An Arctic Solar Shelter An Arctic Solar Shelter Design ChallengeDesign Challenge

Integrating the Integrating the Engineering Design Process Engineering Design Process

into a study of the Arctic Regioninto a study of the Arctic Region

STEM

Kotzebue, Alaska is located 33 miles Kotzebue, Alaska is located 33 miles north of the Arctic Circlenorth of the Arctic Circle

You can learn more about Kotzebue You can learn more about Kotzebue by visiting their web siteby visiting their web site.

http://kotzpdweb.tripod.com/city/index.html

An Aerial View Of Kotzebue

http://en.wikipedia.org/wiki/Kotzebue,_Alaska

Students in that community attend Students in that community attend the Kotzebue Middle/High Schoolthe Kotzebue Middle/High School

Visit the school’s web site at:Visit the school’s web site at:

http://www.nwarctic.org/Schools/kmhs/index.htm

20 days of sunlight20 days of sunlight

Because Kotzebue is just north of the Because Kotzebue is just north of the Arctic Circle,Arctic Circle, there are 20 days each year here are 20 days each year when there are 24 hours of daylight. when there are 24 hours of daylight.

The summer solstice is in the middle of that The summer solstice is in the middle of that 20 day period. 20 day period.

Would it be possible to take advantage of Would it be possible to take advantage of that 24 hours of sunlight to heat a shelter for that 24 hours of sunlight to heat a shelter for Arctic researchers?Arctic researchers?

The Arctic Solar ChallengeThe Arctic Solar Challenge

Design, build, and evaluate Design, build, and evaluate the performance of a portable, the performance of a portable, temporary, passive solar temporary, passive solar structure that can be used as a structure that can be used as a shelter for researchers who will shelter for researchers who will be in Kotzebue, Alaska around be in Kotzebue, Alaska around the time of a summer solstice.the time of a summer solstice.

.

In the Arctic Region, there is an interesting In the Arctic Region, there is an interesting “window of opportunity” for a passive solar collector “window of opportunity” for a passive solar collector

in terms the number of hours of daytime.in terms the number of hours of daytime.

http://www.eoearth.org/article/Earth-Sun_relationships_and_insolation

There is also a window of opportunity in There is also a window of opportunity in terms of solar insolation.terms of solar insolation.

http://www.eoearth.org/article/Earth-Sun_relationships_and_insolation

Materials you can use to build a Materials you can use to build a model of a solar shelter include:model of a solar shelter include:

• A photocopier paper boxA photocopier paper box

• Transparent window materialTransparent window material

• Reflective FoilReflective Foil

• Paper of different colorsPaper of different colors

• ScissorsScissors

• Insulating MaterialsInsulating Materials

• Other Easily Obtained MaterialsOther Easily Obtained Materials

The Engineering Design Cycle is one way to describe The Engineering Design Cycle is one way to describe the process of designing, building, and evaluating the the process of designing, building, and evaluating the

performance of a model of an Arctic solar shelter.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 Designing and building a passive solar shelter provides an opportunity to evaluate how provides an opportunity to evaluate how energy is transmitted and transformed.energy is transmitted and transformed.

• Visible light and near infrared energy Visible light and near infrared energy radiatesradiates from the sun and passes though from the sun and passes though windows of a passive solar collector and can windows of a passive solar collector and can be transformed into heat (thermal energy).be transformed into heat (thermal energy).

• Heat is Heat is conductedconducted through the walls of a through the walls of a structure from a warmer environment to a structure from a warmer environment to a colder environment. colder environment.

• ConvectionConvection currents will form as air inside a currents will form as air inside a building expands and rises as it is heated or building expands and rises as it is heated or compresses and sinks as it cools.compresses and sinks as it cools.

The angle of incidence of The angle of incidence of radiatedradiated sunlight entering sunlight entering a window changes as the seasons change and also a window changes as the seasons change and also depends on Latitude. The angle of incidence is also depends on Latitude. The angle of incidence is also

called the “called the “altitudealtitude” of the sun.” of the sun.

http://www.azsolarcenter.com/design/pas-2.html

You can design the location of windows so that You can design the location of windows so that the maximum amount of sunlight enters the the maximum amount of sunlight enters the

structure and is converted into heat.structure and is converted into heat.

.

Insulating materials selected for your model of a Insulating materials selected for your model of a shelter will reduce the loss of heat by conduction. The shelter will reduce the loss of heat by conduction. The value of those materials depend on value of those materials depend on

The thickness of the insulating material The thickness of the insulating material The type of insulating material The type of insulating material Strategies used to insulate windows when there is Strategies used to insulate windows when there is little or no solar gain little or no solar gain

T2                                              T1       

http://sol.sci.uop.edu/~jfalward/heattransfer/heattransfer.html

Even igloos have insulated walls. Even igloos have insulated walls. Air spaces in the blocks of snow reduce Air spaces in the blocks of snow reduce

the reduce the rate at which energy is the reduce the rate at which energy is conducted though the walls.conducted though the walls.

http://en.wikipedia.org/wiki/Igloo

You also need to manage the flow of air into You also need to manage the flow of air into and out of your model of a polar solar shelter.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!Some igloos are built to manage convection! Entryways of many igloos are designed to be Entryways of many igloos are designed to be

lower that the elevated sleeping area.lower that the elevated sleeping area.

http://en.wikipedia.org/wiki/Igloo

Design a Valid Test.Design a Valid Test.

You need to simulate the conditions You need to simulate the conditions that polar researchers experience in that polar researchers experience in Kotzebue, Alaska when you collect Kotzebue, Alaska when you collect data with your model of a Arctic solar data with your model of a Arctic solar collectorcollector.

For today’s weather in Kotzebue visit:

http://www.wunderground.com/US/AK/Kotzebue.html

The angle of incidence of sunlight The angle of incidence of sunlight is one factor to consider when is one factor to consider when

designing a fair test of your Arctic designing a fair test of your Arctic solar collector.solar collector.

The maximum angle of incidence The maximum angle of incidence of sunlight entering your passive of sunlight entering your passive solar collector needs to be similar solar collector needs to be similar to the maximum angle of incidence to the maximum angle of incidence of sunlight in Kotzebueof sunlight in Kotzebue..

The midday sun in KotzebueThe midday sun in Kotzebue The highest altitude of the sun in Kotzebue on the The highest altitude of the sun in Kotzebue on the

first day of summer is 46.5first day of summer is 46.5º.º.

The U.S. Naval Observatory web site provides The U.S. Naval Observatory web site provides

the sun’s altitude data for any location.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 The midday altitude of the sun is also approximately 46approximately 46º F on the following º F on the following

dates at the following locationsdates at the following locations..

• In Corpus Christie, TX on February 5thIn Corpus Christie, TX on February 5th• In Charlotte, NC and Flagstaff, AZ on February In Charlotte, NC and Flagstaff, AZ on February

27th27th• In Columbia, MO on March 7thIn Columbia, MO on March 7th• In New York City and Redding, CA on March 12thIn New York City and Redding, CA on March 12th• In Detroit, MI and Boston, MA on March 17In Detroit, MI and Boston, MA on March 17thth

These dates would occur during a time These dates would occur during a time periods when a test of a design of a polar solar periods when a test of a design of a polar solar shelter could be conducted.shelter could be conducted.

.

Average daily temperatures are also an Average daily temperatures are also an important factor when evaluating the important factor when evaluating the

performance of a model Arctic solar shelter.performance of a model Arctic solar shelter.

Between the summer solstice and the Between the summer solstice and the middle of August, average high temperatures middle of August, average high temperatures in Kotzebue range from 50in Kotzebue range from 50º F to 6º F to 600º F. The º F. The daily low temperatures range from 3daily low temperatures range from 300º F to º F to 5500º F.º F.

A NOAA web site can be used to compare early A NOAA web site can be used to compare early summer temperatures in Kotzebue with summer temperatures in Kotzebue with

other locations at other times of the year.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 This web site provides an animation that can be used to evaluate how the “sunshine factor” be used to evaluate how the “sunshine factor”

affects the window of opportunity for using affects the window of opportunity for using a passive solar collector in the Arctic Region.a passive solar collector in the Arctic Region.

http://www.fao.org/WAICENT/FAOINFO/SUSTDEV/EIdirect/climate/EIsp0002.htm

Other factors to consider when Other factors to consider when determining the fairness of the test determining the fairness of the test of the performance of a model of an of the performance of a model of an

Arctic solar shelter include:Arctic solar shelter include:

• TopographyTopography

• Wind direction and speedWind direction and speed

• Ground temperatureGround temperature

• Any other factors?Any other factors?

A series of tests of the performance of a model of an A series of tests of the performance of a model of an Arctic solar shelter also provides an opportunity to Arctic solar shelter also provides an opportunity to evaluate relationships among scientific variables.evaluate relationships among scientific variables.

• Controlled variables remain constant from one trial Controlled variables remain constant from one trial to the next. Examples include the angle of incidence to the next. Examples include the angle of incidence of sunlight and outside temperatures.of sunlight and outside temperatures.

• An independent variable changes from one trial to An independent variable changes from one trial to the next. An example would be the thickness of the next. An example would be the thickness of insulation in the floor, walls, and roof.insulation in the floor, walls, and roof.

• A dependent variable is one that depends on a value A dependent variable is one that depends on a value of an independent variable. An example would be of an independent variable. An example would be changes in the shelter’s temperature that results changes in the shelter’s temperature that results from a change in the thickness of insulationfrom a change in the thickness of insulation.

Lower Latitude applications of designing Lower Latitude applications of designing a passive solar Arctic shelter include:a passive solar Arctic shelter include:

• Describing how your design can be Describing how your design can be adapted for use in your region in either adapted for use in your region in either cooling or heating seasons.cooling or heating seasons.

• Determining the passive solar potential Determining the passive solar potential of your school building.of your school building.

• Evaluating the ecological advantages Evaluating the ecological advantages of passive solar structures.of passive solar structures.