Lesson: Capturing the Sun’s Warmth
(Provided courtesy of Teachengineering)
Level: Grades 4 (3-5)
Time Required: 120 minutes (30 minutes is required for teams to paint their cardboard boxes a day or two before the rest of the activity)
Cost per group: $2
Summary
In the exploration of ways to use solar energy, students investigate the thermal energy storage capacities of different test materials to determine which to use in solar building design.
Engineering Connection
Passive solar heating systems are simple and efficient ways to heat structures. When designing houses, engineers carefully choose insulation so it does not act as a passive heating system during high temperature days and during the spring and summer months. Engineers must design the insulation to reflect the internally-produced heat (to prevent it from escaping from the house) on cool days, as well as choose roof material that reflects the sun’s heat on hot days.
Educational Standards
Next Generation Science Standards
- 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem
- 4-PS3-2. Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents. (Grade 4)
International Technology and Engineering Educators Association
- Energy comes in different forms. (Grades 3 – 5)
- Models are used to communicate and test design ideas and processes. (Grades 3 – 5)
Materials List
Each group needs:
– Cardboard box (large enough to accommodate four cans with thermometers; ask students to bring from home)
– 4 small metal cans (all about the same size; ask students to bring from home)
– 4 non-mercury thermometers
– Paintbrush
– 1 cup (~250 ml) sand
– 1 cup (~250 ml) salt
– 1 cup (~250 ml) water
– 1 cup (~250 ml) shredded newspaper
– Capturing the Sun’s Warmth Worksheet, one per group
For the entire class to share:
– Black paint
-Newspaper (to put under the boxes while painting)
-Masking tape
-Marking pens
-Measuring cups (or jars with 1 cup [~250 ml] level marked; ask students to bring jars from home)
-1-2 extra non-mercury thermometers
-Chopsticks or plastic utensils for stirring
-Sunglasses and other appropriate sun protection
-Several potholders or gloves
Reuse/recycling/disposal note: Recycle the cans and shredded paper. Collect and reuse the salt and sand. Throw away newspaper with paint on it.
Introduction/Motivation
Have you ever wondered how your house stays warm in the winter and cool in the summer? Have you ever noticed that sometimes when it is cold outside, it is nice and warm in a sunny spot next to a window inside? Well, the sun is full of energy. We can use the sun’s energy (solar energy) to help us heat our homes.
There are two ways civil engineers use solar energy to keep comfortable building temperatures: active solar heating and passive solar heating. Active solar heating systems use mechanical and electrical components to control the movement of warmed air or water. Passive solar systems use only the structure (floors, walls, windows) to collect, store and distribute heat from the sun in the winter and keep heat from the sun out in the summer.
Procedure
Before the Activity
-A few days in advance, gather boxes, cans and jars from the students.
-Divide the class into teams of four students each.
-A day or two before the activity, set aside ~30 minutes for teams to paint the outside of their cardboard boxes black -Gather remaining materials and make copies of the Capturing the Sun’s Warmth Worksheet.
-Set up insulation material stations for sand, salt, water and shredded paper, each with measuring cups or jars.
With the Students
1. Have each team use masking tape and markers to label their four cans: sand, salt, water, shredded paper.
2. On their worksheets, have students predict which material they think will store solar thermal (heat) energy the best.
3. Have each team member place 1 cup (~250 ml) of test material in its labeled can and place a thermometer in the center. When filling a can with sand or salt, pour in half of the material, add the thermometer, and then pour in the rest of the material.
4. On their worksheets, have students record the initial temperature of each material.
5. Place the cans inside the box and close the lid. If necessary, tape the lid closed.
6. Move the cans and boxes outside to a sunny location.
7. Use an extra thermometer to record the nearby outside air temperature, too, as a control.
8. Leave the boxes for 30 minutes.
9. Have one or two students take spare thermometers outside to measure and record the outside air temperature (as a control), and share the data with all teams.
10. Have teams take turns opening their boxes. Have students record on their worksheets the temperature of the materials in each can. Then, close the boxes and leave them for another 30 minutes. Repeat this step one to three times. Use the back of the worksheet to record any data that does not fit in the data table.
11. Put on potholders or gloves. Carefully stir the contents of each can occasionally and watch to see which temperature falls the slowest and which falls the fastest. Record this on the worksheet.
12. Have teams complete the worksheet by graphing their results.
13. Conclude with a class discussion to compare results. What can we conclude from our data? What do the graphs show us? Which material stores thermal energy from the sun best? Who predicted this correctly? How did the material temperatures compare to the outside air temperature at each measurement time? Which test materials lost heat the fastest? The slowest? See additional post-activity discussion questions / answers in the Assessment section.
Attachments
Capturing the Sun’s Warmth Worksheet
Assessment
Pre-Activity Assessment
Prediction: Have the students predict which material they think will be the best thermal mass, or store the most solar energy. Record their predictions on the worksheets and the board.
Activity Embedded Assessment
Worksheet: Have students record measurements and follow along with the activity on their team worksheet. After students have finished their worksheet, have them compare answers with their peers. Review their worksheets to gauge their mastery of the subject.
Graphing: Have students create line graphs on their worksheets, showing how the temperature of each test material changed over time.
Class Discussion:
Discuss the following solar concepts with the students:
-Which of our test material(s) would be a good thermal mass (be the best at storing heat from the sun)? (Answer: Of the test materials, water or salt are the best. Even though sand is not a good thermal mass, it is better than paper, plastic or wood.)
-Which test material(s) would make good insulation (did not store the heat well)? (Answer: Shredded paper, because it traps a lot of air, which is a good thermal insulator.)
Owner: Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder
Contributors: Xochitl Zamora-Thompson, Sabre Duren, Jeff Lyng, Malinda Schaefer Zarske, Denise Carlson
Copyright: ©2005 by Regents of the University of Colorado
Filed under: Grades K-5, Lesson Plans
Tags: Lesson Plan, Solar Engineering
