Rosie’s glad you asked that!
He did an experiment with light bulbs in his own kitchen, where there are 12 recessed light fixtures in the ceiling. He wanted to learn which kind of light bulb, halogen, incandescent, compact fluorescent or LED, was hottest and which was coolest.
Rosie has an energy management computer in his house from Advanced Home Systems in Phoenix that measures how much power all of his home’s lights and appliances use. So he screwed incandescent bulbs into those 12 cans and turned them all on. Later, he replaced them with halogen bulbs, which are a type of incandescent. Next, he switched to CFLs, and finally, he put LED bulbs in all of the fixtures.
The energy management computer showed that the LEDs used less than half of the energy of the halogens or standard incandescents.
Rosie also wanted to know how hot the bulbs got, so he “took their temperature” as they burned. Again, the LEDs were the winner by far, with a temperature of 109 degrees, compared with 279 degrees for the halogen bulbs (see the comparison on the chart.)
Rosie took the temperature of four different kinds of light bulbs to see which was coolest. Here’s what he learned:
Type of bulb temperature
Halogen 279 degrees
Incandescent 215 degrees
CFL 148 degrees
LED 109 degrees