1. Drill: How many times would an average car’s tires turn during a drive from downtown Baltimore to downtown Washington, DC? [What would you need to know? Explain your reasoning and show your work.] (Est. Distance, B’more to DC)/Tire Circumference=# of Rotations (40 miles)(5280 ft/mile)/ (2*1 ft) = 33,614 Rotations

2. Passive Solar Energy

3. Essential Questions  What is passive solar energy and how can it be used?

4. Passive Solar Energy The capture and use of solar energy w/o the aid of any moving mechanical systems.  Heating Homes  Cooking Roman BathhousesAnasazi PueblosModern Solar Home Solar Ovens

5. Solar Oven Design:  Solar Box Cookers  An insulating box with a glass cover to allow visible radiation to enter; solar energy is trapped within, raising the temperature  Solar Concentrating Cookers  Large mirrors or shiny surfaces are used to reflect and concentrate the sun’s rays onto a small volume, thus raising the temperature  Combination Designs  A combination of solar box and concentrating designs; concentrated sunlight is fed into a solar box, further increasing the heating potential

6. Solar Home Design:  Site Selection  Direct Gain  Indirect Gain  Control Strategies

7. Solar Home Design: Site Selection  In the northern hemisphere, the south side of a building always receives the most sunlight.  For the best designs, solar homes should have large south-facing windows.

8. Solar Home Design: Direct Gain  Sunlight that enters the home directly and is absorbed and temporarily stored in the floors or walls  Daylighting  Thermal Mass Let’s watch a video on Daylighting! Let’s watch a video on Thermal Mass!

9. Solar Home Design: Indirect Gain  Solar heat that is blocked from entering the home directly, but then is transferred from where it is collected and stored to different areas of the house  Trombe Wall  Sunspace  Solar Chimney  Thermosiphon

10. Solar Home Design: Control Strategies  Design elements that selectively block solar energy from entering or leaving the home.  Overhangs (Roof/Window)  Window Glazing  Blinds  Insulation Let’s watch a video on Cool roofs!

11. What’s Coming Up?  Active Solar Energy  Power Transmission  Impacts on Environment/Society