A. The Greenhouse Effect
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1. Objective—observe the Greenhouse Effect.
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2. Additional materials—thermometer.
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3. Procedure:
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a. Measure and record the outside temperature.
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b. Insert the thermometer through the back wall of the model, face model toward sun and record the temperature every 5 minutes for 15 minutes.
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c. Prepare a simple graph with temperature (degrees on one aide and time (minutes) on the other aide as shown below. Plot the temperature readings and then connect the dots with a continuous line.
(figure available in print form)
B. Absorbing Heat with Light and Dark Surfaces
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1. Objective—measure heat-absorbing properties of different colored surfaces.
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2. Additional materials—white and black matboard floor cover, thermometer.
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3. Procedure:
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a. Orient the model toward the sun, and insert white-side matboard on the floor. Place the thermometer inside.
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b. Measure and record the temperature every 5 minutes for 15 minutes.
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c. Reverse the matboard on the floor to the black aide. Again, place the thermometer on the floor and measure and record the temperature every 5 minutes for 15 minutes.
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d. Compare readings on the dark and light surfaces.
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e. Different colors may be placed on the floor and temperatures recorded to determine what colors have higher heat-absorbing qualities. Shiny and dull surface may be compared.
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4. Observations:
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a. What color surfaces absorb the most heat?
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b. Ii you were putting a floor in a house near a south facing window to absorb heat, what colors might you select?
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c. Are the temperatures in the house too warm for comfortable living? If so, what can be done to lower the temperatures during the day?
C. Storage Mass
Storage mass (thermal mass), usually in the form of water in containers, masonry floors and walls, or rock storage bins, are used in passive solar houses to store heat during the day and emit it into the living apace at night. Storage mass also is used to regulate heat within the space so that it is not too hot during the day or too cold at night.
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1. Objective—determine how solar mass may be used to store heat.
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2. Additional materials—thermometer, white and black matboard floor cover, black water container,
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3. Procedure:
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a. Orient the model toward the sun with black floor cover in place.
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b. Place the thermometer on the black floor cover.
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c. Measure and record the temperature every 5 minutes for 20 minutes.
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d. Place the model in the shade and record the temperature every 5 minutes for another 20 minutes,
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e. Open the back section of the model and allow it to cool to normal temperature.
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f. Fill the container with water and set it inside the model near the window. Orient the model toward the sun.
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g. Again, measure and record the temperature every 5 minutes for another 20 minutes.
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h. Carefully place the model in the shade and record the temperature every 5 minutes for another 20 minutes .
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i. Other experiments may be conducted by filling the container with small pebbles or sand instead of water and repeating each of the above procedures.
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4. Conclusions:
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a. What effect does storage mass have on daytime temperatures?
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b. How is the temperature changed after the house has been placed in the shade?
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c. How would you apply your observations to the construction of a passive solar greenhouse?
D. Insulation
The large areas of south-facing glazing on a passive solar greenhouse create a large amount of heat loss during the night, Many greenhouses use moveable insulation in the form of curtains or panels.
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1. Objective—to determine the effect of moveable insulation in retaining heat.
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2. Additional materials—thermometer, water container, insulation panel (white and black matboard).
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3. Procedure:
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a. Place the model in the shade with the thermometer inside,
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b. Fill the water container with hot water. Record the temperature of the water and place the container inside the model,
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c. Measure and record the temperature in the model after 30 minutes.
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d. Remove and empty the water container,
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e. Repeat step b, The water should be the same temperature,
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f. Place the insulation panel over the plastic window glazing and repeat step c.
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4. Conclusion:
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a. How effective is the insulation panel?
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b. How can you make the model solar greenhouse more energy-efficient?
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c. What can be done to better insulate your model solar greenhouse?
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(figure available in print form)
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(figure available in print form)
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(figure available in print form)
(figure available in print form)
