{
  "version": 2,
  "layoutDir": 0,
  "conditions": {"altitude_ft": 0, "temperature_f": 70},
  "safetyFactorPercent": 15,
  "reportMetadata": {
    "projectName": "Example: two-path office supply",
    "systemName": "SF-1 branched supply, two terminals",
    "revision": "Example 2",
    "preparedBy": "",
    "checkedBy": "",
    "notes": "Illustrative geometry, not a validated design or manufacturer selection. 900 CFM through a 14 in round main trunk that splits at a 90 deg tee to two 12 in round runouts, each with one smooth 90 degree elbow (R/D 1.5) and an assumed 0.10 in. w.g. terminal drop. Exercises a branched (two critical-path) system. No fan sound data supplied. Check all assumptions before use."
  },
  "customFittings": [],
  "tree": {
    "id": "c1", "type": "fan",
    "props": {"name": "SF-1 Office supply fan", "cfm": 900, "fanType": "supply", "staticPressure_inWG": 0, "outletDuctType": "round", "outletDiameter_in": 14, "inletDuctType": "round", "inletDiameter_in": 14, "soundSource": "none"},
    "children": [{
      "id": "c2", "type": "duct",
      "props": {"name": "Main trunk - 15 ft", "length_ft": 15, "material": "galv_spiral", "ductType": "round", "diameter_in": 14, "width_in": 14, "height_in": 14, "pressureClass": "low", "fittings": [], "internallyLined": false},
      "children": [{
        "id": "c3", "type": "tee",
        "props": {"name": "Supply tee split", "Co_main": 0.10, "Co_branch": 0.62, "branchType": "boot45", "fittingId_main": "main_div", "fittingId_branch": "branch_div_90_boot45", "_drawer": "tee_boot45", "mainStubCFM": 450, "branchCFM": 450, "branchDirection": "cw", "ductType": "round", "diameter_in": 12, "width_in": 14, "height_in": 14},
        "children": [
          {
            "id": "c4", "type": "transition",
            "props": {"name": "Reducer 14 to 12", "Co": 0.20, "fittingId": "trans_gradual", "_drawer": "transition_gradual", "outletWidth": null, "ductType": "round", "diameter_in": 14, "width_in": 14, "height_in": 14},
            "children": [{
            "id": "c5", "type": "duct",
            "props": {"name": "Runout A - 8 ft", "length_ft": 8, "material": "galv_spiral", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12, "pressureClass": "low", "fittings": [], "internallyLined": false},
            "children": [{
              "id": "c6", "type": "elbow90",
              "props": {"name": "Turn A - 90 deg R/D 1.5", "Co": 0.22, "fittingId": "elbow_smooth_90_1_5d", "_drawer": "elbow90_1_5d", "turnDirection": "cw", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12},
              "children": [{
                "id": "c7", "type": "duct",
                "props": {"name": "Diffuser A approach - 6 ft", "length_ft": 6, "material": "galv_spiral", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12, "pressureClass": "low", "fittings": [], "internallyLined": false},
                "children": [{
                  "id": "c8", "type": "diffuser",
                  "props": {"name": "SD-1 Diffuser A", "cfm": 450, "airflowType": "supply", "publishedDrop_inWG": 0.1, "hasPublishedDrop": true, "fittingId": "us_supply_diffuser", "neckShape": "round", "neckDia": 12, "ncTarget": 35, "selfNoiseMode": "estimate"},
                  "children": []
                }]
              }]
            }]
            }]
          },
          {
            "id": "c9", "type": "duct",
            "props": {"name": "Branch runout - 10 ft", "length_ft": 10, "material": "galv_spiral", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12, "pressureClass": "low", "fittings": [], "internallyLined": false},
            "children": [{
              "id": "c10", "type": "elbow90",
              "props": {"name": "Turn B - 90 deg R/D 1.5", "Co": 0.22, "fittingId": "elbow_smooth_90_1_5d", "_drawer": "elbow90_1_5d", "turnDirection": "cw", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12},
              "children": [{
                "id": "c11", "type": "duct",
                "props": {"name": "Diffuser B approach - 6 ft", "length_ft": 6, "material": "galv_spiral", "ductType": "round", "diameter_in": 12, "width_in": 12, "height_in": 12, "pressureClass": "low", "fittings": [], "internallyLined": false},
                "children": [{
                  "id": "c12", "type": "diffuser",
                  "props": {"name": "SD-2 Diffuser B", "cfm": 450, "airflowType": "supply", "publishedDrop_inWG": 0.1, "hasPublishedDrop": true, "fittingId": "us_supply_diffuser", "neckShape": "round", "neckDia": 12, "ncTarget": 35, "selfNoiseMode": "estimate"},
                  "children": []
                }]
              }]
            }]
          }
        ]
      }]
    }]
  }
}