Cool Roofs Can Help Hot Cities
Key Vocabulary
| Word / Phrase | Meaning | Example |
|---|---|---|
| roof | the top part of a building | The house has a white roof. |
| reflect | to send light or heat away from a surface | Light colors can reflect more sunlight. |
| absorb | to take in heat, light or liquid | Dark surfaces absorb more heat. |
| air conditioning | a system that cools the air inside a building | The office uses air conditioning in summer. |
| surface | the outside or top layer of something | The roof surface becomes hot in the sun. |
Article
Cities can become very hot in summer. Roads, buildings and dark roofs absorb heat from the sun. This can make cities warmer than nearby areas. [2]
A cool roof reflects more sunlight. It does not become as hot as a normal dark roof. [1]
Cool roofs can help keep the inside of a building more comfortable. The U.S. Environmental Protection Agency says they can also reduce the need for air conditioning. [1]
A cool roof does not always need to be completely white. Some special materials and paints can reflect heat in different colors.
Cool roofs are especially useful in hot and sunny places. They may be less helpful in very cold places because winter sunlight can sometimes help warm a building. [1]
A roof is only one part of a city. But if many buildings stay cooler, the whole neighborhood may also become a little cooler.
Discussion Questions
- Which parts of your city become very hot?
- What colors are most roofs where you live?
- How do people keep homes cool in your country?
- What are some ways cities can create more shade?
- Would you choose a cooler roof even if it looked different from other houses?
References
- U.S. Environmental Protection Agency, "Using Cool Roofs to Reduce Heat Islands."
- U.S. Environmental Protection Agency, "What Are Heat Islands?"
- U.S. Department of Energy, "Guidelines for Selecting Cool Roofs."