Wayne's Air Conditioner Analyzer™ updated 4-3-17

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Update steady state values every 10 minutes

ODT °F   Refrigerant / System SEER   ID Return Air °F (at coil)   ID Supply Air °F (at coil)   ID Coil SEER
    DB  WB   DB WB  
High Pressure Source   Discharge Line °F ┌─────┐ Vapor Line °F
═════╩═ ═════             Suction Line °F    ╔═══╩═ ════════════════
═══════════════              ═══ ══ ═╗║   ═══════════════
═══Condenser════                ║║─┐ ════Evaporator═══
══ ══                │║     ══ ══
═════ ═════                │╚═╝  ═════ ═════
═══ -14~700psig ═══ ┌──▬──┐  └─▬─┘ ═══ -14~500psig ═══
Manufacturer intended TXV subcooling
Filter/dryer upstream Metering device upstream ═══════════════ Compressor Accumulator ═══════════════
  Liquid Line °F    ___
══════════════════════╩═ ══════════════════ ═ or ═ʘ════════
  Metering device  
Evaporator Superheat Normal TXV superheat is 10 - 20°
Evaporator & Return TD Normal evaporator saturation temperature is 25 - 35° below return air DB for 13 seer & up
Condenser Subcooling Normal TXV subcooling for 13 seer & up is 4 - 17°
Condenser & Outdoor TD Normal condenser saturation temperature for 13 seer & up is 10 - 20° over OD temperature
Compression Ratio Normal compression ratio for 13 seer & up is to
Indoor Air Delta Temp. ID dry and wet bulb temperatures are needed to determine the target evaporator ΔT
Legend: Adjustable Parameters
٭   Normal parameters modified for temperature or humidity that is outside of typical conditions       Too low    Normal Too High
      if less than if within if greater than
  No remedy suggested. Parameters are in range     TXV superheat     -    
  Somewhat or a little out of range. Use caution
with systems that otherwise perform satisfactorily
    subcooling     4 - 17   21  
    Fixed Orifice subcooling     17   21  
  Remedy or repair action is recommended         13 seer & up  
  Pressure access port   Evaporator Temperature Difference = Evaporator − Return air
Δh   Delta Enthalpy (change in total heat content of air)   13 SEER & up     -    
ΔT   Delta Temperature (sensible heat change of the air)   12 SEER or less     -    
CTD   Condenser Temperature Difference (from outdoor air)           
CR   Compression Ratio   Condenser Temperature Difference = Condenser − Outdoor air
CSH   Compressor Superheat (entering compressor)       13 SEER & up     -    
CST   Condenser Saturation Temperature       11 and 12 SEER     -    
DST   Discharge Saturation Temperature       9 and 10 SEER     -    
DB   Dry Bulb temperature       8 SEER or less     -    
ETD   Evaporator Temperature Difference (from return air)                    
ESH Evaporator SuperHeat (at insulted vapor line) Compression ratio = (high + ambient) ÷ (low + ambient)
EST Evaporator Saturation Temperature   13 SEER & up     -    
FO Fixed Orifice   11 and 12 SEER     -    
ID Indoor   9 and 10 SEER     -    
OD Outdoor   8 SEER or less     -    
ODT Outdoor Temperature (entering condenser)  
RA Return Air temperature (entering evaporator) Tolerance for thermometer/pressure gauge calibration  
SA Supply Air temperature (leaving evaporator) Tolerance for fixed orifice target superheat temperature  
SC Subcooling Tolerance for target evaporator air delta temperature  
sCFM Standard Air Cubic Feet per Minute Tolerance for target or manufactures TXV subcooling  
SH Superheat Tolerance for nominal CFM calculated from Δh  
SHR Sensible Heat Ratio Allowed temperature drop for upstream filter/dryer  
TD Temperature Difference (of refrigerant and air) Allowed temp. drop for heat pump OD metering device  
TSA Target Supply Air (temperature from ΔT chart) Minimum temperature for a fully charged evaporator  
TXV Thermal expansion Valve Maximum refrigerant  temperature entering compressor  
WB Wet Bulb temperature Min. temp. difference between max. TXV SC and CTD  
  R-22 estimated percentage of condenser pressure drop %
  R-410a estimated percentage of condenser pressure drop %
  Maximum suction line temperature above vapor line 0  
Notes:   FALSE   (all temperatures Fahrenheit)
This analyzer incorporates a flexible range for evaporator and condenser temperature differences and system compression ratios. This enables it to analyze a wide range of indoor and outdoor conditions. It has the ability to diagnose over forty different issues including a combination of issues. It will provide a list of possible causes and/or remedies.
This analyzer can be customized to a manufacturers model lineup and/or specific system. Send inquires to "wayne"(no space)"pendergast" at the domain name "comcast" with a dot, then "net".
Minimal evaporator pressure drop is not considered in calculations.
Run system on high stage and long enough for liquid refrigerant to un-migrate from crankcase, vapor line, coils and accumulator.
Return air wet bulb temperature is essential for diagnosis, humidity greatly affects the indoor coil which affects the entire system.
Record traversed average temperature of moving air shaded from radiant heat, (sun, body, heat exchanger, heater coil etc.) Use clamp style probes for taking pipe temperatures.
Discharge line temperature should be 225°F or less, 6" from compressor, if higher, check the manufacturer’s maximum.
When liquid refrigerant is present, its saturation temperature dictates the pressure. This saturation temperature is affected by heat absorption or rejection (airflow), the compressors ability to pump, and the metering devices ability to allow or restrict flow.
When adding refrigerant, it's best to open the charging valve to a pressure at, or just above, the desired EST. Letting the low side of the system "see" a high tank pressure can extend the time it takes for the refrigerant to stabilize.
If a steady state condition is not achievable, an inverted trap may be missing from the top of the vapor line riser, liquid traps may be in the horizontal vapor line, non-condensables may be in the system, or an oversized (hunting) TXV may be the cause.
For A/C units, every 1º of added subcooling without raising condensing pressure, produces an average increase of .5% system efficiency. Increasing both subcooling and condensing pressure (more than necessary to feed the metering device) reduces efficiency. For heat pumps, use the manufacturers recommended subcooling value (correct charge in cooling assures correct charge in heating).
Compressor amperage depends on both the rate of refrigerant flow and the difference in pressure. Without a significant change in flow, the compressor amperage will follow the compression ratio, when the CR is high the amperage will be high and vice-versa.
Flowing bubbles in a liquid line sight glass while subcooling is measured indicates non-condensables, impure refrigerant, or calibration error. A single bubble is likely due to expansion in the sight glass.
Calculations assume a pure refrigerant but can indicate the presence of non-condensables or mixtures. 
Psychrometric calculations made using .075 ft³/lb density and the perfect gas relationship for dry and moist air. Ideal Gas Law: pV=nRT
This calculator is a useful tool for assisting a technician with diagnostics and repairs, but it is the technicians responsibility to verify the validity of the analysis made by this application.
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