To Conserve or Not to Conserve

OBJECTIVES

The student will do the following.

1. Present his/her own ideas of how energy is wasted at home and at work.
2. Analyze information on ways to conserve energy.
3. Develop and present a program on how to save energy in a specific area.

SUBJECTS

General Science, Physical Science

TIME

5+ class periods

MATERIALS

Each student sheet (included) identifies specific materials and requirements for the completion of the activity.

BACKGROUND INFORMATION

The most cost-effective and sensible approach to today's energy problems is practicing energy conservation. Each of us must realize that we cannot continue using energy at our present rate of consumption; we must look for ways to decrease our energy use. We can achieve this by being good consumers and changing habits that waste energy. Areas where each of us can have an impact on conserving energy are heating and cooling our homes; use of hot water in the kitchen, laundry, and barn, lighting and use of appliances in our homes and work places; and wise and proper use of transportation systems.

PROCEDURE

1. Introduce the concept of energy conservation to tile class.
2. Ask the students to help you generate a list of reasons it is important for people to conserve energy. Leave this list in a visible place where students can refer to it (you might use a flipchart).
3. Give the "Test Your Energy IQ" test (included) to the students as a pre-test. Have them grade their own tests.
4. Divide the class into four or five groups depending upon whether you wish to have your students address commercial and industrial energy conservation. Assign each group one of the student activity sheet sets. The groups are to complete the activities and then develop presentations based on their findings. Encourage them to do further research and make visual aids, and tell them that their job is to convince their classmates to conserve energy. Allow time for all the in-class procedures: one period for the students to plan (as a group) how they will complete their group assignments, one period for each group to plan its class presentation, one period to set the stage and to take the pre-test; at least one period to hear the presentations, and one period to take the post-test and close the lesson.
   

   Give them guidelines on the length of their presentations (for example, 15 minutes per group). You may want to remind them to be cautious when completing activities which require use of electrical appliances, fire, or other potential hazards Remind them of the importance of communicating with (and in some cases, getting permission from) parents in completing the activity sheets Give them a reasonable deadline for completing the home assignments.

   For your convenience, the five group titles and individual student activity topics are listed here:

   Group 1: Energy Savings in Heating and Cooling

   1. The Effect of Closing Doors 2. The Effect of Fireplace Damper Position 3. The Effect of the Fireplace on Home Heating 4. Comparing Different Home Heating Systems 5. Comparing Window and Wall Heat Loss 6. Window Insulation Survey

   Group 2: Hot Water Energy Savings

   1. Hot Water Loss from Leaking Faucets 2. Washing Dishes in Warm Vs Hot Water 3. Boiling With or Without Covering Pan 4. Taking Baths vs. Showers 5. Heat Loss from Long Hot Water Pipes 6. Washing Clothes in Cold vs. Hot Water

   Group 3: Lighting and Appliance Energy Savings

   1. How Many Watts for Seeing? 2. Comparing Energy Use of Appliance Brands 3. How Lighting Diminishes With Distance 4. Light Source Effectiveness 5. Schoolroom Lighting Survey 6. Home Light and Appliance Survey

   Group 4: Automobile Savings

   1. Comparing Gas Mileage 2. Fuel per Passenger Mile 3. Tire Brand/Type Survey 4. Tire Air Pressure Effects 5. Car Weight Effects 6. Planning Your Trips

   Group 5: Commercial and Industrial Energy Conservation

   1. Find Out About Your Local Utility 2. Demand Charges and How to Reduce Them 3. Your School's Bills and Energy Management 4. Industry/Home Bill Comparison and Billing Units 5. Code Requirements and Their Energy Costs 6. Industrial Plant Energy Balance

   NOTE: The activities and topics for Group 5 are more advanced than those for the other four groups, and you may choose to omit this group. If you plan to use it, you should smooth the way for the students by telling the school system's physical plant director, the school principal, local utility officials, and a selected local company's plant manager about the group and its objectives. You may be unfamiliar with the concept of demand charge (a charge to industrial customers for peak power requirements experienced even for an instant during an established period of time). The demand charge is added to the more usual kilowatt hour consumption charge

5. Once all the presentations have been made, give the class the 'Test Your Energy IQ" test as a post-test. Discuss tile answers to the test.
6. Continue with the follow-up below.

FOLLOW-UP

1. Discuss the energy conservation tips your class has discovered. Which ones do the students think they will really incorporate into their daily lives?
2. Discuss with the students how they can spread the knowledge they have attained about energy conservation to family and friends.
3. Ask the students what they think will happen to the earth and the human condition if we do not conserve energy in our daily lives.

TEST YOUR ENERGY IQ

Answer each question below (true or false) and rate yourself on your knowledge of energy use and abuse in the home and on the road.

Circle the letter of the correct answer.

ANSWERS

1. TRUE. R-value does mean the resistance a material has to the flow of heat. The higher the R-value, the better the insulating capability of the material.
2. FALSE. A fireplace can cost you energy, as fireplaces are often sources of heat loss. When the heating system is on, a considerable amount of heated air goes up the chimney.
3. TRUE and FALSE. The energy savings gained by keeping the draperies closed on the west-facing windows depends on the time of year. This is true in the summer, but false in the winter. In summer, keep the draperies closed to block out the hot sun. In winter, keep them open and let the sun into the room for extra heat.
4. TRUE. Thermal-lined draperies and outdoor awnings block the hot sun and keep your home cooler.
5. TRUE. A home will seem more comfortable if the humidity level is higher. A humidifying device not only increases comfort but helps save energy as well.
6. TRUE. Landscaping can affect home energy consumption. A lawn reduces reflective heat in summer. Trees that shed their leaves can provide shade in summer and allow warming sunlight to reach the house in winter.
7. FALSE. Your house will not warm up faster by setting the thermostat higher than the desired temperature. Set it at the proper temperature, and it will heat (or cool) your home just as quickly without wasting energy.
8. TRUE. Weatherstripping and caulking can save up to 10 percent of home energy costs.
9. FALSE. Insulation can trap hot air in the attic. Ventilating the trapped air will make the house stay cooler, and you'll use less energy.
10. TRUE. A dirty air filter will cause your furnace/air conditioner to run for longer periods of time. Check the air filter about once a month because a dirty filter restricts the flow of air.
11. TRUE. The lower the temperature on your water heater, the less energy you will use. You can regulate the temperature of your water heater with the thermostat. The higher the setting, the higher your energy bill. Check the setting on your water heater.
12. FALSE. A frosty refrigerator uses more energy than a defrosted refrigerator. Frost makes the refrigerator work harder to remove warm air. Never let frost accumulate to more than 1/4 of an inch.
13. TRUE. Food cooks faster in a covered pan. The kitchen will stay cooler as well. Turn the heat off a few minutes before the food is completely cooked. Retained heat will complete the cooking.
14. TRUE. You do not have to preheat an oven for broiling or roasting In addition, any food that cooks for more than one hour does not require a preheated oven.
15. FALSE. Using your oven is a very costly way to heat your kitchen.
16. FALSE. It takes twice as much hot water for a deep bath than for the average shower. This can increase your energy bill because heating water accounts for as much as 20 percent of home energy expenses.
17. FALSE. Place the water heater as close as possible to areas where hot water is needed. The longer the pipes, the greater the heat loss. If hot water pipes are exposed, it is a good idea to insulate them Insulated pipes keep the water warmer.
18. TRUE. Heating and cooling systems are the major residential users of energy, home heating and cooling can represent as much as 70 percent of your home energy bill.
19. TRUE. Refrigerators operate best at 38~ to 42⁰ Fahrenheit, while freezers operate best at 0⁰ Fahrenheit. Lower settings are unnecessary and waste energy.
20. FALSE. The home freezer is most efficient when filled to capacity.
21. FALSE. It costs money and energy every time a refrigerator door is opened
22. TRUE. Small appliances often use less energy than a range They are designed to do specific jobs, making cooking easier and usually quicker.
23. FALSE. If the flame on your gas range is blue, it is operating correctly lf the flame has traces of yellow, the burners have become clogged and should be cleaned.
24. FALSE. Fluorescent and incandescent bulbs of the same wattage do not produce the same amount of light. Fluorescent lights produce 3-1/2 times more light than incandescent bulbs of the same wattage.
25. TRUE. Clean, reflective surfaces increase efficiency. Also, if your oven is selfcleaning, wait until after you have used the oven and less energy will be required for the cleaning process.
26. FALSE. Putting frozen food directly into the oven means the food will require more cooking time Plan ahead and thaw frozen food in your refrigerator before cooking it.
27. TRUE. Much of the energy used in doing your family wash goes to heat the water. Using cold water as often as possible should decrease your energy bill.
28. FALSE. A large-capacity washer saves energy by handling in one load what a small washer must do in two loads.
29. FALSE. Do not dry as many clothes as possible in each load. You should sort the clothes by thickness before you place them in the dryer. It takes a longer cycle for slow-drying items.
30. TRUE. Be sure to take permanent press garments out of the dryer as soon as the cycle is complete. You probably will not have to spend energy ironing them.
31. FALSE. A clean filter saves energy and money by allowing a high rate of flow of clean hot air and reducing drying time.
32. TRUE. Turning off the dishwasher after the rinse cycle is complete or using the overnight dry setting can save you 1/3 of dishwasher operating costs.
33. FALSE. Trash compactors and waste disposers consume relatively small amounts of energy.
34. FALSE. Use cold water when running the garbage disposal. It is designed to work with cold water, and since hot water is a prime user (20 percent) of residential energy, this will save energy and money.
35. FALSE. A hand iron consumes as much energy as ten 100-watt light bulbs. Permanent press items save ironing time. Iron large batches of clothing at one time to avoid wasting energy reheating the iron.
36. FALSE. The faster you drive, the more gasoline you burn.
37. FALSE. When filling your car, remove the nozzle as soon as it cuts off and avoid possible spillage.
38. FALSE. The best way to warm up a car is to drive slowly until the engine reaches proper operating temperature.
39. TRUE. Safety and theft considerations aside, it takes less fuel to restart than to let a car idle for a minute or more.
40. FALSE. Check air pressure in your tires regularly Under-inflated tires increase gas consumption.
41. FALSE. Properly inflated steel-belted radials give better mileage and last longer.
42. TRUE. The lighter the car, the less gas it uses Always remove unnecessary weight from the car.
43. TRUE. A car that is properly tuned will get better mileage. The more smoothly your engine runs, the less energy it will require to operate.
44. TRUE. An air-starved engine will waste gasoline Keep the air filter clean and your mileage should increase.
45. TRUE. Underpinning, or a "skirt," is the most accessible and practical method of reducing heat flow for mobile homes.

GROUP 1

Energy Savings in Heating and Cooling

Experience has shown that the most cost-effective and sensible approach to today's energy situation is energy conservation. Each of us must realize that we cannot continue consuming energy at the present rate. We must look for ways to decrease our use of energy.

Heating and cooling our homes accounts for most of our residential energy costs. The purpose of these activities is to discover some important ways to decrease the consumption of energy in our homes.

Your group is to complete the following six activities and then develop a presentation to be given to the rest of the class.

First, you will want to meet as a group to discuss your assignment and to decide who will be responsible for which activities. For example, if there are six people in the group you may decide to each choose one of the six activities Once each person has completed his/her assignment, you will want to meet again as a group to discuss your findings and prepare your group's presentation for the class.

Activity 1: The Effect of Closing Doors

The purpose of this activity is to determine whether or not energy can be conserved by closing doors to unoccupied rooms. You will need a thermometer and the chart below for recording data. Record data for several rooms, such as bedrooms, bathrooms, and so forth. Measure the temperature at a spot in the middle of each room.

Room Temperature Chart

Choose:

1. A time when you can leave your home's heating system set at a constant temperature for several hours.
2. A time when weather and/or sun conditions are fairly constant so they will not invalidate your data. For example, after dark is a good time. If you start with doors closed, wait at least 2 hours before recording the temperature with doors open. What can you conclude about closing doors to unoccupied rooms and energy conservation? If you have air intake vents, do you think opening or closing them would make a difference?

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Activity 2: The Effect of Fireplace Damper Position

The purpose of this activity is to determine whether or not energy is conserved by keeping a fireplace damper closed. You will need access to a fireplace damper, a watch, and the chart below for recording data. Start by opening the damper in your fireplace. Then record the times when the heating system starts and stops. Do this for at least one hour. Close the damper and wait one hour. This gives the house temperature time to stabilize. Record the information again. Does the heating system run more with the damper closed or open? Remember not to (1) change the thermostat while the experiment is in progress, or (2) choose a time to conduct the experiment when sunshine or weather changes will invalidate your data.

Damper Chart

Activity 3: The Effect of the Fireplace on Home Heating

The purpose of this activity is to determine whether or not energy can be conserved by building a fire in the fireplace while the heating system is operating. You will need access to an open fireplace, a watch, and the chart below for recording data. Leave the thermostat for the home's heating system set on a constant temperature during the experiment. With no fire in the fireplace, record the time on your watch each time the heating system turns on and off. Then, using all safety precautions, build a fire in the fireplace. CAUTION: Have a parent or someone who is experienced assist you. Record the data. Does the heating system run more with or without the fire?

Fireplace Chart

Activity 4: Comparing Different Home Heating Systems

The purpose of this activity is to determine how much energy is used by home heating systems. You will need the chart below and transportation to stores or outlets carrying heating systems such as furnaces and heat pumps. Go on a "shopping spree" to several different stores or outlets that carry heating systems. Record the data on the chart below, or organize a chart that will better fit the data you accumulate. Note: if transportation is not available, try to collect the information by telephone.

Heating System Chart

How does the efficiency of one system compare to another? What are some noteworthy advantages or disadvantages of each for consumers?

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Activity 5: Comparing Window and Wall Heat Loss

The purpose of this activity is to determine how glass compares to wall materials in conserving energy. You will need a thermometer, the chart below for recording data, and access to windows on the north, south, east, and west sides of a home. Start by measuring the temperature of the inside glass of 4 windows (put the thermometer directly on the glass), one each on the north, south, east, and west sides of the house. Then measure the temperature of a spot on the north, south, east, and west walls which is at least 3 feet away in all directions from a door or window. Measure the temperature at each of the corresponding spots on the OUTSIDE walls and windows. Record all data.

Window vs. Wall Chart

Which material (wall or window) has the greatest variation in temperature from inside to outside? Does compass direction have any effect? If you were designing an energy-efficient home, how would you apply this data?

Activity 6: Window Insulation Survey

The purpose of this activity is to determine the energy-conserving properties of different window coverings. Pretend you own your home and are just moving in. You are in the process of choosing coverings for all your windows. Of course you want them to look good, but you are also concerned with whether or not they will affect energy consumption. You will need the chart below to record data and transportation to stores or outlets that sell window coverings. You may need to design another chart that better fits the data you accumulate. Go on a "shopping spree" to several different stores. Tell the shop attendants about your assignment and ask if they have information on heat loss for fabrics or other window coverings that they sell.

Note: If transportation is not available, try to collect the information by telephone.

Window Covering Chart

HOT WATER ENERGY SAVINGS

Experience has shown that the most cost-effective and sensible approach to today's energy situation is energy conservation. Each of us must realize that we cannot continue consuming energy at the present rate. We must look for ways to decrease our use of energy. Perhaps more than any other area of energy conservation, our daily routine habits (e g., the length of time we spend in the shower) affect energy consumption in the amount of hot water we use.

In these activities, you will explore ways to decrease hot water consumption by changing habits and being informed consumers. Your group is to complete the following six activities and then develop a presentation to be given to the rest of the class. Your presentation should be based on the data you collect during completion of the activities. First, you will meet as a group to discuss your assignment and to decide who will be responsible for which activities. For example, if there are six people in the group you may decide to each choose one of the six activities. Once each person has completed the assignment, you will meet again as a group to discuss your findings and prepare your presentation for the class.

Activity 1: Hot Water Loss from Leaking Faucets

The purpose of this activity is to determine how much water is wasted by leaking faucets. You will need a faucet over a sink, a measuring cup, a watch with a second hand, and the chart below. First, turn the faucet on just enough to get one drop every second. Place the measuring cup under the faucet. Record the time. Then record the time when the cup is full. Repeat the procedure for 2 drops per second and 3 drops per second. Calculate how much water would be wasted in a day, a month, and a year for each drop situation.

Water Loss Chart

*Conversion Factor: 1 gallon = 16 cups

Activity 2: Washing Dishes in Warm vs. Hot Water

The purpose of this activity is to determine whether warm water cleans dishes as well as hot water. The assumption behind this experiment is that if we cleaned more household items with warm water rather than hot water, we could save energy. You will need several soiled dishes or pots, dishwashing detergent, and hot and cold water. Choose dishes soiled with different kinds of food. For example, choose two dishes with bacon grease, two dishes with sugary juices, two dishes with melted cheese, or pairs of dishes with other foods. Clean one dish of each pair in hot water and one in warm water. Keep everything the same except for the temperature of the water, that is, use the same amount of detergent and scrub for the same amount of time. Dishes must be washed one at a time to avoid unequal soaking time. Record which dish of each pair was cleaned satisfactorily and which dish was not. What are your conclusions about cleaning with warm water? Is warm water acceptable for some, all, or no situations? What if you were cleaning bathtubs, tile, or basins instead of dishes?

Dish Cleaning Chart

Mark an X in the appropriate columns

Activity 3 Boiling With or Without Covering Pan

The purpose of this activity is to determine how much heating time can be saved by boiling water with a lid on the pan. The assumption is that if we can find ways to reduce the time a stove stays on during cooking, we can conserve energy. You will need a stove, a pot with a seethrough lid, a measuring cup, a watch with a second hand, and the chart below. Since you will be boiling water and need to watch the kettle, you may want to ask a friend or family member to stand by while you observe the boiling. First, put one cup of water in the pot. Turn the stove on high and record the time on your watch. Then record the time when the water starts boiling rapidly. Let the pot and stove cool to room temperature. Repeat this procedure with the lid on the pot. Is boiling time more, less, or the same with and without a lid? What can you conclude about people who are in the habit of cooking with lids?

Water Boiling Chart

Activity 4: Taking Baths vs. Showers

The purpose of this activity is to compare the amount of water used taking a bath with that used taking a shower. You will need adhesive tape, an empty 2-liter plastic container, a tub/shower, and the chart below. Start by calibrating the tub. To do this, pour exactly 20 liters of water into the tub. Mark the water level with a piece of good quality adhesive tape. Pour in 20 more liters and mark the 40-liter water level with tape. Repeat until the tub is nearly full. Once the tub is calibrated, drain the water in the tub to a comfortable depth. Record the depth of the water. On the next day, take a shower with the tub plugged. Take an adequate amount of time to clean your body thoroughly. Record the depth of the water. If possible, repeat the shower procedure for several days, or get other family members to collect data for you. What can you conclude about the amount of water you and your family use in bathing/showering?

Bath/Shower Chart

Please refer to the PDF download at the top of this page to view the rest of the lesson.

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