Solar Oven/ Heating a Home

  • Can an oven be made using the sun?
  • What properties improve or hinder oven performance?
  • How long does it take for the oven to heat up?
  • What conditions might affect the oven’s heating time?

Side Idea:

  • Could the idea be modified and used to heat a home?

Recommended Items:

  • Paint
  • Cardboard
  • Newspaper
  • Plastic

Concepts used:

  • Insulation, Reflection, Radiative heating

Background:

The sun is a natural source of energy and a great source of heat. The sun’s energy can be trapped or guided to heat objects. Different materials can heat faster when they are exposed to the sun than do other materials. For example, leather seats in a car are hotter to the touch than fabric seats. Also, different colors will absorb light more efficiently (reflect less light), than other colors and this will result in more efficient heating of an object (faster and hotter heating). When heating an enclosed area, like a home or a solar oven, the absorption of solar radiation (light) can be used to raise the temperature inside the enclosure. An important consideration when heating an enclosed area is the effect of insulation on the temperature achievable in the enclosure in order to prevent heat from escaping. Different wall thicknesses or types of insulation in the walls of a structure will impact the amount of heating that can be achieved. Mirrors can also be used to reflect light into the enclosure in order to increase the amount of light used to heat the interior area.

This experiment uses the sun’s energy to make an oven for cooking food. A solar oven is a box with a clear window that allows sunlight to enter the box and heat the inside while preventing the inside from cooling. Before the oven is constructed, a few tests can be run to determine what materials to use. For example, the color of the cardboard or paper that is used to make the oven walls will have a big effect on how hot the solar oven gets inside. In order to test types and colors of paper, paint a square of paper a color and leave it out in the sun with a thermometer under it to see what temperature is reached. Do this for other colors and pick the hottest temperature color for the oven. Also when the oven is constructed, different amounts of insulation will effect heating. Experiment with amounts and different types of insulation to see what works the best. Finally, since more sunlight will lead to more heat in the oven, an interesting idea is to experiment with reflectors to see if it is possible to increase the amount of sunlight collected to heat the oven.

In the modified experiment, take a sunny house window and cover it with cardboard (leave an air gap between the cardboard and window) Paint the inside of the cardboard and try using different thicknesses of cardboard. Record the temperature at different areas, bottom, middle and top of the window area to observe the effect of color on temperature.

Read More:

http://www.ehow.com/how_2083_make-solar-oven.html

http://www.eia.doe.gov/kids/energy.cfm?page=solar_home-basics