Lesson Plan: The Appliance Explosion (4-10)

Adapted from the NY Energy Education Project

Essential question: How can we apply what we learned by exploring our school, homes and other buildings within the community? How has appliance use changed over time?

Overview

Students collect data on the number of appliances owned by students and adults, and construct a bar graph to show changes in appliance use over time.

Objectives

Students will be able to:

• Conduct a survey
• Collect and record data
• Construct a bar graph
• Interpret results

Student will understand:

• Today’s homes have many more appliances than the homes of a generation ago.
• The kinds of appliances used today are different from the kinds used a generation ago.
• One reason for this increase in appliance use was the ready availability of “cheap” energy between 1945 and the early 1970’s.
• There are appliances that are essential and others that are nonessential to the well-being of the family.
• Increased use of solar energy can reduce reliance on fossil fuel and electrical energy in the home.

Time

• One class period to present background information and to give the assignment on the survey and floor plans.
• One class period to tabulate class frequencies, complete the class floor plan, and construct bar graphs.
• One class period to discuss results.

Subjects

Home Economics, Social Studies, and Science

Suggested Grade Level

4th – 5th, or 5th – 10th

Materials

Student sheets (included)

Precautions

• Some parents may regard this activity as an invasion of privacy. A statement to parents of the activity’s purpose, along with permission slips to be signed by parents, is suggested.
• It may be necessary to give students several days to complete the assignment. The survey is long.
• Substitute a different floor plan if the one given is not appropriate for the socio-economic level of your students.

Preparation & Background

Advance Planning

• Review background information to prepare for class discussion.
• Duplicate survey, floor plans, and Home Appliance Use sheet for distribution to students (each student should receive two floor plans).
• Collect store catalogs for students to use to look up appliances with which they are unfamiliar.
• Collect materials for the Appliances Use Display.

Background

Today the world faces an energy crisis. As of 2007, ninety-three percent of the energy consumed in today’s world comes from fossil fuels. But fossil fuel reserves are being used at a tremendous rate and new resources are not being discovered to keep pace. It is estimated that at current rates of use, our known reserves of petroleum will run out in thirty years and natural gas in twenty. Coal may last several hundred years more, but there are serious environmental problems associated with increased use of coal. Even uranium for nuclear fission is in short supply.

As a result, petroleum and natural gas have become much more expensive and people are recognizing the need to conserve, both to save money and to direct valuable resources to other needs. The United States, especially, has much room for conservation; five percent of the world’s population consumes twenty-five percent of the world’s resource production each year.

Twenty-one percent of the energy used in the United States is consumed in the home. Of this, 47% is for heating, ventilation, and cooling; 24% goes to lighting and appliances; 17% for water heating; and 12% for all other uses of energy. When considered as a nationwide total, residential energy consumption becomes a large factor, and conservation of home energy can lead to substantial reductions in energy use.

Table 1 shows the per capita increase in domestic energy consumption since 1950.

Source: Energy Information Administration, Energy Perspectives: 1949-2002, http://www.eia.doe.gov/emeu/aer/ep/ep_frame.html

Residential electrical energy use grew at an average rate of 2% per year from the 1950’s to the late 1970’s. It is easy to see that the rapid increase in home appliance use found in this activity contributed substantially to this growth rate.

Over the past few years, much research has gone into finding and exploring renewable sources of energy, including solar and wind energy, hydropower, and biomass conversion. The total amount of energy produced by the sun is tremendous, much more than we could possibly use. So the sun is being investigated as a potential source of unlimited, clean, and safe energy.

Table 2 indicates how energy use is distributed in the home. Replacement of the energy used in some of these functions by renewable energy would result in substantial conservation of fossil fuel resources.

The easiest areas in which to utilize renewable energy are space heating, water heating, and air conditioning, which make up a substantial proportion of the total. Solar water heating has been shown to be cost effective even in the northern states. Woodburning stoves can provide an auxiliary means of space heating that is also cost effective at today’s oil prices.

Replacement by renewable energy of the fuels used to power electrical appliances and lights is not yet a viable alternative, since photovoltaic cells, which convert solar energy directly to electricity, remain very expensive to produce. However, it is expected that their cost will fall substantially in the next few years with new techniques for manufacturing and mass production.

Source: Energy Information Administration http://www.eia.doe.gov/kids/energyfacts/uses/residence.html

Suggested Approach

1. Discuss the background information with the class.
2. Explain how the activity will be carried out.
3. Have students carry out the activity and collect data as a homework assignment. Data will include numbers of appliances owned by students and adults.
4. Have an individual student or committee of students create the Appliance Use Display. Alliance to Save Energy’s Green Schools Program 4
5. If necessary, give students instruction in constructing bar graphs.
6. Discuss the results and implications of the activity as a class.
7. A blackboard can be used to compile class frequencies of appliances. An alternative approach could be to assign different groups to tabulate different appliances. If this method is used, it would lessen confusion if student surveys or floor plans were collected, copied, cut into sections, and then the sections distributed to the various groups for tabulation and construction of graphs. These graphs could then be displayed in the room.

For Discussion

1. Which appliances are listed most frequently by both students and adults? Which ones are listed least frequently?
2. What will happen in the future to energy supplies if energy use continues to increase in this way?
3. Use a brainstorming technique to discuss how solar energy can help reduce fossil fuel and electrical energy consumption in the home.
4. Discuss ways in which energy can be saved by judicious appliance use.

Typical Results

• Most students will find that they have at least twice as many appliances in their homes as people did a generation ago.
• Results for class frequencies will vary depending on the appliance and the number of students in the class.

Assessment

1. Observe students’ skill in carrying out the assignment, completing the survey, recording data, compiling statistics, and graphing and interpreting data.
2. Check the quality of students’ answers to questions.
3. Ask students to group appliances into essential and nonessential categories. Have them explain the reasons for their choices.

Modifications

1. If class time is short, some sections of this activity, such as the floor plan or bar graphs, can be eliminated or completed as homework.
2. Analyze the number of kilowatt-hours used by various electrical appliances.
3. Give students an energy budget of a certain number of kilowatt-hours they can use daily and discuss how they would allot their budget. Refer to transparency A23 for electric appliance energy requirements. Cut the students’ daily allotment. Now how would they spend their energy budget?
4. If your students feel uncomfortable about talking about their home appliances, then create a collage of old appliance vs. new appliances or interview a grandparent or older adult and compare appliances of different decades.

Refer to the PDF download here or at the top of this page to view the entire lesson.