Thermal Technology

							Thermal Technology
1.   Use computers and calculators to access, retrieve, organize, process,
     maintain, interpret, and evaluate data and information in order to
     communicate. (ITEA, STL 12-P).
2.   Document processes and procedures and communicate them to different
     audiences using appropriate oral and written techniques. (ITEA, STL 12-L)
3.   Identify and describe applications of thermal technology in the designed
     world such as thermometer, refrigerator, furnace, air conditioner, and heat
     engines.
4.   Explain science concepts and mathematical concepts applied in thermal
     technology such as convection, conduction, radiation, insulation, and
     efficiency.
Engineering, the systematic application of

  mathematical, scientific, and technical principles,

  produces tangible end products that meet our

  needs and desires.
• To familiarize students with the functioning and
  applications of thermal technology systems by
  having them analyze the functioning of thermal
  systems in terms of their common components,
  basic system design, safety considerations, and
  simple controls.
• Student groups will investigate one of the properties of heat energy
   using the following apparatus:
    – cup painted white, cup painted black, graduated cylinder, water, two
       thermometers, incandescent light (100W lamp), measuring tape or ruler,
       clock.

• Students will use the graduated cylinder to measure an equal
   amount of water into both containers so that they are about half
   full.
• Students will measure the temperature of the water in each
   container and record these temperatures as the temperatures at
   time zero minutes.
• Students will set the light so that it is the same distance from each
   container. Turn the lamp on and start the timer. After one minute,
   measure and record the temperature in each container.

• Continue to measure and record the temperature of each container
   every minute for ten minutes.

• Students will use a spreadsheet program to organize their data

• Students will construct a graph of time vs. temperature for their
   investigation. Plot the data from each container on the same graph
   using a different color for each container.
Time   Temp (white cup)   Temp (black cup)
 0
 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
Make a graph using Microsoft Excel
       Answer these Questions…..
1. Which container showed the greater increase in temperature?
2. Which container absorbed more energy and how do you know this?
3. What was the source of heat in this experiment?
4. What were the controlled factors in this experiment?
5. Why was it important to keep these factors the same for both containers?
6. If you were going to use radiant energy from the sun to heat your home, what colors
   would be best to use? Explain your answer.
7. If the containers used in this experiment were filled with hot
  water, which one do you think would cool off more slowly?
  Explain your answer.
8. Describe an experiment that you could do to test your

  hypothesis.
     HOMEWORK

• Bring in a recycled 3 panel display board from
  your Science Fair project, or a large flat sheet of
  cardboard at least 3’ x 4’.



• You can check with your science teacher to see if
  they have some left from the science fair.
         Thermal Technology –
• The technology of producing,
  storing, controlling, transmitting and
  getting work from heat energy.


•Example applications: furnace, hot water
heater, toaster, insulation, heat exchanger,
refrigerator, jet engine, hot air balloon.
A. The universe is made up of matter and
   energy.
B. Matter is made up of atoms and molecules
   (groupings of atoms)
- energy causes the atoms and molecules to always be in
   motion—either bumping into each other or vibrating back
   and forth.

C. The motion of atoms and molecules creates
   a form of energy called heat (or thermal
   energy) that is present in all matter.
D. Thermodynamics is the science
  dealing with internal energy, heat,
  and work.

E. Even in the coldest voids of
   space, matter has a very small
   but still measurable amount of
   heat energy.

F. Energy can take on many forms
   and can change from one form to
   another.
G. Many different types of energy can be converted into
   heat energy:
   -Light, electrical, mechanical, chemical, nuclear, sound,
   and thermal energy can each cause a substance to heat
   up by increasing the speed of its molecules.



H. Put energy into a system and it heats up; take energy
   away and it cools.
-(For example, when we are cold, we can jump up and down to get warmer.)
  A few examples of various types of energy being converted into
                  thermal energy (heat) including:
1. Mechanical energy is converted into thermal energy whenever
  you bounce a ball.
2. Electrical energy is converted into thermal energy
   - electrical stove elements, toasters, hair dryers, or light bulbs.
3. Chemical energy from the foods we eat is converted into
  heating our bodies.
4. Light from the sun is converted to heat as the sun’s rays warm
  the earth’s surface.
Heat can be transferred from
one place to another by three
methods:


1. conduction in solids
2. convection of fluids (liquids or gases)
3. radiation through anything that will allow
  radiation to pass.
1. Thermal resistance is a measure of an object’s ability to oppose
  heat transfer.
2. Materials with high thermal resistance are used to insulate an
  object or a region of space.

Walls are often constructed of layers of
materials of varying thermal conductivity.
(A house wall may consist of a layer of half-inch
sheetrock, a layer of three inch thick insulation,
and an outer layer of brick four inches thick.)
       Calculate the thermal resistance
1/2” - Sheetrock   3” - Insulations   4” - Brick

                                          Material             Thermal
                                                             Conductivity
                                                                 Btu • ft2• °F
                                       Sheetrock                     5.2
                                       Insulation                   0.32
                                       Brick                         408
             The area of the wall is equal to 300 sq ft.

    Calculate the thermal resistance (R) of each layer, where:

                        thickness of material (in)
           R=       thermal conductivity x area of wall

                   Rtotal= R1 + R2 + R3
            thickness of material (in)
R=      thermal conductivity x area of wall


                0.5 in                                 h · °F
R1=                                   =    0.00032
             5.2 x 300 ft2                             BTU

R2=             3 in              =       0.031    h · °F
            .32 x 300 ft2                          BTU

                4 in                 =    0.0028     h · °F
 R3=        4.8 x 300 ft2                            BTU


                                          0.034    h · °F
     Rtotal= R1 + R2 + R3        =                 BTU
              Construct a Solar Collecting House


1. Determine which insulating material holds
   heat the best.
    a) All material must be 1/2 inch thick.
    b) Must cover all walls and floor.
    c) A closed 7 ½”” x 10 1/2” window will
        be used to allow light to heat the
        interior for 10 minutes.
    d) You choose your own colors.
2. Record data and represent it in graph form.
                           14 inches




Window opening will be 7                   12 inch equal
 1/2” x 10 1/2” centered               lateral triangle sides
Something to Consider….
Conducting the experiment:
1. Record the starting temperature of the Solar House.
2. Heat the Solar House for 10 minutes.
3. Record the temperature drop without any lining materials. (this
  provides a set of data to compare your linings to)
4. Line the Solar House with the material selected and measure the
  temperature every 30 seconds during the heating and cooling
  stages. Repeat this process twice and average the results.
5. After the data has been collected, recorded the results on a chart
  and displayed in a graph.