November 19, 2013 Agenda 1.Roll 2.PowerPoint titled: Heat Technology 3.Video “Head Rush: Liquid Nitrogen Balloon”

Subject Area: Heat Technology EQ: What happens to most of the energy when fuel is consumed? Questions: 1.How do heating systems work? 2.How does a heat engine work? 3.How heat technology effects the environment?

Heat Technology Is it a surprise to know that the heater in your home is heat technology? How about automobiles, refrigerators, and air conditioners? These are all heat technology!

Heating Systems Many homes and buildings have a central heating system that controls the temperature in every room.

Hot-Water Heating In a hot-water heating system water is heated by the burning of fuel (usually natural gas or fuel oil) in a hot water heater. The hot water is then pumped through pipes into a radiator in each room where it heats the air and cools the water, then the water will circulate back around to get heated again. Partner Question: What is a Hot-water system? A Hot-water system is …

Warm-Air Heating In a warm-air heating system the air is heated in a separate chamber by the burning of fuel (usually natural gas) in a furnace. The warm air then travels through a series of ducts and enter a room through vents. As the air cools it then is forced back into the furnace where it is heated again and circulated back into the rooms. Partner Question: What is a Warm-air heating system? A Warm-air heating system is …

Heating and Insulation Thermal energy has a tendency to be transferred out of a house during cold weather and into a house during hot weather. Because of this heaters and air conditioners will run constantly during the winter and summer. This is very wasteful and expensive.

Insulation Insulation is a substance that reduces the transfer of thermal energy. Insulation will be used in walls, ceilings, and floor to help the house stay warm in the winter and cool in the summer.

Solar Heating Passive solar heating is just building a structure and counting on the sun to heat it.

Solar Heating An active solar system uses pumps and fans to move the Sun’s energy throughout the building. Water is pumped through a heating element on the roof and then pumped to a radiator where the fan will blow the heated air into the room.

Heat Engines A car uses heat because it has a heat engine. A heat engine is a machine that uses heat to work. They use combustion. Combustion is where fuel is mixed with oxygen and a chemical change producing thermal energy.

External Combustion Engine A steam engine is an example of an external combustion engine, the fuel is burned outside the engine. Coal is used to burn to heat the water. When the water is heated it expands which is used to move the piston. The piston will then turn the flywheel.

Internal Combustion Engine An internal combustion engine will burn the fuel inside the engine. A mixture of fuel and air will enter a piston and then when the piston moves up it compresses the fuel. Then a spark plug will ignite the fuel which will thrust the piston down. Then the piston moves up pushing the exhaust out. And continues on this rotation. Partner Question: What is the difference between an external combustion engine and an internal combustion engine? The difference between an internal combustion engine and an external combustion engine is …

Cooling Systems An air conditioner is a cooling system that moves thermal energy from a warm area inside a building or car to the warmer outside.

Cooling Systems Electrical energy is required to do the work of cooling. A compressor will compress a refrigerant which has a boiling point below room temperature. This makes it so it can be condensed easily.

Cooling System A refrigerator is another example of a cooling system. The refrigerator will continually transfer thermal energy through the coils in the back of the unit. This is why the back of the unit feels hot.

Heat Technology and Thermal Pollution Heating systems, car engines, and cooling systems all transfer energy to the environment. Unfortunately, too much thermal energy can negatively affect the environment.

Thermal Pollution Thermal pollution is the excessive heating of a body of water. This will occur near large power plants. Power plants will heat water to generate electricity. This is not always all used so it will be placed in the water. Increasing the temperature of water can have poor ecological results. Partner Question: How does heat technology affect the environment? Heat technology affects our environment by …

Summary 1.Answer the essential question “What happens to most of the energy when fuel is consumed?” 2.Your answer needs to be in complete sentences. 3.Place your answer at the bottom of the notes we did today. 4.Make sure you include what fuel is being consumed and how heat is involved. Use your notes to get the answers.

“Head Rush: Liquid Nitrogen Balloon” What did you know? 1.________________________________ 2.________________________________ 3.________________________________ What did you learn? 1.________________________________ 2.________________________________ 3.________________________________ What do you want to know? 1._________________________________ 2._________________________________ 3._________________________________