Science ideas for young children: Defrosting windows

How does a window defroster work? Use some simple experiments to learn about science.

I was waiting at the end of the driveway with my 4-year-old son the other day and he was watching the frost melt off the car’s windshield. I used this time to ask him some science-related questions about defrosting windows.

Here are some questions you can ask youth and experiments you can try:

  1. Why do windows frost over? Is there frost over everything outside? Why might some things frost over and some don’t? How are the things that frost over different from those that do not? Could you put some items in your freezer and see if they get frost on them?
  2. Why don’t the windows on your house frost over like the windows in the car? (This might not be true if you have old windows in your house.)
  3. Where does frost come from? Is it the same as snow?
  4. As frost disappears from the windshield, where does it go?
  5. If you touch the outside of a frosted window with your hand, what will happen? Why?
  6. What happens when you turn the defroster on? Do different things happen on the front window versus the back window? Why are they different?
  7. Where does the frost melt off the window first? Why?
  8. What do you think will happen if you breathe close to the window? Will it frost back up? Try it. Where does the fog on the window come from? How long will the fog stay there? Is there anything you can do to make the fog go away faster?
  9. What happens when you adjust the fan speed on the defroster? Will air blowing faster make frost melt off the window quicker? Why?
  10. If you have an infrared thermometer (a temperature gun), use it to notice what parts of the window are colder or warmer. How warm does the window need to be before frost will melt?

While you are waiting for the windows to defrost, take advantage of the time to ask questions and learn about science.

Michigan State University Extension encourages families, daycares, school activities, 4-H clubs or any group working with young children to conduct these experiments. The focus of these lessons aren’t to simply impart knowledge, but to facilitate the joy of discovery and the exploration of the world around us. This is not designed to “give youth the answers,” but to empower them to ask questions and figure things out on their own. When a young person asks a question, resist the urge to answer it, and instead ask, “What do you think?”

Did you find this article useful?