Book 3, Question 47
Why Does a Fridge Stay Cold?
A fridge doesn't make cold. It pumps heat out of the box! Cold is just less heat.
From the book
Page from A Million Whys Book 3
More fun facts
- A fridge does not make cold. It pulls heat out of its inside and dumps it outside.
- A liquid called refrigerant flows through the fridge. It turns into a gas to soak up heat inside, much like sweat drying off your skin cools you.
- Outside the cold box, the refrigerant turns back into a liquid and gives off the heat it carried.
- Experts say to keep your fridge at 5 degrees Celsius or below and not overfill it, so cold air can move around.
- Most fridges are designed to work in room air up to about 32 degrees Celsius, so very hot days make them struggle.
- Since 2020, astronauts on the International Space Station have had fridges just for food.
- A fridge meeting newer U.S. rules uses 215 to 270 dollars less electricity a year than one meeting the first rules set in 1978.
Sources: Smithsonian Magazine, BBC, National Geographic
Questions kids ask
Why is the back of a fridge warm?
The fridge moves heat from inside to the outside, and much of it comes out near the back.