Solar Structures
This lesson focuses on how the sun’s energy can be used to heat and cool buildings. Teams of students construct passive solar houses from everyday materials. The houses will be tested for how well they keep warm or cool depending on the time of year.
- Design and build a passive solar house
- Test and refine their designs
- Communicate their design process and results
Age Levels: 8-18
Build Materials (For each team)
Required Materials
- Cardboard or cereal boxes
- Construction paper
- Plastic/Paper cups
- Sand
- Stones
- Plastic wrap
- Felt
- Light and dark color tempera paint
- Foliage
Testing Materials
- Compass
- Thermometer or temperature strips
- A sunny day
Materials
- Compass
- Thermometer or temperature strips
- A sunny day
Process
Test the solar house designs by placing each house in the sun (preferably midday) at the desired orientation (typically along the east west axis to take maximum advantage of the sun’s orientation) using a compass. Students should record the initial inside temperature of their house, and then again every 2 minutes for a total of 12 minutes. If time permits, they can then bring their house into the shade and record the temperature every 2 minutes for another 12 minutes.
- If the activity is being conducted during the cooler months, the goal is to increase and maintain the internal temperature of the house by as much as possible.
- If this activity is being conducted during the warmer months the object will be to limit temperature increase as much as possible.
Design Challenge
You are a team of engineers who have been given the challenge to design a passive solar house. The house must have 4 walls, at least four windows, 2 functional doors, and a roof. It must be at least 10cm high, 10cm wide and 25cm long. Your design must also include a way to hold a thermometer inside the structure so it can be easily read. Your house will be tested for how well it keeps warm or keeps cool depending on the time of year.
- For cooler months, the goal is to increase and maintain the internal temperature of the house by as much as possible.
- For warmer months, the object will be to limit temperature increase as much as possible.
Criteria
- Must have 4 walls, at least four windows, 2 functional doors and a roof.
- Must be at least 10cm high, 10cm wide and 25cm long.
- Design should include a way to hold a thermometer inside the structure.
Constraints
- Use only the materials provided.
Teams may trade unlimited materials.
- Break class into teams of 2-3.
- Hand out the Solar Structures worksheet, as well as some sheets of paper for sketching designs.
- Discuss the topics in the Background Concepts Section…highlight passive solar design. Consider asking students to share what they already know about green buildings. Discuss how engineering homes to make better use of renewable energy sources such as the sun can make homes more energy efficient and environmentally friendly.
- Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials.
- Instruct students to start brainstorming and sketching their designs.
- Provide each team with their materials.
- Explain that students must design and build a passive solar house. The house must have 4 walls, at least four windows, 2 functional doors, and a roof. It must be at least 10cm high, 10cm wide and 25cm long. Your design must also include a way to hold a thermometer inside the structure so it can be easily read.
• In cooler months, the goal is to increase and maintain the internal temperature of the house by as much as possible.
• In warmer months, the object will be to limit temperature increase as much as possible. - Announce the amount of time they have to design and build (1 hour recommended).
- Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
- Students meet and develop a plan for their solar house. They agree on materials they will need, write/draw their plan, and present their plan to the class. Teams may trade unlimited materials with other teams to develop their ideal parts list.
- Teams build their designs.
- Test the solar house designs by placing each solar house in the sun (preferably midday) at the desired orientation using a compass. Students should record the initial inside temperatures of their house, and then again every 2 minutes for a total of 12 minutes. If time permits, they can then bring their house into the shade and record the temperature every 2 minutes for another 12 minutes.
- As a class, discuss the student reflection questions.
- For more content on the topic, see the “Digging Deeper” section.
Student Reflection (engineering notebook)
- Did you succeed in creating a solar house that could increase and maintain its temperature or keep cool (depending on the time of year)? If not, why did it fail?
- Did you decide to revise your original design or request additional materials while in the construction phase? Why?
- Did you negotiate any material trades with other teams? How did that process work for you?
- If you could have had access to materials that were different than those provided, what would your team have requested? Why?
- Do you think that engineers have to adapt their original plans during the construction of systems or products? Why might they?
- If you had to do it all over again, how would your planned design change? Why?
- What designs or methods did you see other teams try that you thought worked well?
- Do you think you would have been able to complete this project easier if you were working alone? Explain…
- What advantages does passive solar building design have?
- What drawbacks does passive solar building design have?
Time Modification
The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.
Solar Building Design
Solar Energy
Solar energy is energy from sunlight. We can feel this energy as warmth when outside on a sunny day. Solar energy is a renewable source of energy, which means that it can be replenished by nature in a short period of time. Buildings can be designed to harness the power of the sun for heating and cooling purposes. This can be accomplished using active solar design, passive solar design, or a combination of both. Solar building designs are much more energy efficient resulting in structures with smaller carbon footprints that are much friendlier towards the environment.
Active Solar Design
Active solar design relies on the use of mechanical or electrical devices to convert sunlight into electricity, which can then be used to supply heat or power to a building. “Photovoltaics” refers to the field of science that is concerned with the application of solar cells to generate electricity for use by people. A solar cell is a small device that converts the sun’s energy into electricity. Solar cells create direct current, which can be used to power electrical devices. Solar cells can also be assembled into solar panels, which are being used more frequently in building design.
Passive Solar Design
Passive solar design on the other hand, involves selecting and placing design elements and materials to help keep a building warm during the winter months and cool during the summer months. Although a combination of both active and passive means may be utilized in solar building design, true passive solar design does not incorporate mechanical or electrical devices of any kind. Passive solar design is very cost effective for this reason. Passive solar design has been used for thousands of years. Ancient Greeks and Chinese built dwellings designed to take advantage of the sun’s warmth. Native Americans also used passive solar design elements when they built cliff dwellings. Solar design relies on the sun’s relative position in the sky to regulate the temperature inside a building. The angle of the sun’s rays at different times of the year must be analyzed when designing buildings according to the principles of passive solar design. Optimal building design will allow more sunlight to enter the building in the winter, retaining warmth, and less in the summer, keeping things cooler.
Passive Solar Design Elements
Passive solar design relies on several design elements. The orientation of the building itself is of particular importance. It is recommended that buildings be oriented along the east west axis to take maximum advantage of the sun’s orientation. Rooms that will be used the most are typically placed along the south side of the building. Rooms that are not used as frequently are placed along the north side of the building. Windows are another vital component of passive solar design as they allow sunlight to enter into a building. The optimal orientation for major windows in passive solar design is southern-facing. Windows on the north and west sides of the building should be minimized. Windows can also be treated with glazing materials to prevent heat loss.
When the sun shines through the windows of a building it needs a way to be stored. Materials known as thermal mass absorb and store the sun’s energy as heat for an extended period of time. In direct solar gain systems, thermal mass materials are part of the living space itself. Dark colored materials such as tile in walls or floors are quite effective at storing the sun’s heat. Therefore these materials help prevent large fluctuations in temperature which may be occurring outdoors. Thermal mass should be placed to get the most sunlight in winter but should be shaded during the summer.
Indirect solar gain systems involve the use of thermal mass in between the sun and the living space. These can include walls with insulating materials behind them, known as trombe walls, or rooftop water storage tanks. The heat from the sun is stored in these materials and transferred to the living area through convection and radiation respectively. Another technique known as isolated solar heating uses an area adjacent to the main living area called a sunspace (sunroom, solar greenhouse etc.), which collects the heat from the sun and then transfers it throughout the rest of the building.
A truly passive design uses only convection, radiation and conduction to distribute the heat. Devices such as fans, blowers and ducts can be integrated into the design to help distribute the heat, although they are considered to be active devices. To regulate the temperature of the building, electronic devices such as thermostats or blinds may also be used. When these types of devices are used it is sometimes known as “hybrid” heating.
Passive solar design also incorporates design elements that will keep a building cool especially during the summer. It is very important that there be a way for cool air to enter the building and hot air to exit the building. Vegetation, ponds and light colored surfaces around a building can help cool air as it enters. Features such as skylights and thermal chimneys can let hot air out of a building. When windows are southern facing, there is a potential for overheating during the summer months. Overhangs above the windows can help ensure that too much sunlight does not enter during the summer and that full sunlight can enter in the winter. Trees can also be helpful for providing shading during the summer months. Reflective materials beneath the roof can prevent too much heat from being absorbed from the sun. These design features will ensure that a passive solar building does not become too hot.
- Active Solar Design: Relies on the use of mechanical or electrical devices to convert sunlight into electricity, which can then be used to supply heat or power to a building.
- Constraints: Limitations with material, time, size of team, etc.
- Criteria: Conditions that the design must satisfy like its overall size, etc.
- Engineers: Inventors and problem-solvers of the world. Twenty-five major specialties are recognized in engineering (see infographic).
- Engineering Design Process: Process engineers use to solve problems.
- Engineering Habits of Mind (EHM): Six unique ways that engineers think.
- Iteration: Test & redesign is one iteration. Repeat (multiple iterations).
- Passive Solar Design: Involves selecting and placing design elements and materials to help keep a building warm during the winter months and cool during the summer months.
- Photovoltaics: Refers to the field of science that is concerned with the application of solar cells to generate electricity for use by people
- Prototype: A working model of the solution to be tested.
- Solar: Produced or made to work by the action of the sun’s light or heat solar energy.
- Solar cells: Make electricity directly from sunlight.
- Solar energy: Energy generated directly from sunlight.
- Solar panel: Made of solar cells, which is the part that turns the solar energy in sunlight into electricity.
- Thermal mass: Absorbs and stores the sun’s energy as heat for an extended period of time.
Internet Connections
Recommended Reading
- Passive Solar House: The Complete Guide to Heating and Cooling Your Home. (ISBN: 978-1933392035)
Writing Activity
Write a real estate advertisement marketing your passive solar house’s selling points.
Alignment to Curriculum Frameworks
Note: Lesson plans in this series are aligned to one or more of the following sets of standards:
- U.S. Science Education Standards (http://www.nap.edu/catalog.php?record_id=4962)
- U.S. Next Generation Science Standards (http://www.nextgenscience.org/)
- International Technology Education Association’s Standards for Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
- U.S. National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics (http://www.nctm.org/standards/content.aspx?id=16909)
- U.S. Common Core State Standards for Mathematics (http://www.corestandards.org/Math)
- Computer Science Teachers Association K-12 Computer Science Standards (http://csta.acm.org/Curriculum/sub/K12Standards.html)
National Science Education Standards Grades K-4 (ages 4 – 9)
CONTENT STANDARD A: Science as Inquiry
As a result of the activities, all students should develop
- Abilities necessary to do scientific inquiry
CONTENT STANDARD B: Physical Science
As a result of the activities, all students should develop an understanding of
- Properties of objects and materials
CONTENT STANDARD D: Earth and Space Science
As a result of the activities, all students should develop an understanding of
- Objects in the sky
- Changes in the earth and sky
CONTENT STANDARD E: Science and Technology
As a result of the activities, all students should develop
- Abilities of technological design
- Understanding about science and technology
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a result of the activities, all students should develop an understanding of
- Types of resources
- Changes in environments
National Science Education Standards Grades 5-8 (ages 10 – 14)
CONTENT STANDARD A: Science as Inquiry
As a result of activities, all students should develop
- Abilities necessary to do scientific inquiry
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop an understanding of
- Transfer of energy
CONTENT STANDARD D: Earth and Space Science
As a result of the activities, all students should develop an understanding of
- Structure of the earth system
CONTENT STANDARD E: Science and Technology
As a result of the activities, all students should develop
- Abilities of technological design
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a should develop an understanding of
- Populations, resources and environments
National Science Education Standards Grades 9-12 (ages 14-18)
CONTENT STANDARD A: Science as Inquiry
As a result of activities, all students should develop
- Abilities necessary to do scientific inquiry
CONTENT STANDARD B: Physical Science
As a result of their activities, all students should develop understanding of
- Interactions of energy and matter
CONTENT STANDARD D: Earth and Space Science
As a result of the activities, all students should develop an understanding of
- Energy in the earth system
CONTENT STANDARD E: Science and Technology
As a result of the activities, all students should develop
- Abilities of technological design
- Understanding about science and technology
CONTENT STANDARD F: Science in Personal and Social Perspectives
As a should develop an understanding of
- Natural resources
Next Generation Science Standards Grades 3-5 (Ages 8-11)
Energy
Students who demonstrate understanding can:
- MS-PS3-3. Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.
Engineering Design
Students who demonstrate understanding can:
- 3-5-ETS1-1.Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
- 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.
- 3-5-ETS1-3.Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
Next Generation Science Standards Grades 6-8 (Ages 11-14)
Engineering Design
Students who demonstrate understanding can:
- MS-ETS1-1 Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
- MS-ETS1-2 Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
Principles and Standards for School Mathematics
Measurement Standard
- Instructional programs from prekindergarten through grade 12 should enable all students to:
- Apply appropriate techniques, tools, and formulas to determine measurements.
Common Core State Standards for School Mathematics Grades 3-8 (ages 8-14)
Measurement and data
- Measure and estimate lengths in standard units.
- CCSS.Math.Content.2.MD.A.1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
- CCSS.Math.Content.2.MD.A.3 Estimate lengths using units of inches, feet, centimeters, and meters.
The Number System
- Apply and extend previous understandings of numbers to the system of rational numbers.
- CCSS.Math.Content.6.NS.C.5 Understand that positive and negative numbers are used together to describe quantities having opposite directions or values (e.g., temperature above/below zero, elevation above/below sea level, credits/debits, positive/negative electric charge); use positive and negative numbers to represent quantities in real-world contexts, explaining the meaning of 0 in each situation.
Standards for Technological Literacy – All Ages
Technology and Society
- Standard 5: Students will develop an understanding of the effects of technology on the environment.
Design
- Standard 8: Students will develop an understanding of the attributes of design.
- Standard 9: Students will develop an understanding of engineering design.
- Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.
The Designed World
- Standard 20: Students will be able to select and use construction technologies.
Industrial Engineering
Computer EngineeringDesign a Passive Solar House
You are a team of engineers who have been given the challenge to design a solar house. If the activity is being conducted during the cooler months, the goal is to increase and maintain the internal temperature of the house by as much as possible. If this activity is being conducted during the warmer months the object will be to limit temperature increase as much as possible. The house must have 4 walls, at least four windows and 2 functional doors, and a roof. It must be at least 10 cm high, 10 cm wide and 25 cm long. Your design must also include a way to hold the thermometer inside the structure so it can be easily read.
Planning Stage
Meet as a team and discuss the problem you need to solve. Then develop and agree on a design for your solar house. You’ll need to determine what materials you want to use.
Draw your design in the box below, and be sure to indicate the description and number of parts you plan to use. Present your design to the class.
You may choose to revise your teams’ plan after you receive feedback from class.
| Design: | |
|
|
Construction Phase
Build your solar house. During construction you may decide you need additional materials or that your design needs to change. This is ok – just make a new sketch and revise your materials list.
Testing Phase
Each team will test their solar house. Place your solar house in the sun at the orientation decided on by the team (use your compass). Use the thermometer to measure the internal temperature of your house every 3 minutes for 12 minutes. Then bring your house into the shade and measure the temperature every 3 minutes for another 12 minutes. Be sure to watch the tests of the other teams and observe how their different designs worked.
Evaluation Phase
Evaluate your teams’ results, complete the evaluation worksheet, and present your findings to the class.
1. Did you succeed in creating a solar house that could increase and maintain its temperature or keep cool (depending on the time of year)? If not, why did it fail?
2. Did you decide to revise your original design or request additional materials while in the construction phase? Why?
3. Did you negotiate any material trades with other teams? How did that process work for you?
4. If you could have had access to materials that were different than those provided, what would your team have requested? Why?
5. Do you think that engineers have to adapt their original plans during the construction of systems or products? Why might they?
6. If you had to do it all over again, how would your planned design change? Why?
7. What designs or methods did you see other teams try that you thought worked well?
8. Do you think you would have been able to complete this project easier if you were working alone? Explain…
9. What advantages does passive solar building design have?
10. What drawbacks does passive solar building design have?
Downloadable Student Certificate of Completion
