Shedding Light on the Right Bulb Choice

E26 Standard/Medium Edison Screw Base Lamps

I think light is the most overlooked and misunderstood aspect of interior design. Notice I didn’t say “lighting”, which is more about the fixture or luminaire (layman’s term: lamp) and the lamp (layman’s term: bulb) and how they’re applied. A bit confusing perhaps, but regardless of what you use and what you call it the end result is light. And light is what I am focusing on here as everything is affected by the quality and color of light in our surroundings. Unlike a chair or table, fixtures contain replaceable parts that can be chosen to suit your needs (if you know what they are). If you’ve ever tried to buy a replacement lamp, you know there is an overwhelming array of choices: size, base, wattage, glass type, color and technology. Unfortunately, most tend to replace the burnt lamp with something similar, convenient and inexpensive passing up an opportunity to improve your interior space. 

The three lamps shown above (incandescent, fluorescent and LED all with the same screw base) represent a slow and confusing evolution in lighting. They’re by no means the only sources available, but as you can see they’re all designed to replace one another as we move from left to right and towards higher energy efficiency in the home and work place.

LEFT: Incandescent lamps date from the 1880s and are basically a thin, coiled metal wire through which electricity flows. This results in about 2% of the energy being converted to light and about 98% to waste heat which is why governments are trying to phase them out of production. They give off a slightly yellow glow which is pleasing yet can distort paint and furniture colors. White walls that look cool blue in daylight look warm yellow at night. Halogen incandescent lamps offer an improvement in color (give off whiter light) and efficiency, yet still produce abundant heat.

MIDDLE: Fluorescent lamps (dating from the 1930’s) use electricity to excite atoms of mercury inside a glass tube. The excited atoms give off invisible UV light which then hits a phosphor coating inside the glass. The phosphor then glows visible white. Although fluorescent light has improved from the original green-blue-ish glow, food and faces can look flat and uninspiring when lit by these sources. You have to look hard and spend a lot to find high quality lamps that yield pleasing light. The newer coiled lamps shown above (compact fluorescent lamps or CFLs) are similar in size to the incandescent they’re trying to replace, are only about 10% efficient but they last 10-20x longer.  Unfortunately, they still cost 3-10x more than incandescent, take minutes to reach full brightness and are not convenient to dispose of or clean up when they break.

RIGHT: The last lamp is still in its infancy. The LED (light emitting diode) lamp is the holy grail of sources as their lifetime is measured in decades. Efficiency is marginally better than fluorescents, yet there are still issues with producing sufficient light compared to an equivalent sized incandescent lamp. The actual LED source or chip, about the size of a grain of salt, gives off modest light requiring several dozen grouped together in a single bulb for practicality. Surprisingly these devices do produce a lot of heat, not through a glowing coiled wire, but rather in a process similar to how the microprocessor in your laptop heats up. LEDs are widely used for specialty applications (indicator lights, computer and TV screens, and decorative lighting) but have a way to develop before they can be mass-produced for home use. Cost is prohibitively high ($75+) and there is no set standard for the form factor and appearance of the lamp. In the past several years LED lamps have been making strides but perhaps another 3-5 years before they’re at the usability level of compact fluorescents. 

So, what conclusions can be drawn? Newer technologies yield longer lifetimes yet have proportionally higher costs and less standard shapes. Total amount of light and color output is still not perfected compared to incandescent sources. So for the average home, incandescent still has a general advantage with CFLs best used in specific applications.

Personally, I try to specify slightly more expensive halogen incandescent bulbs whenever possible as they give off brighter, whiter light with better efficiently. I also use a lot of linear (2, 3 and 4’ long tube) fluorescent fixtures with a warm color output. They’re great for kitchen and bath as well as cove and soffit features. I would rather use CFLs for closets, basements and sealed bathroom fixtures instead of in table and floor lamps. LEDs are an expensive product better left for early adopters or those willing to experiment. I might recommend spending the difference in cost on a better quality fixture using a traditional lamp.

So what should you buy? It depends on your current fixtures and your conscience. Consider not only the potential energy saved but the cost of the lamp and frequency of replacement when choosing. Experiment and where possible use dimmers (they save even more energy and allow you to change the mood and appearance of a room). Have a question about lighting or are interested in more details? Just ask in the comment section.

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