Make your own drinks cooler

Make your own drinks cooler

Can you really make a paper fridge?

Over the last few weeks, the sun has finally been making an appearance in the sky. Could summer be on it's way?

Just in case we do get a sudden heatwave, we though we'd better show you how to cool your drinks without a fridge (with the help of a great video from Questacon).

What you need:

  • Small plastic drink bottles x2 - the bottles should be the same size
  • Toilet or kitchen paper
  • Water at room temperature (make sure it's from the tap and is suitable to drink!)
  • Thermometer (optional)
  • A windy day (or use an electric fan if it's not windy)

How to:

  1. Fill the drink bottles with water.
  2. Wrap one of the bottles in two layers of toilet or kitchen paper.
  3. Wet the paper with water.
  4. Stand the two bottles next to each other. Put them outside if it's a windy day. If it's not windy, put the fan on next to them.
  5. After 20 minutes, take a sip of water from each bottle. Has the temperature changed?
  6. Check the temperature every five minutes. You can guess the temperature difference between the two bottles by tasting the water, or use a thermometer to be accurate. Is the water from one bottle cooler than the other?

What's happening?

The wet paper is acting as a refrigerator. The water evaporates from the paper, cooling the water inside the bottle.

For water to evaporate, it needs enough energy to turn from a liquid into a gas. When a molecule of water evaporates from the paper, it takes some of the heat from its surroundings. Using a fan or wind speeds up evaporation.

This is why we sweat when we're hot or doing exercise. Sweat evaporating from the skin cools us down. As a molecule of sweat evaporates from our body, it takes some of the heat from our body with it.

Curriculum information

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