Real Estate

Handy Hardware: Lightbulb basics

Temperature, direction and type play role in right bulb for your space

If you are reading this indoors, chances are a lightbulb is illuminating the page. What type of light being emitted all depend on some lightbulb basics: temperature, direction and type.

The first factor determines the room's glow. It can range from stark blue to cozy orange, all depending on temperature. Kelvin range factors in when buying bulbs because it determines the light color, says Geoffrey Davis, a salesman at Stanford Electric Works in Mountain View.

Many homeowners, he says, come in asking for a warm, daylight feel when it comes to new lighting. But in actuality, daylight is a very white light source that measures in at nearly 6,500 Kelvin. For comparison, warm light ranges from 2,700-3,000 Kelvin and standard light falls at about 3,500 Kelvin. At 4,100 and up, people will tend to view the light as blue/white.

"In general, you want to look for lower levels for the yellow, warm light," Davis says.

To get the most of the cool or warm light, users should next check the beam spread of the lightbulb.

"You want light shooting in all directions," Davis says.

This is achieved with omni-directional bulbs. With these bulbs, owners will avoid weird effects on the walls, especially when used in lamps, he says.

Lastly, technology and cost help determine the type of lightbulb used. Options range from LED lighting to incandescent.

"If you have a chance to get the LEDs, they are the best," Davis says.

LEDs last 25 times longer and use at least 75 percent less energy than incandescent lights, according to the U.S. Department of Energy. Davis also adds that LEDS give off comparable light to their incandescent counterparts during their 25,000-50,000 hours of use. A downfall is the additional upfront cost.

Incandescents on the other hand are cheaper, but range from 1,000 to 2,000 hours of use.

Fluorescent lighting falls somewhere in between on the hour rating at 10,000. The option, while more energy efficient than an incandescent, can take about two minutes to heat up to full brightness and contains mercury, which requires special recycling, Davis says.

If the light in your fixture goes out, and you are just looking to replace it, Davis offers a rule of thumb:

• 100-watt incandescent bulb equals 1,600 lumens

• 75-watt incandescent bulb equals 1,200 lumens

• 60-watt incandescent bulb equals 800 lumens

With these factors in mind, bulb buyers are prepared to make the right light purchase.


Correction: The Fall Home + Garden Design story, "Lightbulb basics," incorrectly stated the measurement unit for light color, which is Kelvin. It has been updated. The Weekly regrets the error.

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