The brightness of an electric light is measured in lumens. A 60 watt incandescent light bulb has a brightness of 800 lumens. The efficiency of an electric light is measured in lumens per watt. Incandescent light bulbs have an efficiency
LED Lights

The brightness of an electric light is measured in lumens. A 60 watt incandescent light bulb has a brightness of 800 lumens. The efficiency of an electric light is measured in lumens per watt. Incandescent light bulbs have an efficiency
The central heating in my shared house is controlled by a white plastic box on the wall. This winter it broke down. I spent several hours downloading the 20 page manual from the internet and reading it. So far I