent bulbs produce substantially more heat than either CFL or LED bulbs. As a matter of fact most of the energy used by an incandescent bulb generates heat instead of light. A CFL bulb produces less heat but still more than an LED. Tests have shown that a 100W incandescent bulb reaches a temperature over 325° F, a comparable CFL reaches over 175° F, and a comparable LED reaches only slightly over 85° F. So depending on the application if heat, fire hazard or safety is an issue a bulb that produces less heat could be desirable.

2. Brightness and Efficacy: Brightness of a bulb is measured in lumens (lm). A traditional 75W incandescent bulb outputs between 900 and 1000 lumens, a 13W CFL outputs approximately 800 lumens and a 10W LED outputs approximately 850 lumens. This translates into efficiencies of approximately 14lm/W for incandescent, 65lm/W for CFL and 85lm/W for LED. The higher this efficiency the less energy is used to produce the same amount of light.

3. Color: Incandescent bulbs have historically been known for their warm tones, leaning towards the red/orange of the color spectrum, CFL bulbs produce a relatively complete spectrum of light but have serious peaks at different points which results in color distortion; often why CFL is not the best choice for picking out clothing or other color sensitive applications occur. LED bulbs produce a light spectrum similar to incandescent and are also available in different “color temperatures” for different applications. Cooler color temperatures like 5000K will produce light more like natural sunlight. Whereas warmer temperatures like 3000K will produce light more like incandescent bulbs.

4. Average Life: The average life of a bulb is important because even if a bulb costs more but outlasts its competitors it could save money over the life of the bulb. The average life span of an incandescent bulb is 750 hours, a CFL is 8000 hours and an LED is 50,000 hours. This means that you could replace an incandescent bulb 67 times before you would have to change an LED once. This is important both with respect to the cost of the bulb and also the difficulty of the bulb to change. Bulbs located in two-story areas or tall entry fixtures could be difficult and costly to change.

5. Environmental Impact: The fewer bulbs are thrown away the less impact to the environment. So LED and CFL have advantages here. But CFL bulbs also contain mercury and emit greenhouse gases when disposed of; making them more harmful to the environment.

Between the cost of electric and the cost of the bulbs, an LED bulb could save over $6 per year compared to an incandescent bulb. By replacing only 20 bulbs in your house the savings over a 20 year period could be in excess of $2400. Try them in a few lights and see what you think.

~the Brennans