UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
Does the color of the light bulb affect the temperature around it?
Answer 1:

The color of the light bulb might affect the temperature around it slightly, but it's more complicated than that. It turns out that power and efficiency affect the temperature much more strongly.

The power of the light bulb is a number in watts (W) or kilowatts (kW) that tells youhow much electricity the bulb needs. Some of that electricity gets turned into light, and some of it gets turned into heat. The efficiency of the light bulb tells you how much. For example, a 5%-efficient bulb turns 5% of its electric energy into light and the rest (95%) into heat.

Together, power and efficiency tell you how much light and heat are generated. High power, high efficiency light bulbs generate the most light intensity. High power, low efficiency light bulbs generate the most heat.

So what about color? Different colors of light have different amounts of energy. From lowest energy to highest energy, the order is: red, orange, yellow, green, blue, and violet. But this only matters if you're comparing light sources with the same intensity. Also, this light only turns into heat when a surface absorbs it. Since the goal of the light bulb is to radiate light to the whole room, ideally the light bulb will not absorb too much of its own light.


Answer 2:

No, the color of the light bulb does not affect the temperature around it. However, fluorescent bulbs are more energy-efficient than incandescent bulbs, so they will put out less heat for the same amount of light. Still, a 40-Watt bulb is a 40-Watt bulb.



Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use