Section 1.2Heat Technologies in Everyday Life

Technologies have come with a cost to the environment.

This has led to the need for choices.

Personal and Societal Choices

Standard of living is a measure of how well we live, including the level of technology that we use in daily life.

Making Sustainable Choices

Sustainable means that something can be maintained or continued. ◦We mean that we are trying to use our

resources wisely.

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Section 2.1States of Matter and the Particle Model of Matter

Everything in the universe is made up of matter.

It exists in three states: solid, liquid and gas.

One way that heat can affect matter is by causing a change of state.

This happens by adding or taking away heat energy.

Heat energy is a form of energy that transfers from matter at higher temperatures to matter of lower temperatures

Water Changes State

  Temperature

Boiling Point 100 ºC

Melting Point 0 ºC

Freezing Point 0 ºC

Condensation Point

100 ºC

Particle Model of Matter

All matter is made up of extremely tiny particles.

The tiny particles of matter are always moving.

Adding heat to matter makes the particles move around faster.

The particles have spaces between them

Heat and the Particle Model of Matter

Kinetic energy is the energy of movement.

Volume is the amount of space that matter occupies.

State Shape(fixed or takes the shape of the container)

Volume(fixed or fills container)

Size of Spaces(small, med, large)

Energy Level of Particles(low, medium, high)

Solid Definite or fixed shape

Fixed volume Small Low

Liquid Takes the shape of its container

Fixed volume Medium Medium

Gas Takes the shape of its container

No fixed volume; fills the container

Large High

The Effect of Heat on Particles

Transferring heat to a substance increases the kinetic energy of particles in that substance.

Transferring heat from a substance slows down the movement of particles in the substance.

Action Energy Transfer(absorb / release)

Particle Spacing(increasing/decreasing)

Melting Absorbs energy 

Spaces are increasing

Boiling Absorbs energy 

Spaces are increasing

Freezing Releases energy 

Spaces are decreasing (except in water)

Condensing Releases energy 

Spaces are decreasing

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Section 2.2Heat and Temperature

Temperature is a measure of how hot or cold matter is.

Total Kinetic Energy

The thermal energy of a substance is the total kinetic energy of all the particles the substance contains.

Heat is the energy that transfers from a substance whose particles have a higher kinetic energy to one whose particles have lower kinetic energy.

Total Kinetic Energy

Temperature is a measure of the average kinetic energy of the particles in the substance.

History of the Thermometer◦Page 202

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Section 2.3Heat Affect the Volume of Solids, Liquids, and Gases

Measuring Temperature with Thermometers

John Locke was an English scientist who demonstrated that our sense could not be trusted to measure temperature.

Take Home Experiment◦Take 3 bowls

Fill one with warm water (#1) Fill one with room temperature water (#2) Fill one with cold water (#3)

◦Put your left hand in #1◦Put your right hand in #3

Keep them there for 2 minutes◦Put both hands in #2

What do you feel?

Thermometer Scales

Inventor Innovation Date

Galileo Galilei First instrument for measuring temperature

1590

Gabriel Daniel Fahrenheit First accurate scale for measuring temperature

1714

Anders Celsius Developed the centigrade or celsius

1742 

Expansion and Contraction of Solids

The particle model of matter tells us that when the thermal energy of matter increases, so does its volume.

We say that the matter expands.

Expansion and Contraction of Solids

When the thermal energy of a solid decreases, its volume decreases and the solid contracts .

This process of expansion of substance caused by an increase in thermal energy is called thermal expansion.

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Section 2.4Heat Transfer by Conduction

Conduction

Conduction is the transfer of heat energy between substances that are in contact with each other.

This form of heat transfer is most common in solids.

Conduction

Materials that allow easy transfer of heat are called conductors.

Materials that do not allow easy transfer of heat are called insulators.

Conduction

Gizmo

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Section 2.5Heat Transfer by Convection and Radiation

Convection

Heat transfer through liquid or gas particles happens by convection.

This transfer of heat occurs in circular patterns called convection currents.

Both conduction and convection rely on the movement of particles.

Radiation

Radiation is transfer of energy by invisible waves that can travel great distances without relying on the transfer of energy between particles.

These invisible waves are called infrared waves.

Reflect or Absorb?

Objects that are shiny and light colors are good reflectors of radiant energy.

Dark and dull objects are good at absorbing radiant energy.

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Section 3.1Natural Sources of Thermal Energy

Thermal Energy

Natural sources of heat energy include: solar energy from the sun, geothermal energy from deep inside the earth, chemical energy from the burning of fuels and decaying from the breakdown of dead plants and animals.

Using the Sun’s Energy for Solar Heating

Solar heating systems are of two types: passive and active.

On the prairies, the combination of a passive and active solar system can usually meet 75% of a family’s heating needs.

Passive Solar Heating

The basic approach to passive solar heating to reduce heat loss and increase heat gain from the sun.

This means more insulation to reduce the loss of heat as well as an(a) increase in the amount of window space.

Active Solar Heating

Active solar heating systems usually have three components:◦a collector◦a heat storage unit◦a heat distribution system.

The collector includes copper tubing filled with water on a black surface covered with glass.

Costs and Benefits

The availability to everyone, the absence of pollution and radiation as a bi-products are examples of solar energy’s benefits.

The expense of installing a solar system, the fact that it does not meet all our needs and that a backup system is needed are all examples of solar energy’s costs.

Solar Energy

Solar Energy

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Section 3.2Heating System Technologies

Thermostats

“Thermo” means heat and “stat” means maintain.

The switch in a thermostat is a bi-metallic strip, which consists of two different metals where one of the metals expands faster than the other causing the strip to bend.

This action causes an electrical circuit to open and close that controls the heating device.

Thermostats

Car Thermostats

Fire Alarms (bimetallic strip)

Heating Systems

There are two types of heating systems: local and central heating systems.

Local heating systems provide heat for only one room or a small part of a building.

Central heating systems provide heat from a single source such as a furnace .

The heat is then transferred by a network of ducts, pipes and vents or openings.

Central Heating Systems

There are two forms of central heating systems: forced-air and hot-water heating.

Both systems rely on heat transfer by convection to move the heat through the room once it arrives from the central source.

Central Heating Systems

Forced-Air Heating Components

Hot-Water Heating Components

Furnace Boiler

Ducts Pipes

Vents Radiators

Blower Expansion Tank

Keeping Cool

Thermal energy is needed to create cold temperatures in devices such as refrigerators, freezers and air conditioners.

Keeping Cool

The basic components of a cooling system:◦a storage tank◦a compressor◦a freezer unit◦condenser coils◦a refrigerant.

The liquid, or refrigerant in the system evaporates at a very low temperature creating freezing temperatures.

Air Conditioners

How do they work?

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Section 3.3Heat Loss and Insulation

Heat Loss and Insulation

The thermal conductivity of a material reflects its ability to transfer heat by conduction.

Every material is given a number called an R-value.

The higher the R-value, the better the product is a providing insulation.

Heat Loss

Heat is lost in a home through the doors, windows, walls and roof.

Area of Heat Loss Innovation

Doors Weather srtipping; metal clad insulation

Windows Dual/triple pane windows; argon gas; expanding foam

Walls and Roofs Fibreglass; fibre-fill; expanding foams; rigid foam; concrete construction

Heat Inspections

Thermal Imaging Video

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Section 4.1Looking at Different Sources of Heat

Natural Resources

Renewable natural resources are those that can be replaced.◦Sun’s/Solar energy is an example of this type

of resource.

Non-renewable natural resources cannot be replaced.

Fossil Fuels

Fossil fuels are formed from the remains of plants and animals.

In 1995, almost 60% of the world’s energy needs were met by burning oil and natural gas.

Coal provided another 30%.This means that we depend upon fossil

fuels for 90% for all of our energy needs.

Costs

The cost in dollar of using fossil fuels are called the economic costs.

The negative effects on the environment of using fossil fuels are called the environmental costs.

Costs

The negative effect on people all together are the societal costs.

All three of these costs are also associated with alternative forms of energy as all things have a cost in one form or another.

Alternatives for Thermal Energy

Wind energy is the energy of moving air. It can be captured by windmills.

Today, we have high-tech devices specially designed to translate this energy into electricity.

A wind farm consists of dozens or hundreds of these high-tech devices.

Nuclear Energy

Nuclear energy is a process that uses small amounts of radioactive uranium to produce vast amounts of heat.

Uranium is a non-renewable resource. The fuel source requires special care in handling because it is harmful to living things.

Hydroelectric Energy

Energy generated by water moving through a dam is called hydro-electric power.

Artificial lakes called reservoirs are built to raise the water level to create more force as the water falls through the turbines.

This form of generating energy is clean and it’s renewable however there are costs.

Hydroelectric Energy

Dams and reservoirs upset or destroy local ecosystems and flood agricultural land.

Long distance transmission lines must be built from the generation site to where people can use the electricity.

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Section 4.2Energy Consumption

Energy Users

The three main energy users are homes, transportation and industry.

Of these, the biggest user of energy is industry.

Transportation

Cars and trucks are big energy users and major contributors to air pollution,.

Road, rail, air and marine transportation together account for about 66% of the oil used in Canada.

The burning of fossil fuels creates a gas called nitrogen oxides that are harmful to people with lung problems.

This gas appears as a brown haze in major cities.

Industry

Industry is the major contributor of chemicals called sulphur oxides which turn to sulphuric acid in the air and form acid rain.

An energy audit helps companies to identify areas where they can cut energy costs and reduce pollution.

Cogeneration

Cogeneration is the production of two forms of energy, usually electricity and heat.

Cogeneration sees heat/waste energy generated from the production of electricity go towards heating buildings.

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