STEM An Arctic Solar Shelter Design Challenge Integrating the Engineering Design Process into a study of the Arctic Region Kotzebue, Alaska is located 33 miles north of the Arctic Circle You can learn more about Kotzebue by visiting their web site. http://kotzpdweb.tripod.com/city/index.html Students in that community attend the Kotzebue Middle/High School Visit the school’s web site at: http://www.nwarctic.org/Schools/kmhs/index.htm 20 days of sunlight Because Kotzebue is just north of the Arctic Circle, there are 20 days each year when there are 24 hours of daylight. The summer solstice is in the middle of that 20 day period. Would it be possible to take advantage of that 24 hours of sunlight to heat a shelter for Arctic researchers? The Arctic Solar Challenge Design, build, and evaluate the performance of a portable, temporary, passive solar structure that can be used as a shelter for researchers who will be in Kotzebue, Alaska around the time of a summer solstice. . In the Arctic Region, there is an interesting “window of opportunity” for a passive solar collector in terms the number of hours of daytime. http://www.eoearth.org/article/Earth-Sun_relationships_and_insolation Materials you can use to build a model of a solar shelter include: • A photocopier paper box • Transparent window material • Reflective Foil • Paper of different colors • Scissors • Insulating Materials • Other Easily Obtained Materials The Engineering Design Cycle is one way to describe the process of designing, building, and evaluating the performance of a model of an Arctic solar shelter. Page 84 of the Massachusetts Science and Technology/Engineering Framework Designing and building a passive solar shelter provides an opportunity to evaluate how energy is transmitted and transformed. • Visible light and near infrared energy radiates from the sun and passes though windows of a passive solar collector and can be transformed into heat (thermal energy). • Heat is conducted through the walls of a structure from a warmer environment to a colder environment. • Convection currents will form as air inside a building expands and rises as it is heated or compresses and sinks as it cools. You can design the location of windows so that the maximum amount of sunlight enters the structure and is converted into heat. . Insulating materials selected for your model of a shelter will reduce the loss of heat by conduction. The value of those materials depend on The thickness of the insulating material The type of insulating material Strategies used to insulate windows when there is little or no solar gain T2 T1 http://sol.sci.uop.edu/~jfalward/heattransfer/heattransfer.html Even igloos have insulated walls. Air spaces in the blocks of snow reduce the reduce the rate at which energy is conducted though the walls. http://en.wikipedia.org/wiki/Igloo You also need to manage the flow of air into and out of your model of a polar solar shelter. http://www.azsolarcenter.com/technology/pas-3.html Some igloos are built to manage convection! Entryways of many igloos are designed to be lower that the elevated sleeping area. http://en.wikipedia.org/wiki/Igloo Design a Valid Test. You need to simulate the conditions that polar researchers experience in Kotzebue, Alaska when you collect data with your model of a Arctic solar collector. For today’s weather in Kotzebue visit: http://www.wunderground.com/US/AK/Kotzebue.html The angle of incidence of sunlight is one factor to consider when designing a fair test of your Arctic solar collector. The maximum angle of incidence of sunlight entering your passive solar collector needs to be similar to the maximum angle of incidence of sunlight in Kotzebue. The midday sun in Kotzebue The highest altitude of the sun in Kotzebue on the first day of summer is 46.5º. The U.S. Naval Observatory web site provides the sun’s altitude data for any location. . http://aa.usno.navy.mil/data/docs/AltAz.php The midday altitude of the sun is also approximately 46º F on the following dates at the following locations. • In Corpus Christie, TX on February 5th • In Charlotte, NC and Flagstaff, AZ on February 27th • In Columbia, MO on March 7th • In New York City and Redding, CA on March 12th • In Detroit, MI and Boston, MA on March 17th These dates would occur during a time periods when a test of a design of a polar solar shelter could be conducted. . Average daily temperatures are also an important factor when evaluating the performance of a model Arctic solar shelter. Between the summer solstice and the middle of August, average high temperatures in Kotzebue range from 50º F to 60º F. The daily low temperatures range from 30º F to 50º F. A NOAA web site can be used to compare early summer temperatures in Kotzebue with other locations at other times of the year. http://www.cdc.noaa.gov/USclimate/states.fast.html This web site provides an animation that can be used to evaluate how the “sunshine factor” affects the window of opportunity for using a passive solar collector in the Arctic Region. http://www.fao.org/WAICENT/FAOINFO/SUSTDEV/EIdirect/climate/EIsp0002.htm Other factors to consider when determining the fairness of the test of the performance of a model of an Arctic solar shelter include: • Topography • Wind direction and speed • Ground temperature • Any other factors? Lower Latitude applications of designing a passive solar Arctic shelter include: • Describing how the Arctic shelter design can be adapted for use in your region in either cooling or heating seasons. • Determining the passive solar potential of your school building. • Evaluating the advantages and limitations of passive solar structures.
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