A freezer uses 100 kJ of electrical energy to move 330 kJ of thermal energy from inside the freezer to outside. We can determine how much the room temperature increases when 1 kg of ice freezes. a. How much thermal energy must be removed from 1 kg of 0oC water to turn into 0oC ice? (the latent heat of fusion of water is 320 kJ/kg) b. How much electrical energy is used to freeze the ice? c. What is the total energy, including waste heat, exhausted by the freezer into the kitchen? d. A kitchen contains 43 kg of air (specific heat capacity of 1.0 kJ/kgK). Before the ice freezes, the air temperature is 20oC. After the ice freezes, at which temperature will the air be: 22oC, 25oC or 30oC?

A freezer uses 100 kJ of electrical energy to move 330 kJ of thermal energy from inside the freezer to outside. We can determine how much the room temperature increases when 1 kg of ice freezes. a. How much thermal energy must be removed from 1 kg of 0oC water to turn into 0oC ice? (the latent heat of fusion of water is 320 kJ/kg) b. How much electrical energy is used to freeze the ice? c. What is the total energy, including waste heat, exhausted by the freezer into the kitchen? d. A kitchen contains 43 kg of air (specific heat capacity of 1.0 kJ/kgK). Before the ice freezes, the air temperature is 20oC. After the ice freezes, at which temperature will the air be: 22oC, 25oC or 30oC?

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter2: Matter And Energy

Section: Chapter Questions

Problem 26RQ: How many Btu of heat can be produced by 4 kWh ofelectricity?

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