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

instrument / verified-clean

# Moist Air Enthalpy Calculator

The current ledger marks this instrument verified clean within the source-bound verification corpus.

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

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/moist-air-enthalpy-calculator/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Thermodynamics, Fluids & Aero

**Tranche**: tranche-4

**Evidence ID**: t4-072

**Ledger rows**: 1

No ledger note is attached.

## Review findings

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.

### Formula and scope findings

- 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.

### Unit assumptions

- 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.

## Boundary hardening

**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.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "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"
}
````

## Related workflows

[Weather StationHVAC energy](<https://guthlabs.ai/docs/instrument-workflows/weather-station/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

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

- `BOUNDARY_HAZARD_CATALOG.json`