10/01/2011
Knowledge is Power:
Lighting Terms
Watts - refers to consumption of electricity, or the power that is used to operate a light source, e.g. light bulbs
When a light bulb with a power rating of 100W is turned on for one hour, the energy used is 100 watt-hours, 0.1 kilowatt-hour, or 360 kJ. This same amount of energy would light a 40-watt bulb for 2.5 hours, or a 50-watt bulb for 2 hours.
Volts - refers to electrical current.
Household current is at 110 volts. Most light bulbs are made to accept 120 volts of incoming power to allow protection from fluctuations in the incoming voltage. 130 volt bulbs will have a slightly longer life span but tend to burn dimmer due to the fact that they are receiving only a 110 volt input and thereby operate at less than 100% of their efficiency.
Lumens - refers to light output or brightness
Sunlight on average ranges from 32,000 to 100,000 lux, or lumens per square meter. A flourescent bulb can produce between 50 to 100 lumens per watt, compared to an incandescent bulb which maybe produces 15 lumens per watt.
Resources:
en.wikipedia.org
haciendalighting.net
ehow.com
howstuffworks.com
