Summary
This lesson explores conduction, convection, and radiation in
respect to insulation, the method of preventing heat from escaping a
container or entering a container.
Materials
Background for Teachers
This lesson explores conduction, convection, and radiation in
respect to insulation, the method of preventing heat from escaping a
container or entering a container. An understanding of conduction,
convection, and radiation are needed for optimal understanding of
these concepts.
As the students will engage in a group experiment, they will need
background in the scientific method. The steps in this method are ask
a question; gather background research; form a hypothesis; experiment;
analyze your data; draw conclusions; and record your results.
It is helpful if the students have already done several guided
experiments using this method in class. If not, differentiation should
be used to help those students who need more guidance, whereas more
advanced students may discover on their own.
Baby food jars and several insulation materials are needed for this
lesson. These include: down, gloves/mittens, cotton sock, wool sock,
other types of cloth or clothing, sand, plastic foam, dirt, large piece
of paper, foam packing peanuts, wood, aluminum foil, leaves, paper
towels, cardboard, cotton balls, shredded paper, fiberglass insulation,
etc. Collect them on your own before the experiment or have your
students bring in items easily accessible from home. If using fiberglass
insulation, you will need gloves so the material does not irritate the
skin.
The ability to transfer heat within an object is called thermal
conductivity. It varies for different materials. Gold, silver and copper
have high thermal conductivity so these materials are also good
conductors of electricity. Other materials, such as glass and mineral
wool, have low thermal conductivity. This quality makes them good insulators. A good insulator is a poor conductor. Less dense materials
are better insulators. Thus, gases insulate better than liquids, which in
turn insulate better than solids.
An interesting fact is that poor conductors of electricity are also
poor heat conductors.
Intended Learning Outcomes
1. Use science process and thinking skills
2. Manifest scientific attitudes and interests
Instructional Procedures
Invitation to Learn
Pass out a Which Uses More Energy? sheet to each student. Allow
between five and ten minutes for completion and journaling.
Instructional Procedures
- When students finish the invitation to learn, read each
energy question and allow students to raise their hands to
indicate their guess. Then read each correct answer and the
reasoning behind it. Discuss any surprises or reactions to
this information. Ask if the kids have any ideas of how we as
Americans can cut back on using energy.
- Introduce the term energy conservation (saving energy) in
relationship to heat. What do we do to stay warm outside on
a cold day? (wear a coat) How do we save money on heating
our homes in the winter? (appropriate insulation) What are
some examples of insulation? (animal fur, towel, blanket,
portable cooler, fiberglass, wool, foam, down, etc.)
- Insulators are materials that help prevent any of the three types
of heat transfer to keep heat in one place (either in or out).
This aids in energy conservation. Homes need insulation on
the roof for protection from the sun (radiation); on the floor to
protect from the cold ground (conduction); and on the walls to
protect from the wind (convection). A well insulated home will
not have wasted energy and will therefore not use as much heat
in the winter or air conditioning in the summer.
- Explain that the students are going to participate in an
experiment that explores different types of insulation. They will
select a material to insulate a jar of warm water and determine
whether or not it is a good insulator. Various insulation
materials are needed and should be set out prior to the lesson.
Fabrics should be labeled. You will need about 40 baby food
jars for this experiment. You may ask the students to bring
some materials from home.
- Students should be in groups of about four. Give each group a
copy of the Insulation Experimentation Planning Sheet to guide
preparations in their journals. Allow for differentiation when
appropriate; some students may be ready to plan an experiment
on their own and will not need the planning sheet. See that
all students are using their journals to record each step of the
scientific method.
- Before the students begin, discuss some of the following
questions: What are the variables in your project? (insulation
materials) How can you make sure to only test one variable?
(jars should be the same size; water should be the same amount
and initial temperature in each jar; all temperature readings
should be recorded at the same time) What time intervals
are appropriate for temperature testing? (I would suggest 1-3
minutes between each reading. Stopwatches may be used for
accuracy.) How will you record your observations? (tables,
graphs, report format) Where will you keep your jars?
(students may opt to take them outside if the temperature is
cooler)
- While the students are working, begin warming water in
microwave. Ensure it is hot, but not hot enough to burn
someone. You may also want to walk around to each group and
review how to read the thermometers. It is also helpful to pre-
cut small pieces of the Glad Press'n Seal Wrap for easy assembly
later.
- After forming a hypothesis, each student in the group should
surround a baby food jar or something similar with one type
of material, making sure to keep a small amount of the jar
available on top for sealing. Each jar should be the same size,
and each material should be different. If using dirt or sand, set
the baby food jar in the center of a small disposable container
and surround it with the selected material.
- When one or two jars per person are finished, use a measuring
syringe to fill each jar with 100 mL of water, or enough to
almost fill the jars you are using. Then place a thermometer
in each. Students should immediately record the temperature.
Seal with the Glad Press'n Seal Wrap while keeping the
thermometer in the jar for easy readings.
- One unsealed jar with a thermometer and no insulation should
act as the control. Timed temperature readings should be
recorded every few minutes. Observations should be recorded.
Pass out the Insulation Table and Insulation Graph to those who
need help recording their data.
- As the students are working, monitor student progress by
asking thought provoking questions that focus on student
understanding. Use the Insulation Experimentation Sample Table
& Graph as a tool to help guide your students' thinking.
- When students are finished, they should record and analyze
their data and draw conclusions to answer their question.
Remind them that all parts of the scientific method need to be
written up in their science journals.
- On day two, have a class discussion about the experiment.
Based on all data, which insulation was the best? Which was
the worst? Did any jars remain the same temperature? Share
differences in experimentation and data. At the conclusion of
your discussion, instruct the students to share their conclusions
in their journals, as well as write any questions they still wonder
about.
Extensions
Curriculum Extensions/Adaptations/
Integration
- Invite an HVAC (heating, ventilation, and air conditioning)
professional to explain how he/she knows how many radiators
or ducts are needed to heat a room.
- Challenge advanced students to research how insulation
techniques have changed over time, or how different societies
throughout history have heated their living environment.
- Research extreme temperatures throughout the world at
http://members.iinet.net.au/~jacob/worldtp.html and energy
conservation techniques used in those regions.
- Visit the Utah Energy Conservation Coalition website at www.
utahenergy.org to learn about energy conservation techniques
used in homes in Utah.
- Explore the concept of hypocausts, most likely
developed by the Ancient Romans, and how they were used.
You may also build a model of a hypocaust using bricks and
tiles. Simple instructions can be found at www.mylearning.org/learning/investigate-archaeology/Roman%20Central%20Heating.pdf
Family Connections
- Have students learn about the amount and type of insulation in
their own homes, including techniques used by their families
to stay warmer in the winter (i.e. plastic on windows, towels on
floor by doors, electric blankets, etc.).
- Have students and their families design and put into place an
energy conservation plan in their homes to save on energy bills.
Assessment Plan
- Hypothesize about what might happen if you tried the
experiment again, this time recording the temperature for a
longer amount of time (one, two, even three hours). Which materials might work better? Will there be a point when none
of the jars are insulated well enough to keep the water warm?
To assess a students' understanding of the scientific method and
the experiment done in class, have them write up how to set up
this experiment. If more time is available, try it!
- Remind the students that metals are excellent conductors of
heat. Based on your experiment, did that make them good or
poor insulators? Why? (Good conductors cannot be insulators
because conductors remove heat, not sustain it.)
- Could you design an experiment to measure keeping things
cool? Ask students to journal their ideas.
Bibliography
Research Basis
Osman, M., & Hannafin, M.J. (1994). Effects of advance organizing, questioning and prior
knowledge on science learning. Journal of Educational Research, 88(1), 5-13.
Good questioning requires skill and planning. Learning is
maximized in classes where questions are encouraged, elaboration
and explanation are expected, and feedback is frequent. Effective
science teachers ask many higher-lever thinking and follow-up
questions throughout a lesson. Better teacher questioning practices
lead to better learning by all students. The foundation to good
questioning is strong content knowledge and a firm understanding of
how students learn so that misunderstandings may be anticipated.
Chapman, C. & King, R. (2005). 11 Practical Ways to Guide Teachers Toward
Differentiation. ERIC Source (ERIC EJ752246). Retrieved December 17, 2007, from
http://www.eric.ed.gov
Differentiated learning takes student differences into account.
By focusing on the needs of the individual learner, students will do
better in school. Eleven steps are presented to help teachers move
toward a differentiated curriculum, including knowing the standards,
varying instructional strategies and activities, creating a positive
learning climate, providing a wide variety of materials, knowing the
students, and adjusting assignments when necessary.