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Step 1: establish comparable states
Use synchronized start and end readings, common pressure, consistent units and representative locations. Calculate each complete state from an independent input pair. Preserve uncertainty and do not substitute calculated properties for a second measurement.
Plotting helps reveal direction, but the table is the evidence record.
02
Step 2: classify delta T and delta W
Positive delta T with near-zero delta W is sensible heating; negative delta T with near-zero W is sensible cooling above dew point. Positive delta W indicates moisture addition; negative delta W indicates removal. Combined changes occupy diagonal directions.
Use a tolerance based on measurement uncertainty rather than demanding mathematical zero from field sensors.
03
Step 3: inspect saturation and enthalpy
A cooling path that crosses dew point requires condensation in the ideal model. Enthalpy difference adds the combined energy direction, but its use in rates requires dry-air mass flow.
From 30 °C/50% RH to saturated 12 °C, the verified model removes 4.581 g/kg water and 30.112 kJ/kg dry air. Those are per-mass differences, not condensate or capacity rates.
04
Step 4: compare plausible mechanisms
A horizontal right path can be heater or fan heat. A down-left path with lower W can be a wet cooling coil. A measured point between two inlets can be mixing. Leakage, duct gain, desiccant heat and spray processes can produce similar directions.
Choose the mechanism only after checking commands, flows, equipment boundaries and repeatability.
05
Limits and next action
The workbench represents ideal equilibrium states and selected balances, not transient control or equipment certification. A clean chart path is not proof of causation.
Next action: enter measured start and end states, export delta T, delta W and delta h, then write one observed conclusion and one separately labeled inference.