| A | B |
|---|
| What are types of central heating systems? | forced air, hot water, steam, radiant, and heat pumps |
| What system uses energy supplied by the sun? | active and passive solar heating |
| What stops the flow of heat from a building to the outside? | insulation |
| What do cooling systems use to transfer heat? | evaporation and condensation |
| How does your body cool itself? | sweat-which absorbs heat as it evaporates from your skin |
| What are the basic parts of a refrigerator? | compressor, condenser coils, storage tank, and refrigerant |
| How do refrigerants work? | evaporate at low temperatures to remove heat from an enclosed space |
| How do heat engines work? | burn fuel to convert heat energy into mechanical energy |
| What types of heat engines are there? | internal-combustion or an external-combustion engine |
| Name examples of internal-combustion engines. | gasoline or diesel engines |
| What is the most common external-combustion engine? | steam engine |
| What is used to control a central heating system? | thermostat |
| What type of currents do forced-air heating and hot-water heating create? | convection currents |
| What types of fossil fuels are used to heat buildings? | oil, natural gas, and coal |
| What types of materials are used to make insulation? | fiberglass, cellulose, metal foil, and some types of plastic foam |
| Where is insulation usually placed to prevent heat loss? | ceilings, attic floor, and the outside walls |
| What occurs with a higher R-value? | the greater its ability to trap heat energy |
| What is sweat? | a mixture of water and dissolved solids, such as salt, urea, and fats |
| What are examples of natural refrigerants? | air, water, ammonia, and carbon dioxide |
| What manufactured chemical do most cooling systms use? | fluorocarbons |
| What is ozone? | protects life on Earth from harmful radiation from the sun |
