Tag Archives: Kill-A-Watt

CFL energy efficiency environment how-to LED lighting science project

LED Bulbs vs. Compact Fluorescent: Part II

DSC_0662 I wanted to revisit an earlier post comparing LEDs, CFLs and traditional incandescent bulbs. I found two different values for the power and light output of the Lemnis Lighting Parox II bulbs, and same folks at work were wondering the same thing.

I decided to bust out my trusty Kill-A-Watt and see how much power the bulb was really drawing.

I watched the meter for a bit and it never went above 4 Watts. So that’s a bit of a bonus. Out of curiosity I decided to plug my CFLs in and see how much power they actually drew.

The 15W CFL spiked to 18W for a second but then settled in at 12W. After a while it climbed up to 13W and would have presumably stayed there. The 7W CFL globe settled at 5W. The incandescent was the odd one of the bunch, measuring 63 W instead of 60W. So when you replace those old lightbulbs, you may be saving a little more than you think.

Here’s the updated spreadsheet:

Again, the total lumen output might not be directly comparable because the LED bulbs really only emit light from a half globe, while the other bulbs cast light in almost all directions. Depending on the fixture this might make the LED seem brighter in comparison.