(CRI) COLOR RENDERING INDEX-
Color rendering is the ability of a light source to expose the color
of an object that it is illuminating. The CRI is expressed in terms
of a percentage between 0-100%. A light source that rates a 100%
CRI indicates that the color of the object being illuminated under
the light is as exposed as it would be at 12:00pm midday at the
equator at the time of the equinox on a clear day. An average incandescent
lamp carries a CRI rating of 98%, a common fluorescent 62% and a
typical streetlight 28%.
COLOR TEMPERATURE- The overall
color appearance of the light itself is its Color Temperature. When
referring to a source as either "warm" or "cool",
the Color Temperature is expressed in units of degrees Kelvin. Lamps
range from 2700-7500 degrees kelvin. Lower color temperatures (3000K)
represents a "warm" light. Higher (5000K) represents a
"cool" light.
(KWH) KILOWATT HOUR - The measure
of electrical energy from which electricity billing is determined.
A Kilowatt is 1,000 watts. One Kilowatt hour is indicative of the
use of 1,000 watts in one hour by an electrical device. As an example,
a 1,000 watt lamp will burn 1 kilowatt in 1 hour of use. A 100 watt
lamp burning for 1 hour will burn .1 kilowatts and if you pay $.08
per kilowatt it will cost you $.08 to run the lamp for that hour.
There are 8,760 hours in a year. Therefore to burn a 100 watt lightbulb
24 hours a day for 1 year will cost approximately $70.08. Energy
consumption is the single largest cost of owning and operating a
light bulb.
LUMENS - The unit of measure for
the light energy which flows in air, or in other words, the measure
of how much light a bulb produces. The total light output from electrical
sources is expressed in LUMENS PER WATT (LPW).
(LPW) LUMENS PER WATT - A measure
of the efficacy(efficiency) of a light source in terms of the light
produced for the power consumed. For example, a 100 watt lamp producing
1750 lumens gives 17.5(LPW) lumens per watt.
WATT - Unit used to measure power
consumption of a lamp. Watts = Volts x Amps.
