Do now Discussion: The coolant used inside of a refrigerator gets hot very easily and also gets cold very easily. How might you describe its specific heat? Teaching Point: “To model how coolants move heat from inside of a refrigerator to the outside.”

Let’s Review Refrigerators Refrigerators are heat movers.  They take the heat from our food and move it to the outside of the refrigerator. Moves Heat Outside Air TP: “To model how coolants move heat inside of a refrigerator.”

Coolants Take Out the Heat Refrigerators have a special liquid/gas inside of them called a coolant  Coolants act as a heat sink, sucking in the heat from the hot food and moving it into the outside air. Moves Heat Outside Air TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle Area Inside Frig Area Outside Frig 1. Heat leaves warm food heating air inside refrigerator TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 2. Heat in air moves into the cold coolant making it hot Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 3. Coolant is now hot Hot Coolant Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 4. Hot coolant moves to the outside of the refrigerator Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 5. Hot coolant releases heat to the air and cools down Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 6. Coolant is now cold Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

The Refrigeration Cycle 7. Cold coolant goes back inside the refrigerator starting the process over again Area Inside Frig Area Outside Frig TP: “To model how coolants move heat inside of a refrigerator.”

Mid-Lesson Assessments Take out your own Plicker Card. You should all have a number assigned to you. When you see the answer you think is correct, turn your card so the multiple choice answer letter of your choice is facing up Wait until the entire class is done, and do not change your answer based on others! TP: “To model how coolants move heat inside of a refrigerator.”

Mid-Lesson Assessment 1.A coolant is used to move heat from inside a refrigerator to outside of it True or False 2.Where is the coolant acting as a heat sink? a. Outside the refrigerator with the air b. Inside the refrigerator with the warm food c. Outside the refrigerator with the warm food d. None of the above TP: “To model how coolants move heat inside of a refrigerator.”

The first refrigerators used a coolant that contained chemicals called “CFCs” which was damaging to the Earth’s ozone layer. The ozone layer protects life on Earth from harmful ultraviolet radiation from the Sun. It took the work of many lawyers who fight for the environment and eventually ban the use of the chemical. Do you think it was easy for the lawyers to get the chemical banned from refrigerators? Why or why not? Intellectual Engagement TP: “To model how coolants move heat inside of a refrigerator.”

Instructions: Using what we have just learned about the refrigeration cycle and how heat is moved… Task A- write a short paragraph explaining how a part of the refrigeration could be stopped if something in the refrigerator were to break. Task B- create a cause and effect diagram for how heat is moved from inside of a refrigerator to the outside by a coolant. Task C- compare and contrast a refrigerator with an air conditioner (they both use coolants!) For an extra challenge, draw an illustration of how an air conditioner might work. Flexible Group- take out your portfolio and meet me at my desk for a conference TP: “To model how coolants move heat inside of a refrigerator.” Class Activity- Refrigerators

Lesson Summary In your tables of four, go back into your notes and consider what we have just learned today, and then… 1. Identify three (3) important concepts we learned today 2. Place those the three in order from the most important concept to least important. TP: “To model how coolants move heat inside of a refrigerator.”