Doghouse by Alexandra and Anna
We're Anna and Alex, and our dog, Rupert, needs a cool place to hang out when it's hot. We live in Arizona, so it gets really hot in summer. We can't buy an air conditioner for Rupert's doghouse, so we wondered what else we could do to keep it cool. We found some answers at the Arizona Science Center. How can we build a doghouse to keep Rupert cool?
What did we do?
The Arizona Science Center showed us how to select a good color of paint for our doghouse. We put a dark colored model house and a light colored one under some sun lamps, and compared the temperature of each after 20 minutes. We also learned how to use evaporating water as a way to keep the air temperature comfortable. In Arizona, we call a device like this a "swamp cooler."
What did we find out?
The light colored house warmed up less than the dark one in our test, so we decided to paint Rupert's house light yellow. We also used a fan, some cloth, and a picnic cooler to make a swamp cooler for the house. Even though the sun heated up the doghouse, the swamp cooler dropped the temperature by more than ten degrees!
- You probably know that black absorbs lots of sun energy, and white absorbs little. What about red, green, blue, and yellow? Paint some shoe boxes with these different colors, and set them in the sun for 30 minutes. Use a thermometer to measure the temperature inside the boxes. Which color seems to absorb the most sun energy, and which absorbs the least?
- A swamp cooler works by using evaporation of liquids to cool things down. Do all liquids evaporate and cool in the same way? Find some cotton balls, a bulb thermometer, and four liquids, such as water salt water, vinegar, and rubbing alcohol (have an adult present!). Dip a dry cotton ball into the first liquid, attach it to the bulb of the thermometer, and wave it gently in the air. Watch what happens to the temperature. Replace the cotton ball with a fresh one, dip it into the next liquid, and repeat the test.
- Use this physical science investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!