Over the last decade, LED (Light Emitting Diode) technology has advanced at light speed. In addition to their high-efficiency, low radiant heat and long source life, the progress is also giving us more options in their brightness and intensity, they are more resistant to shock and vibration and can be more easily controlled and programmed. I can personally appreciate having more color options being offered today as the blues in fluorescent lighting are not pleasant.
LED light sources are also gaining popularity due to the growing energy conservation movement. According to the U.S. Department Energy, no other lighting technology offers as much potential to save energy and enhance the quality of our building environments.
I thought a brief explanation of what you see on the LED bulb packaging might be helpful.
What is CRI?
CRI (color rendering index) is a scale from 0 to 100 percent indicating how accurate a “given” light source is at rendering color.
The higher the CRI, the better the color rendering ability. Light sources with a CRI of 85 to 90 are considered good at color rendering. Light sources with a CRI of 90 or higher are excellent at color rendering.
Example: A 2700K (“warm”) color temperature incandescent light source has a CRI of 100. A 5000K (“daylight”) color temperature fluorescent light source has a CRI of 75.
For an in-depth breakdown on HIGH CRI LIGHT BULBS and SPECTRAL POWER DISTRIBUTION go to Top Bulb.
Lumens are replacing watts. The lumen is a unit of measurement for the brightness of light. If a light bulb is blindingly bright, it produces a lot of lumens.
A typical light bulb in your home might produce about 1000 lumens. Lumen is related to the word luminous, which means “bright” or “radiant.”
The Kelvin temperature scale is a measurement of heat energy or temperature, which advances in the same increments. Simply put, the temperature is how cool or warm the light appears. Specific to lighting, Light color or, the tone of “white” emitted from the light source is measured.
Lower Kelvin numbers mean the light appears more yellow; higher Kelvin numbers mean the light is whiter or bluer.
• Warm colors are lower temps; 2,700-3000k
• For a whiter light, look for bulbs marked 3500-4100K.
• For bluer white light, look for bulbs marked 5000-6500K.
What does lifetime mean?
“Lifetime” is how long the LED will last. The old incandescent bulbs were good for about 750 to 2,000 hours. The new LEDs are tested against 50,000 to 100,000 hours of light based on design and operating temperature. LED lifetime means the period at which the LED only puts out 70% of its original light-not total failure. It does not mean your LED will suddenly go out like your filament bulbs that would pop and go black when you turned on the light switch. The LED will just become dimmer because it will emit less light. Heat does effect lifetime. The more heat generated for an enclosed LED product will mean less life. Even so, it will still offer tens of thousands of hours of light and not to worry, the temperature even in hotter conditions is extremely low compared to what we have experienced to date with other types of lamping. So no fire or safety danger from super hot bulbs.
Because lighting in the home plays such an important part, I hope this has added a better understanding for you when purchasing LED products at your local home improvement store.