National Science Standards

Science as Inquiry: Content Standard A:
All students should develop:

Abilities to do scientific inquiry
Identify questions and concepts that guide scientific investigations
Design and conduct scientific investigations
Use technology and mathematics to improve investigations and communications
Formulate and revise scientific explanations and models using logic and evidence
Recognize and analyze alternative explanations and models
Communicate and defend a scientific argument

Physical Science: Content Standard B:
All students should develop an understanding of:

Conservation of energy and increase in disorder
Interactions of energy and matter
Life Science: Content Strand C: All students should develop an understanding of
Matter, energy, and organization in living systems

Earth and Space Science: Content Strand D:
All students should develop an understanding of:

Energy in the earth system

Science and Technology: Content Standard E:
All students should develop:

Abilities of technological design
Understanding about science and technology

Science in Personal and Social Perspectives: Content Standard F:
All students should develop understanding of:

Environmental quality

Learning Objectives

Each student will:

Explain how heat transfer mechanisms (conduction, convection and radiation) and infiltration specifically influence the building envelope.
Give examples of how the building envelope can be improved using an understanding of heat transfer mechanisms.
Make and test hypotheses about building envelope design and heat transfer mechanisms.

Background Information, Vocabulary and Materials

Background Information

In Lesson 1, we used a shipwrecked situation to construct a simple shelter. What we were trying to deal with was in fact heat and moisture transfer into and out of our structure.

In Lesson 2, we defined the structure itself, calling it the building envelope system that includes subsystems of floor(s), walls, doors, windows, ceiling(s) and roof(s). We then discussed how heat is either lost or gained through these building envelope components through three heat transfer methods: conduction, convection and radiation. We also introduced infiltration and how it can bring in or remove hot or cold air and moisture.

Now, in Lesson 3, we will take two 50-minute class periods to investigate improving comfort and productivity in our buildings by looking at how we can improve the building envelope (how we can improve the building’s floor(s), walls, doors, windows, ceiling(s) and roof(s)). Improving the envelope means we are reducing or limiting conduction, convection and radiation and controlling infiltration through the envelope components. These reductions in heat transfer and uncontrolled airflow will in turn improve comfort and productivity in buildings; this entire process can be thought of as improving building performance.

Lesson 3 revolves around lab experiments that illustrate heat transfer methods (Conduction Activities, Convection Activities and Radiation Activities). Make sure to relate the results back to real buildings (e.g. your school or house) and building performance.

You will also be using the EnergyGauge USA^® software to show how annual energy use and cost decreases as the building envelope is improved and infiltration is reduced. Review the Efficient Envelope home on the software for your climate, especially noting the differences in the insulation levels (between the Base home and Efficient Envelope home) for the ceiling, walls, windows and floor, and Infiltration screen Estimated Envelope Tightness. Note that the values used for the Efficient Envelope house are typical of well insulated homes for the climate.

One other note here is that a well insulated home in the South (of the United States) does not require as much insulation as a well insulated home in the North. This is because temperature differences between indoors and outdoors during the winter are generally significantly greater in the North than in the South. This concept is discussed in greater detail in the optional Advanced Conduction Activities lesson.

If time permits and it’s desired, you can add an extra day to discuss lab results, test some optional insulating or reflective materials and/or spend more time working with the software.

Vocabulary

Building Performance

Materials

Lab and other experimental equipment as called for in the Convection, Radiation and Conduction Activities labs.

Lesson Procedures

Presenting the Information

Have students hand in their heat transfer mechanism homework from last class
(if assigned) and then discuss some of their examples.

Explain that for this class period and the next, the class will be conducting a series of 3 sets of experimental activities to investigate each of the 3 heat transfer mechanisms.

Student Practice/Activity

Conduction Activities:
Refer to Conductive Heat Transfer Experiments. Experiment should take approximately 20 minutes if set up before class.

Convection Activities:
Refer to Convection Heat Transfer Experiments. Experiment should take approximately 20 minutes if set up before class.

Radiation Activities:
Refer to Using Radiant Barriers to Learn About Radiation. Experiment should take approximately 30 minutes if set up before class.

Discuss your results using the questions and suggestions in each of the labs. Help students see that what we are typically doing in adding insulation or installing a radiant barrier is reducing the rate at which one or more heat transfer mechanisms are occurring.

Also refer back to the Stranded! activity. The Lesson 3 labs should have given them a better understanding of why some design options were better than others.

Finally, run the EnergyGauge Student Edition Base home for your climate again to review the estimated annual energy use you calculated during Lesson 2. Then run the Efficient Envelope home that has high levels of insulation, better windows, better doors and lower infiltration to see how much the annual energy use is reduced. Then starting with the Base home again, run each improvement separately (e.g. run Base home after changing the ceiling insulation from R-1 to R-19, then to R-45; then change wall insulation…) to see how the improvements change the building energy use (have the students keep track energy use and energy cost reductions). Alternatively, as a contest or more informally, have students guess which improvements will produce the greatest benefits. Discuss your results, tying in how the improvements are reducing conductive, convective and/or radiative heat transfer to or from the home.

Feedback

Take several minutes to review Advance Organizer slide number four (Improving the Building Envelope), and answer any questions. Discuss how the Lesson 3 activities might be applied to the “stranded hut”. Tell students that the next lesson will be on Additional Improvements (HVAC) and (optionally) assign “history of air conditioning” web research homework (as described below in the next section).

Handouts and Worksheets

Supply lab activity instructions to students.
[Optional homework for Lesson 4] Find a web site with information on the history of air conditioning. Read the information, print the web page and bring it to class.

Two example sites are:
ARI History of air conditioning web site at
http://www.ari.org/consumer/history/history-ac.html

“About” History of air conditioning web site at
http://inventors.about.com/library/weekly/aa081797.htm

Criterion-Referenced Test

This material part of final test. See Testing Blueprint in Teacher's Guide for details.

Individual pages from this web site may be printed and duplicated for
student classroom use provided that proper credit is given to
the Florida Solar Energy Center (FSEC).