Source: https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/mechanism/

instrument mechanism / verified-clean

# Moist Air Enthalpy Calculator mechanism

The inspectable method record for Moist Air Enthalpy Calculator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The formula can pass for explicitly supplied T in degrees Celsius and W in kg/kg dry air. The catalog entry is not complete because it also advertises RH as an input without specifying pressure, saturation-pressure calculation, or conversion behavior. The empty honest_label should be replaced with wording such as: approximate moist-air enthalpy per kg dry air; T in degrees Celsius; W in kg/kg dry air; RH input requires pressure and a psychrometric model.

- The formula h=1.006T+W(2501+1.86T) is the standard approximate moist-air enthalpy formula when T is dry-bulb temperature in degrees Celsius and W is humidity ratio in kg water vapor per kg dry air.

- The input declaration says W or RH, but no relative-humidity conversion formula is provided. Converting RH to W requires total pressure and a saturation-vapor-pressure model, so RH alone is insufficient.

## Units and conventions

- T must be in degrees Celsius, not kelvin or degrees Fahrenheit.

- W must be a dimensionless mass ratio in kg water vapor/kg dry air; it must not be entered as percent or directly as g/kg without conversion.

- The output h is in kJ/kg dry air.

- The empirical constants imply the usual psychrometric reference state and approximation; the reference convention should be documented if high accuracy is claimed.

- If RH is accepted, total barometric pressure and the saturation-vapor-pressure correlation must also be specified.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "T_C": 25,
    "W_kg_per_kg_dry_air": 0.01
  },
  "expected_outputs": {
    "h_kJ_per_kg_dry_air": 50.625
  },
  "working": "h=1.006(25)+0.010[2501+1.86(25)]\n=25.150+0.010[2501+46.500]\n=25.150+0.010(2547.500)\n=25.150+25.475\n=50.625 kJ/kg dry air"
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

An extreme but representable JavaScript input causes the enthalpy multiplication to overflow to Infinity. The calculator should reject or explicitly flag this result rather than treating it as a valid physical enthalpy. A separate unit-convention ambiguity also permits materially different physical interpretations.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`