Introduced Modular Concept in 1989

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Introduction

• Introduced Modular Concept in 1989
• Focus on HVAC/R Industry
• 10 certified Technicians

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Strategy
To supply hand-held instruments that the HVAC/R
field technician needs to do his job better,
faster and more easily.
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The Problem

• Tests are not being performed to properly tune
  A/C system
• High efficient systems depend on these tests so
  that the system can operate like its supposed to
  - efficiently.
• If not properly tested and tuned, a high
  efficiency system is in fact a low efficiency
  system.
• FP Story

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Efficient Techs

• Technicians Concern- No time to do tests
  properly.
• Not doing tests properly causes call-backs.
• Technicians concern should be Do it right the
  first time and do it efficiently.

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Efficient A/C Systems

• Proper testing is the first step in proper
  tuning.
• Proper testing and tuning increases the
  efficiency of A/C units.
• Saves energy for the world and money for the
  owner.
• End result Efficient systems with maximum
  capacity, happy customers and healthy world.

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Tests

• Target Evaporator Exit Temperature (TEET)
• Superheat
• Subcooling

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Equipment
Example of equipment needed

• Measurements Needed
• Dry Bulb Temp (DB)
• Wet Bulb Temp (WB)
• Line Pressure
• Line Temperature

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System Setup

• Check todays weather conditions. If outside air
  is below 65F. Return air should be above 70F.
• Visually inspect system
• Ducts, clean filters, correct install, etc.
• Turn on System
• Let stabilize 15 min. Use this time to setup
  tests.

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System Setup

• Setup for tests can be done either one at a time
  or all at once.
• 3 DB Temperatures
• 1 WB Temperature (If using a sock, place in water
  during initial set-up)
• 2 Line Pressures
• 2 Line Temperatures

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Target Evap Exit Temp

• AKA temperature drop, temperature split.
• Focuses on the DB temp exiting the evap.
• Indication of proper airflow.

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TEET-Setup
WB and DB on filter before evap

• Place DB Thermocouple in return plenum before
  evaporator
• Measure and Record Into Evap Return DB

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TEET

• Place WB Thermocouple in return plenum close to
  the evap.
• Measure and Record Into Evap Return WB
  Temperature

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TEET

• Place a DB Thermocouple in the supply plenum near
  the evaporator.
• Measure and record Out of Evap DB Temp

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TEET-Calculations
Target Evap Exit Temp Chart

• Use Into Evap Return WB and DB to find Target
  Evap Exit Temp

• Adjust airflow until the Actual Evap Exit Temp
  Target Evap Exit Temp. Actual should within 3
  degrees of Target.
• If Actual Target, low airflow
• If Actual Target, low capacity, possibly high AF

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Superheat

• Best way to properly charge a fixed orifice
  system
• No more rules of thumb for the Target Superheat
• Superheat can range from 5F to 40F

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Superheat

• Attach a pressure gauge to the suction line
  service valve. Measure and record suction line
  pressure.
• Attach a thermocouple to the suction line near
  the compressor. Measure and record suction line
  temperature.

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Actual Superheat

• Convert the suction line pressure to temperature
  using a P/T chart or P/T calculator.
• This value is the saturation temperature.
• Suction line temp
• saturation temp
• Actual Superheat

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Target Superheat

• Place a WB thermocouple in supply plenum near the
  inlet of the evaporator. Let stabilize. Measure
  and record Indoor evap return WB temperature.
• Place a thermocouple on the condenser in the
  shade for outdoor DB entering the condenser.
  Measure and record the Outdoor DB reading.

Out Drybulb on condenser
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Target Superheat

• Look up the Target Superheat using the Indoor WB
  and outdoor DB.
• Data comes from tests on 200,000 A/C units.
  Proctor Engineering.

Target Superheat chart
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Actual vs. Target

• Adjust refrigerant charge until Target Superheat
  Actual Superheat
• If Actual Target, add refrigerant
• If Actual Target, remove refrigerant
• Actual superheat should be within 3 degrees of
  Target Superheat.

HVAC Guide SH OUTPUT FORM
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Subcooling

• Best way to properly charge a TXV System.
• Use manufactures Target Subcooling whenever
  possible.

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Subcooling

• Attach a pressure gauge to the liquid line
  service valve. Measure and record liquid line
  pressure
• Attach a thermocouple to the liquid line service
  valve. Measure and record liquid line temperature

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Subcooling

• Convert the pressure recorded from the pressure
  gauge to temperature using a P/T chart or P/T
  Calculator.
• Saturation temp
• Liquid line temp
• Actual Subcooling
• This value is the saturation temperature.

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Subcooling

• Adjust refrigerant charge until Actual Subcooling
  Target Subcooling
• If Actual Target, remove refrigerant
• If Actual Target, add refrigerant
• Actual subcooling should be within 3 degrees of
  Target Subcooling.

HVAC Guide SC OUTPUT FORM
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Tips

• Do as much set-up as you can during stabilization
  period.
• Clean filters, check ducts, check system install
  before testing. These things can cause poor
  running systems.
• When performing tests keep system running in
  normal running conditions, i.e. close blower
  doors.

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Conclusion

• Proper testing will result in
• Saved time for technician
• Better running A/C systems
• Saved money for the owner