{
  "schemaVersion": 1,
  "slug": "air-purifier-room-size-calculator",
  "category": "household",
  "kind": "implementation",
  "independentValidation": false,
  "implementationHash": "d52805ab9778e8de67c0dca14d7268a43098356996e6dd659aaf9bd1dee7a993",
  "provenance": "Generated from the calculation contract used by the published page. Publication is not external validation.",
  "sourceFiles": [
    "data/calculators/air-purifier-room-size-calculator.json",
    "src/engine.js"
  ],
  "runtimeSource": "/sources/engine.txt",
  "runtimeHash": "5c888d8898afbdee36267bb9977829e1e2ac568f6677c8ee87469c139864645c",
  "scope": "The compute function records implemented equations, constants, lookup tables and custom rules. Inputs record defaults and allowed values; outputs record precision and units. Defaults are examples, not recommendations. General background references are not evidence for this specific algorithm.",
  "publishedFormula": {
    "formula": "CADR = L × W × H × ACH ÷ 60",
    "vars": [
      [
        "CADR",
        "required CADR (ft³/min)"
      ],
      [
        "L",
        "room length (ft)"
      ],
      [
        "W",
        "room width (ft)"
      ],
      [
        "H",
        "ceiling height (ft)"
      ],
      [
        "ACH",
        "air changes per hour"
      ]
    ],
    "note": "ACH presets: 3 basic, 4.8 standard, 6 allergy, 8 smoke; multiply CADR by 1.699 for m³/h."
  },
  "externalEvidence": null,
  "contract": {
    "compute": "const A = { basic:3, standard:4.8, allergy:6, smoke:8 }; const a = A[ach] || 4.8; const area = length*width; const volume = area*ceilingHeight; const cadr = volume*a/60; return { area, volume, cadr, cadrMetric: cadr*1.699, maxRoomFor300: 300/(ceilingHeight*a/60) };",
    "inputs": [
      {
        "name": "length",
        "type": "number",
        "default": 15,
        "min": 0,
        "max": 200,
        "step": 0.5,
        "slider": true
      },
      {
        "name": "width",
        "type": "number",
        "default": 12,
        "min": 0,
        "max": 200,
        "step": 0.5,
        "slider": true
      },
      {
        "name": "ceilingHeight",
        "type": "number",
        "default": 8,
        "min": 6,
        "max": 30,
        "step": 0.5,
        "slider": true
      },
      {
        "name": "ach",
        "type": "select",
        "default": "standard",
        "options": [
          {
            "value": "basic"
          },
          {
            "value": "standard"
          },
          {
            "value": "allergy"
          },
          {
            "value": "smoke"
          }
        ]
      }
    ],
    "outputs": [
      {
        "name": "cadr",
        "precision": 0,
        "unit": "CFM"
      },
      {
        "name": "area",
        "precision": 1,
        "unit": "sq ft"
      },
      {
        "name": "volume",
        "precision": 0,
        "unit": "cu ft"
      },
      {
        "name": "cadrMetric",
        "precision": 0,
        "unit": "m³/h"
      },
      {
        "name": "maxRoomFor300",
        "precision": 0,
        "unit": "sq ft"
      }
    ],
    "interpret": null
  }
}