Build a Passive Solar House
by Robin Hegg
Smart buildings use technology to make our indoor environments as energy efficient and comfortable as possible. But a building’s initial design can have a major impact on energy efficiency. In this activity, you will design and build a passive solar house. Passive design uses no mechanical or electrical devices of any kind, but uses design, orientation, and carefully selected materials instead. Designing an energy-efficient home means making optimal use of the natural heating power of the sun.
Passive solar design uses different materials and design elements to keep a building cool during the summer and warm in the winter. It also makes use of the sun’s angle in the sky at different times of the day and of the year through a building’s placement, the placement of windows and doors, and materials that can absorb or reflect the sun’s heat.
If you’re doing this activity when it is cooler outside, your house will need to use the sun to heat the inside of the house. If you’re doing this activity when it’s warmer outside, the house will be built to limit temperature increase.
Your house must include four walls, a roof, two working doors, and a window. It should be at least 15 cm high with an area of at least 30 cm. You’ll need to leave room inside for a thermometer to be placed so temperatures can be recorded.
Cardboard or cereal boxes
Light and dark tempera paint
Thermometer or temperature strips
1. Using what you know about the sun’s position, heat absorption and reflection, and what you’ve learned about smart buildings and passive solar design, design your solar house. Think about what materials and colors you will use and remember to think about how you will position your house in relation to the sun. If you want more information on the sun’s angle, check out http://www.susdesign.com/sunangle.
2. Construct your house using the materials available. Include a window. You will use the window to view the thermometer. Use plastic wrap to seal the window.
3. Place your house outside at midday. Use a compass to make sure your house is placed in the position you planned.
4. Place a thermometer inside your house and record its starting temperature. Continue to test and record the internal temperature of your house every 2 minutes for 12 minutes.
5. Move your house to a shaded area and test the temperature every 2 minutes for another 12 minutes.
6. If you have time, open your house’s window by removing the plastic wrap and repeat step 5 to test the temperature again. Compare the results.
1. Did your solar house successfully increase the internal temperature or keep it cool (depending on the time of year)?
2. What materials do you think were most helpful to your house’s design?
3. What materials outside of those that were available do you think would have helped your house to better cool or heat itself?
4. Having tested your house, would you change your design? What design or material changes do you think would help your house to work better?
5. If you were to turn your passive solar house into a smart house, what features would you add? How do you think smart building technology could help to make even better use of the sun’s energy?