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Kill A Watt® Master
Kill A Watt® Meter
The Kill A Watt® meter allows users to measure and monitor the power consumption of any standard electrical device. You can obtain instantaneous readings of voltage (volts), current (amps), line frequency (Hz), and electric power being used (watts). You can also obtain the actual amount of power consumed in kilowatthours (kWh) by any electrical device over a period of time from one minute to 9,999 hours. A kilowatt is 1,000 watts.
Operating Instructions
1. Plug the Kill A Watt® meter into any standard grounded outlet or extension cord.
2. Plug the electrical device or appliance to be tested into the AC Power Outlet
Receptacle of the Kill A Watt® meter. 3. The LCD displays all meter readings. The unit will begin to accumulate data and powered duration time as soon as the power is applied. 4. Press the Volt button to display the voltage (volts) reading. 5. Press the Amp button to display the current (amps) reading. 6. The Watt and VA button is a toggle function key. Press the button once to display the Watt reading; press the button again to display the VA (volts x amps) reading. The Watt reading, not the VA reading, is the value used to calculate kWh consumption. 7. The Hz and PF button is a toggle function key. Press the button once to display the Frequency (Hz) reading; press the button again to display the Power
Factor (PF) reading. 8. The KWH and Hour button is a toggle function key. Press the button once to display the cumulative energy consumption. Press the button again to display the cumulative time elapsed since power was applied.
What is Power Factor?
The formula Volts x Amps = Watts is used to find the energy consumption of an electrical device. Many AC devices, however, such as motors and magnetic ballasts, do not use all of the power provided to them. The Power Factor (PF) has a value equal to or less than one, and is used to account for this phenomenon. To determine the actual power consumed by an AC device, the following formula is used:
Volts x Amps x PF = Watts Consumed
Measuring Electricity Use
Background
Aside from refrigeration, electrical devices called plug loads account for about 27 percent of a home’s electricity use and almost 22 percent of the electricity used in schools. Plug loads include any devices that plug into an electrical outlet, such as refrigerators, microwaves, computers, printers, gaming systems, TVs, small appliances, clocks, etc. This activity helps students learn how much energy those devices consume and how much money it costs to operate them. At the close of the activity students will be asked to think about strategies for reducing their electricity consumption.
Objectives
Students will able to list the ways they use electricity. Students will be able to measure and infer or calculate which devices will use more electricity than others and cost more than others.
Time
1-2 class periods, depending on student experience and skill level
Materials
Kill A Watt® Meter Stopwatch or timer Calculators (optional) Kill A Watt® Meter master, page 33 Student Guide, pages 31-32
Preparation
Gather a variety of devices used in school, or if you’d rather focus on home energy use, at home. Review the use of the Kill A Watt® meter. If necessary, move things around to make electrical outlets more accessible to students.
Procedure
1. Review the use of a Kill A Watt® meter with students, projecting the master as needed. 2. Explain that students will be gathering data on electrical devices by measuring the power they consume when in use. They will use that data to calculate their electrical energy consumption and the cost of that electricity. 3. Show students the safe way to unplug and plug in devices with the meter. 4. Allow students enough time to gather data on enough devices around the room. For students with more math aptitude, record the data on the board from each device. Guide them in filling in the Measuring Electricity
Use activity and completing the calculations or allow them to proceed with basic instruction. For students with developing math skills, prompt the class to predict or find a device that measures less than 10 watts, 10-100 watts, 100-500 watts, 500-1000 watts, and over 1000 watts. Record each item on the board with its wattage. Ask the class how each item is used, and how often it is used, and then ask the students to write about which items they think will cost the most to use. 5. Discuss the results with students and brainstorm ways to save energy with pluggable devices or plug loads.
Extensions
Ask students to complete the Measuring Electricity Use activity again and look closely at each device for its changes in wattage during use in various modes or cycles (i.e., a copier in standby vs. a copier in use, or a laptop at full charge vs. a laptop charging). Have students hunt for “phantom loads” by looking for devices that are off/not it use and still drawing wattage. Ask students to discuss why they think this happens and to list or infer devices at home that might do this, too. For spreadsheet capable students, download and use NEED’s Plug Loads guide and pre-prepared spreadsheet to add data, complete calculations, and manipulate data to make suggestions about electricity use in the various spaces in your schools. Download the guide and spreadsheet from shop.NEED.org/products/plug-loads.
Lesson 3 – Climate Change and Its Impacts
Background
This lesson introduces the basics about climate change. The greenhouse effect, greenhouse gases and their origins, and the contributions of man-made (anthropogenic) sources of such gases on the greenhouse effect are discussed in these activities. The health and regional impacts of climate change are introduced, and students are challenged to consider how different groups of people in different areas might be experiencing greater climate change effects.
Objectives
Students will be able to describe the basic causes of climate change. Students will be able to list several sources of carbon dioxide.
Time
6-7 class periods
Materials
600 mL Beakers 250 mL Erlenmeyer flask Rubber stoppers with hole Vinyl tubing, 3/16” diameter Clip lights Rulers Digital thermometers Masking tape Alka-Seltzer® tablets Safety glasses Water (room temperature) 1000-1100 Lumen bulb, equivalent to 75-watt incandescent Ball of yarn or string Scissors Hole punch Cardstock Masters, pages 36-37 Climate Web Hangtags, pages 41-46 Student Guide pages 17-22; 33-45
Preparation
Gather materials needed for the activities. Prepare digital copies of masters for projection.
Procedure
1. Introduce climate science and differentiate climate from weather. Explain that climate is the accumulated data set over large amounts of time, while weather measures what is happening in any given short time period, such as a day, a week, or several weeks. Use the student text to discuss climate changes. 2. Project the Carbon Cycle master. Show how carbon circulates through different reservoirs. 3. Project the Greenhouse Gases master. Explain that they all are able to absorb thermal energy in their bonds and release it slowly over time, and that the greenhouse effect is what keeps our planet warm at night. Focus on carbon dioxide and explain the sources of carbon dioxide emissions in the various sectors of our economy. a. Residential sector: burning natural gas, fuel oil, or propane in furnaces, boilers, water heaters, stoves, and barbecue grills. b. Commercial sector: burning natural gas, fuel oil, or propane in furnaces, boilers, water heaters, or commercial stoves or ovens. c. Industrial sector: burning coal or natural gas for intense heat in industries like cement or steel. d. Transportation sector: burning gasoline, diesel fuel, or jet fuel, which are products of petroleum. Some trucks and buses burn natural gas or propane. e. Electrical power sector: burning coal or natural gas to heat water into steam and turn a turbine, generating electricity. 4. Introduce the Greenhouse in a Beaker lab. Explain the activity and allow students enough time to complete it. 5. Introduce Carbon in My Life. Lead students through all of the worksheets and help them determine the size of their own carbon footprints. Discuss with the class the actions they listed on the action planner in the Student Guide. 6. Lead students through the Climate Web activity. You may need to assist younger students in the reading of the cards, and it may be necessary to help students find connections among things with which they are less familiar.
