Maricopa Community Colleges  HVA110   19916-19982 
Official Course Description: MCCCD Approval: 04/23/91
HVA110 19916-19982 LEC 3 Credit(s) 3 Period(s)
Principles of Air Conditioning
Types and styles of cooling equipment and duct systems. Methods of supplying air to spaces for heating, cooling and heating-cooling. Velocities for specific situations. Heat pumps: their operation, controls and metering devices. Prerequisites: HVA105 or permission of department. Corequisites: HVA110LL or permission of department.
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MCCCD Official Course Competencies:
 
HVA110   19916-19982 Principles of Air Conditioning
1. Review the refrigeration cycle using the basic components and explain their functions. (I)
2. Explain the factors that lead to human comfort including the rate at which the body produces heat, body temperature, temperature-humidity relationships and type of clothing. (II)
3. Define specific terms used in psychometrics and coordinate points on the psychometric chart to conditions of a specific residence. (III)
4. List the components effecting cooling load and explain how they contribute to the total cooling load. (IV)
5. Identify the specific types and styles of cooling equipment. (V)
6. Explain the operation of major types of compressors used in air conditioning systems. (IV)
7. Identify and explain the operation of the fixed bore and thermostatic metering devices. (VII)
8. Explain purposes of forced-air systems and list the components. (VIII)
9. Explain duct system pressures, the unit in which the pressures are measured and describe the use of specific air measuring devices. (IX)
10. Identify the basic types of duct systems including, but not limited to: plenum, extended plenum, reduced plenum and perimeter loop. (X)
11. Compare and contrast the different duct materials and geometric configurations. (XI)
12. Describe the methods of supplying air to spaces for heating, cooling, heating-cooling and determine proper velocities in ducts for specific applications. (XII)
13. Identify and explain the operation of safety controls including thermostats, relays, contactors, high and low pressure controls, overloads and time delay relays. (XIII)
14. Explain the operation of the compressor starting component for Permanent Split Capacitor (PSC) motors. (XIV)
15. Compare and contrast operating conditions above/below design conditions. (XV)
16. Explain how a heat pump differs from an air conditioner. (XVI)
17. List the types of heat pumps and explain the heat source and the heat rejection medium. (XVII)
18. Explain the operation of metering devices including capillary tube, thermostatic expansion valve, electronic expansion valve and orifice metering devices. (XVIII)
19. Define terms associated with heat pumps including coefficient of performance, balance point, auxiliary heat and ambient temperature. (XIX)
20. Explain the operation of the controls used on heat pumps to include, but not limited to: low voltage thermostats, relays, heating controls, defrost timer and defrost termination thermostat. (XX)
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MCCCD Official Course Outline:
 
HVA110   19916-19982 Principles of Air Conditioning
    I. Basic Refrigeration Cycle
        A. Components/functions
          1. compressor
          2. condenser
          3. metering device
          4. evaporator
        B. Functions
          1. compressor
          2. condenser
          3. metering device
          4. evaporator
      II. Comfort
          A. Factors
            1. temperature
            2. humidity
            3. air movement
            4. air cleanliness
          B. Food energy to body energy
            1. metabolism
            2. men
            3. women
            4. elderly
          C. Body temperature
            1. conduction
            2. convection
            3. evaporation
            4. radiation
          D. Comfort chart
            1. temperature-humidity relationship
            2. type of clothing
        III. Psychometric Charts Terms/Points/Applications and Conditions for Standard Air
            A. Terms
              1. dry bulb (DB)
              2. wet bulb (WB)
              3. dew point (DP)
              4. relative humidity (RH)
              5. specific humidity (grains of water per lb. of air) (GR)
              6. enthalpy (L) (BTU/lb.)
              7. sensible heat ratio (SHR)
              8. total heat
            B. Points
              1. dry bulb line(s)
              2. wet bulb line (s)
              3. dew point line(s)
              4. relative humidity lines
              5. specific humidity scale
              6. enthalpy scale
              7. sensible heat scale
            C. Application
              1. Room conditions
              2. Sensible heat ratio line (SHRL)
              3. Leaving conditions
              4. Apparatus dew point
              5. Sensible heat process
                a. heating
                b. cooling
              6. Humidifying
              7. Dehumidifying
              8. Cooling and dehumidifying
              9. Heating and humidifying
              10. Cooling and humidifying
              11. Chemical dehumidifying
            D. Conditions for standard air
              1. 14.7 psi
              2. 69o F
              3. 13.34 ft3/lb
              4. .075 lb/ft3
              5. .24 BTU/lb
          IV. Cooling Load
              A. Solar
              B. Conduction
                1. walls
                2. windows
                3. doors
                4. roof
                5. floor
              C. Infiltrators
              D. Radiation
            V. Types/Styles of Cooling Equipment
                A. Evaporative coolers
                B. Packaged equipment
                C. Split equipment
                D. "A" coil
                E. Slant coil
                F. H coil
                G. Side-air-discharge
                H. Top-air-discharge
                I. Other
              VI. Compressor Types
                  A. Reciprocating
                  B. Rotory
                  C. Scroll
                  D. Other
                VII. Fixed Bore/Thermostatic Metering Devices
                    A. Fixed bore
                      1. operation
                      2. capillary tube
                      3. orifice
                    B. Thermostatic
                      1. operation
                      2. internally equalized
                      3. externally equalized
                      4. types of charges
                      5. bulb mounting position
                        a. vertical pipe
                        b. horizontal pipe
                  VIII. Forced-Air Systems
                      A. Purposes
                      B. Components
                        1. blower (fan)
                          a. propeller
                          b. forward curved centrifugal fan (squirrel cage)
                        2. air supply system (supply duct)
                        3. return air system (return duct)
                        4. grill
                        5. registers
                    IX. Duct Pressures, Unit of Measure and Air Testing Equipment
                        A. Pressure
                          1. total
                          2. static
                          3. velocity
                        B. Unit of measure
                        C. Measuring (testing) equipment
                          1. inclined manometer
                          2. velometer
                          3. magnehelic
                          4. other
                      X. Types of Duct Systems
                          A. Plenum
                          B. External plenum
                          C. Reduced plenum
                          D. Perimeter loop
                          E. Other
                        XI. Duct Material/Configurations
                            A. Duct material
                              1. Sheet steel
                              2. Fiberglass
                              3. Flexible
                            B. Configurations
                              4. Square (rectangular)
                              5. Round
                              6. Oval
                          XII. Methods of Supplying Air and Duct Velocities
                              A. Heating only
                                1. office buildings
                                2. residential
                                3. velocity
                                  a. main trunk
                                  b. branch
                                  c. supply diffuser
                                  d. return grill
                              B. Cooling only
                                1. office buildings
                                2. residential
                                3. velocity
                                  a. main trunk
                                  b. branch
                                  c. supply diffuser
                                  d. return grill
                              C. Heating-cooling
                                1. office buildings
                                2. residential
                                3. velocity
                                  a. main trunk
                                  b. branch
                                  c. supply diffuser
                                  d. return grill
                            XIII. Safety Control and Operation
                                A. Thermostat
                                  1. low voltage
                                  2. line voltage
                                B. Relays
                                  1. coil voltage (s)
                                  2. voltage contact (s) switch
                                  3. current rating
                                C. Contactors
                                  1. coil voltage (s)
                                  2. current rating
                                D. Pressure switches
                                  1. high pressure
                                    a. auto reset
                                    b. manual reset
                                    c. non-adjustable
                                  2. low pressure
                                    a. auto reset
                                    b. manual reset
                                    c. non-adjustable
                                    d. loss of refrigerant
                                E. Overloads
                                  1. heat active
                                  2. current active
                                  3. heat and/or current active
                                  4. two wire
                                  5. 3 wire
                                  6. internal
                                  7. external
                                F. Time delay relay (short cycle relay)
                                G. Other
                              XIV. Starting Components (PSC motors)
                                  A. Running capacitor
                                  B. Hard start kit
                                    1. starting capacitor
                                    2. potential relay
                                XV. Operating Conditions Versus Design Conditions
                                    A. Load added by humidity
                                    B. Outside ambient below design conditions
                                    C. Outisde ambient above design conditions
                                    D. High efficiency - all conditions
                                    E. Manufacturer's charts
                                      1. superheat
                                      2. charging
                                    F. Voltage at unit to unit rated voltage
                                  XVI. Heat Pump Operation Versus Air Conditioner
                                      A. 4-way valve
                                      B. Accumulator
                                      C. Check valves
                                      D. Indoor coil
                                      E. Outdoor coil
                                      F. Defrost cycle
                                      G. Refrigerant flow for heating and cooling
                                      H. Comparison - air conditioner
                                    XVII. Heat Pumps
                                        A. Types
                                          1. air to air
                                          2. water to air
                                          3. ground to air
                                          4. air to water
                                          5. water to water
                                        B. First term - heat source
                                        C. Second term - heat rejection medium
                                      XVIII. Metering Devices
                                          A. Capillary tube
                                          B. Thermostatic expansion valve
                                          C. Electronic expansion valve
                                          D. Orifice type
                                          E. Other
                                        XIX. Terms and Performance Relationship
                                            A. Coefficient of performance (COP)
                                            B. Balance point
                                              1. system capacity
                                              2. building heating load
                                            C. Auxiliary heat
                                              1. defrost
                                              2. compensate for equipment deficiency
                                            D. Ambient temperature to heat capacity
                                          XX. Heat Pump Controls
                                              A. Low voltage thermostats
                                                1. single stage
                                                2. multi-stage
                                              B. Relays
                                                1. change over
                                                2. defrost
                                                3. fan
                                                4. compressor
                                              C. Heating controls
                                                1. outdoor thermostat
                                                2. thermostatic overloads
                                              D. Defrost timers
                                              E. Defrost termination thermostats
                                              F. Other
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