Source: https://guthlabs.ai/docs/instruments/hvac-sensible-latent-load-calculator/implementation/

instrument implementation / implementation-contract

# HVAC Sensible/Latent Load Calculator implementation

A source-bound implementation contract for HVAC Sensible/Latent Load Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t4-084

**Effect**: Computation or source lookup only

## Input and validation requirements

The calculator has an unavoidable undefined-result trap when total load is zero: SHR becomes 0/0 or a nonzero value divided by zero. The specification also leaves the CFM-versus-mass-flow branch selection, humidity-ratio units, and load sign convention insufficiently defined, allowing materially different outputs or sign reversals.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "system": "metric",
    "mass_flow_kg_per_s": 0.5,
    "entering_temperature_C": 30,
    "leaving_temperature_C": 20,
    "entering_humidity_ratio_kg_per_kg_dry_air": 0.018,
    "leaving_humidity_ratio_kg_per_kg_dry_air": 0.01,
    "hfg_kJ_per_kg": 2500
  },
  "expected_outputs": {
    "Qs_kW": 5.03,
    "Ql_kW": 10,
    "Qt_kW": 15.03,
    "SHR": 0.33466467
  },
  "working": "ΔT=30−20=10 K. ΔW=0.018−0.010=0.008 kg/kg. Qs=1.006×0.5×10=5.03 kW. Ql=0.5×2500×0.008=10.00 kW. Qt=5.03+10.00=15.03 kW. SHR=5.03/15.03=0.33466467."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/hvac-sensible-latent-load-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/hvac-sensible-latent-load-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/hvac-sensible-latent-load-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`