Chapter 5 / Section 3: Using Thermal Energy

Thermal energy can be made useful by controlling its transfer and by transforming it into other forms of

energy.

Essential QuestionsWhat are some common types of heating systems?What are the first and second laws of thermodynamics?How does an internal combustion engine work?How does a refrigerator work?

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Heating Systems

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Heating SystemsMost buildings contain some type of heating system.

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Heating SystemsMost buildings contain some type of heating system.

Oldest method – wood or coal-burning stove.

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Heating SystemsMost buildings contain some type of heating system.

Oldest method – wood or coal-burning stove.Forced-Air Systems: most common type of heating system in use today

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Heating SystemsMost buildings contain some type of heating system.

Oldest method – wood or coal-burning stove.Forced-Air Systems: most common type of heating system in use todayRadiator System: Hot water or steam – conduction and convection used to spread.

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Heating SystemsMost buildings contain some type of heating system.

Oldest method – wood or coal-burning stove.Forced-Air Systems: most common type of heating system in use todayRadiator System: Hot water or steam – conduction and convection used to spread.Electric Heating Systems: Conduction and convection spread heat in individual coil systems.

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Heating SystemsMost buildings contain some type of heating system.

Oldest method – wood or coal-burning stove.Forced-Air Systems: most common type of heating system in use todayRadiator System: Hot water or steam – conduction and convection used to spread.Electric Heating Systems: Conduction and convection spread heat in individual coil systems.Solar Heating: radiant energy from the Sun can be used to help heat homes

Active and Passive

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Active Solar HeatingSolar collectors used that absorb radiant energy from the Sun. roof or south side of a building

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How is our school heated?

How much do you think the heating bill at Mall of America costs?

Mall of America® By The Numbers•8 acres of skylights allow about 70% of the natural light to enter the Mall•4.3 miles of total store front footage•7 Yankee Stadiums can fit inside the Mall•27 rides and attractions in Nickelodeon Universe®

•32 Boeing 747s could fit inside the Mall•70 degrees inside Mall of America whether its spring, summer, winter or fall•258 Statues of Liberty could lie inside the Mall•12,550 on-site parking spaces at Mall of America in two ramps•30,000+ live plants and 400 live trees climbing as high as 35 feet tall in Nickelodeon Universe•32,000+ tons of trash recycled each year•4.87 million square feet of gross building area•40 million visitors annually which is more than the combined populations of North Dakota, South Dakota, Iowa...and Canada•If Mount Rushmore was divided into individual monuments, a president could reside in each of the Mall’s four courts

Thermodynamics

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ThermodynamicsThermal energy, heat, and work are related, and the study of the relationship among them is thermodynamics.

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Heat and Work Increase Thermal Energy

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Heat and Work Increase Thermal Energy You increase the energy of a system whenever you do work on that

system or heat that system.

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The First Law of Thermodynamics

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The First Law of ThermodynamicsThe energy in a system remains constant, even thought it changes forms.

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The Second Law of ThermodynamicsEnergy spontaneously spreads from regions of higher energy to regions of lower energy.

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Converting Thermal Energy to Mechanical Energy

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Converting Thermal Energy to Mechanical EnergyHeat Engine. Gas converts to thermal energy. Engine transforms thermal energy into mechanical energy by

rotating the car’s wheels.

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Internal Combustion EnginesThe heat engine in a car is an internal combustion engine in which fuel is burned inside the engine in chambers or cylinders. Each cylinder contains a piston that moves up and down. Each up-and-down movement of the piston is called a stroke.

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Internal Combustion Engine

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https://www.youtube.com/watch?v=SYd40qWQ9Bc

Other Thermal Energy TransfersRefrigeratorHeat PumpsAir conditioners

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The Human CoolantYour body uses evaporation to keep its internal temperature constant. As you exercise, your body generates sweat. As the sweat

evaporates, it carries away thermal energy.

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Geothermal Heathttps://

www.youtube.com/watch?v=FgIuEk26J5Q