Slice S0380.99: PCDB Table 329 (MV In-Use Factors) ETL + parser + lookup (PCDF Spec §A.20)

PCDF Spec Rev 6b §A.20 (May 2021) Format 430 — Mechanical Ventilation
In-Use Factors Table. Pcdb10.dat carries Format 432 (header
`$329,432,4,2021,11,25,2`), an extended-field version where Format
430 fields 1-4 (system_type + 3 SFP factors for the "no approved
scheme" variant) align at positions 0..3. The remainder of Format
432 carries MVHR adjustments + "with approved scheme" variants +
additional Format 432 columns, preserved verbatim in `raw` for
follow-up slices.

Per PCDF Spec §A.20 field 1 — system types:
  1  = centralised MEV
  2  = decentralised MEV
  3  = balanced whole-house MV (with or without heat recovery)
  5  = positive input ventilation (PIV)
  10 = default data (used with SAP Table 4g defaults)

Decentralised MEV (system_type=2) IUFs:
  SFP × ducting type:
    flexible:   1.45 (field 2)
    rigid:      1.30 (field 3)
    no-duct:    1.15 (field 4 — through-wall fans)

Per spec Note: "If there is no applicable approved installation
scheme the values for with and without scheme are the same." Cert
000565 lodges "Approved Installation: No" → use the "no scheme"
IUFs.

Validation for cert 000565 against worksheet line (230a):
  Σ(SFP_j × FR_j × IUF_j) for the 4 lodged fans:
    in-room kitchen:        1×0.15×13×1.45 = 2.8275
    in-room other wet:      1×0.15× 8×1.45 = 1.7400
    through-wall kitchen:   2×0.11×13×1.15 = 3.2890
    through-wall other wet: 3×0.14× 8×1.15 = 3.8640
  Σ = 11.7205 W (matches worksheet "total watage = 11.7205")
  Σ(FR_j) = 92.0 l/s (matches worksheet "total flow = 92.0000")
  SFPav = 11.7205 / 92.0 = 0.1274 W/(l/s) ✓ matches worksheet

Foundation only this slice — typed parser + ETL + runtime lookup
`mv_in_use_factors_record(system_type)`. No cascade integration; no
behavioural change on any cert. Next slice S0380.100 wires the
SFPav formula.

5 Table 329 records ingested. Pyright net-zero per touched file.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

domain/sap10_calculator/tables/pcdb/__init__.py

@@ -32,8 +32,10 @@ from domain.sap10_calculator.tables.pcdb.parser import (
     GasOilBoilerRecord,
     HeatPumpRecord,
     MevFanConfig,
+    MvInUseFactorsRecord,
     parse_decentralised_mev_row,
     parse_heat_pump_row_raw,
+    parse_mv_in_use_factors_row,
 )
 
 __all__ = [
@@ -41,9 +43,11 @@ __all__ = [
     "GasOilBoilerRecord",
     "HeatPumpRecord",
     "MevFanConfig",
+    "MvInUseFactorsRecord",
     "decentralised_mev_record",
     "gas_oil_boiler_record",
     "heat_pump_record",
+    "mv_in_use_factors_record",
 ]
 
 
@@ -54,6 +58,9 @@ _TABLE_105_JSONL: Final[Path] = (
 _TABLE_322_JSONL: Final[Path] = (
     _PCDB_DATA_DIR / "pcdb_table_322_decentralised_mev.jsonl"
 )
+_TABLE_329_JSONL: Final[Path] = (
+    _PCDB_DATA_DIR / "pcdb_table_329_mv_in_use_factors.jsonl"
+)
 _TABLE_362_JSONL: Final[Path] = (
     _PCDB_DATA_DIR / "pcdb_table_362_heat_pumps.jsonl"
 )
@@ -172,3 +179,36 @@ def decentralised_mev_record(pcdb_id: int) -> Optional[DecentralisedMevRecord]:
     for MEV centralised or decentralised) per the spec's first-tier
     cascade rule (§2.6.3 / Table 4g note 1)."""
     return _TABLE_322_BY_ID.get(pcdb_id)
+
+
+def _load_table_329() -> dict[int, MvInUseFactorsRecord]:
+    """Read the Table 329 NDJSON at import time and build a by-system-
+    type dict of typed `MvInUseFactorsRecord`s. Returns empty when the
+    jsonl is missing (ETL bootstrap concession; production callers
+    always observe the committed file)."""
+    records_by_type: dict[int, MvInUseFactorsRecord] = {}
+    if not _TABLE_329_JSONL.exists():
+        return records_by_type
+    with _TABLE_329_JSONL.open(encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if not line:
+                continue
+            data = json.loads(line)
+            raw_fields = tuple(data["raw"])
+            record = parse_mv_in_use_factors_row(",".join(raw_fields))
+            records_by_type[record.system_type] = record
+    return records_by_type
+
+
+_TABLE_329_BY_SYSTEM_TYPE: Final[dict[int, MvInUseFactorsRecord]] = _load_table_329()
+
+
+def mv_in_use_factors_record(system_type: int) -> Optional[MvInUseFactorsRecord]:
+    """Table 329 lookup by SAP 10.2 ventilation system type (1, 2, 3,
+    5, 10 per PCDF Spec §A.20). Returns None when the system_type is
+    not in Table 329 — caller can fall back to SAP 10.2 Table 4g
+    defaults (system_type=10) or skip the IUF adjustment per spec
+    Note: "If there is no applicable approved installation scheme the
+    values for with and without scheme are the same"."""
+    return _TABLE_329_BY_SYSTEM_TYPE.get(system_type)

domain/sap10_calculator/tables/pcdb/data/pcdb_table_329_mv_in_use_factors.jsonl

@@ -0,0 +1,5 @@
+{"system_type": 1, "raw": ["1", "1.7", "1.4", "", "", "", "", "", "1.6", "1.3", "", "", "", "", "", "", "", "", "", "", "", "", "2021/Nov/22 14:55"]}
+{"system_type": 2, "raw": ["2", "1.45", "1.3", "1.15", "", "", "", "", "1.45", "1.3", "1.15", "", "", "", "", "", "", "", "", "", "", "", "2021/Nov/22 14:55"]}
+{"system_type": 5, "raw": ["5", "1.7", "1.4", "", "", "", "", "", "1.6", "1.25", "", "", "", "", "", "1.1", "1.1", "", "", "", "", "", "2021/Nov/22 14:55"]}
+{"system_type": 3, "raw": ["3", "1.7", "1.4", "", "0.25", "0.5", "0.9", "0.8", "1.6", "1.25", "", "0.25", "0.5", "0.9", "0.8", "1.1", "1.1", "", "0.25", "0.5", "0.9", "0.8", "2021/Nov/22 14:55"]}
+{"system_type": 10, "raw": ["10", "2.5", "2.5", "2.5", "0.25", "0.25", "0.7", "0.7", "2.5", "2.5", "2.5", "0.25", "0.25", "0.7", "0.7", "2.5", "2.5", "2.5", "0.25", "0.25", "0.7", "0.7", "2021/Nov/22 14:55"]}

domain/sap10_calculator/tables/pcdb/etl.py

@@ -16,15 +16,18 @@ from pathlib import Path
 from domain.sap10_calculator.tables.pcdb.parser import (
     DecentralisedMevRecord,
     GasOilBoilerRecord,
+    MvInUseFactorsRecord,
     RawPcdbRecord,
     parse_table_105,
     parse_table_322,
+    parse_table_329,
     parse_table_raw,
 )
 
 
 _TABLE_105_OUTPUT_FILENAME: str = "pcdb_table_105_gas_oil_boilers.jsonl"
 _TABLE_322_OUTPUT_FILENAME: str = "pcdb_table_322_decentralised_mev.jsonl"
+_TABLE_329_OUTPUT_FILENAME: str = "pcdb_table_329_mv_in_use_factors.jsonl"
 # Tables ingested as `RawPcdbRecord` (pcdb_id + raw) — per-field typing is
 # deferred to follow-up slices when the cert-side wiring for each table
 # lands.
@@ -81,6 +84,17 @@ def run_etl(*, source: Path, output_dir: Path) -> None:
             for r in parse_table_322(dat_text)
         ],
     )
+    # Table 329 (MV In-Use Factors) — typed via `parse_table_329`,
+    # exposing the per-ducting-type SFP IUF multipliers for "no
+    # approved scheme" installations (the only variant our cohort
+    # exercises). Stored as raw row + typed-on-load.
+    _write_ndjson(
+        output_path=output_dir / _TABLE_329_OUTPUT_FILENAME,
+        records=[
+            _mv_in_use_factors_record_to_jsonable(r)
+            for r in parse_table_329(dat_text)
+        ],
+    )
     for table_id, filename in _RAW_TABLES.items():
         _write_ndjson(
             output_path=output_dir / filename,
@@ -98,6 +112,16 @@ def _decentralised_mev_record_to_jsonable(
     return {"pcdb_id": record.pcdb_id, "raw": list(record.raw)}
 
 
+def _mv_in_use_factors_record_to_jsonable(
+    record: MvInUseFactorsRecord,
+) -> dict[str, object]:
+    """Serialise a typed Table 329 record. Table 329 is keyed by
+    `system_type` rather than `pcdb_id`, so this dict uses `system_type`
+    as the primary identifier; lookup callers `mv_in_use_factors(
+    system_type)` resolve via the same key."""
+    return {"system_type": record.system_type, "raw": list(record.raw)}
+
+
 if __name__ == "__main__":  # pragma: no cover — manual ETL invocation
     data_dir = Path(__file__).resolve().parent / "data"
     run_etl(

domain/sap10_calculator/tables/pcdb/parser.py

@@ -519,6 +519,79 @@ def parse_table_322(dat_text: str) -> list[DecentralisedMevRecord]:
     return [parse_decentralised_mev_row(row) for row in _walk_table_records(dat_text, "322")]
 
 
+# Table 329 (MV In-Use Factors) — PCDF Spec Rev 6b §A.20 Format 430.
+# pcdb10.dat carries Format 432 (header `$329,432,4,2021,11,25,2`), an
+# extended-field version of spec Format 430. The spec's first 4 fields
+# (system_type + 3 SFP factors for "no approved scheme") align with the
+# Format 432 layout positions 0-3 — the only positions this slice
+# decodes. Trailing fields (MVHR adjustments + "with-scheme" variants +
+# additional Format 432 columns) are preserved verbatim in `raw` for
+# follow-up slices.
+#
+# System types per PCDF Spec §A.20 field 1:
+#   1  = centralised MEV
+#   2  = decentralised MEV
+#   3  = balanced whole-house MV (with or without heat recovery)
+#   5  = positive input ventilation (PIV)
+#   10 = default data (used when SFP / efficiency are taken from SAP
+#        Table 4g rather than the PCDB)
+_MV_IUF_IDX_SYSTEM_TYPE: Final[int] = 0
+_MV_IUF_IDX_SFP_FLEX_NO_SCHEME: Final[int] = 1
+_MV_IUF_IDX_SFP_RIGID_NO_SCHEME: Final[int] = 2
+_MV_IUF_IDX_SFP_NO_DUCT_NO_SCHEME: Final[int] = 3
+
+
+@dataclass(frozen=True)
+class MvInUseFactorsRecord:
+    """PCDB Table 329 (MV In-Use Factors) typed record.
+
+    SAP 10.2 §2.6 + §2.6.4 — in-use factors (IUF) are multiplied into
+    the PCDB SFP per equation (1) to allow for additional ductwork
+    losses encountered in practice. Per PCDF Spec §A.20 Note 1: "If
+    there is no applicable approved installation scheme the values
+    for with and without scheme are the same" — so this slice exposes
+    the "no scheme" SFP IUFs only; with-scheme variants are deferred
+    until a fixture lodges an approved installation.
+
+    Fields are Optional because each system_type populates a subset
+    (e.g. centralised MEV lodges the flex / rigid IUFs but no
+    through-wall — the no-duct field is blank).
+    """
+
+    system_type: int
+    sfp_iuf_flexible_no_scheme: Optional[float]
+    sfp_iuf_rigid_no_scheme: Optional[float]
+    sfp_iuf_no_duct_no_scheme: Optional[float]
+    raw: tuple[str, ...]
+
+
+def parse_table_329(dat_text: str) -> list[MvInUseFactorsRecord]:
+    """Walk a PCDB dat string, yielding parsed Table 329 (MV In-Use
+    Factors) records. One record per `system_type`; SFP IUFs decoded
+    for the "no scheme" variant per PCDF Spec §A.20 Note 1."""
+    return [parse_mv_in_use_factors_row(row) for row in _walk_table_records(dat_text, "329")]
+
+
+def parse_mv_in_use_factors_row(row: str) -> MvInUseFactorsRecord:
+    """Decode one Table 329 (MV In-Use Factors) Format-432 row into a
+    typed `MvInUseFactorsRecord`. Positions 0..3 align with PCDF Spec
+    Format 430 fields 1..4 — the "no approved scheme" SFP IUFs."""
+    fields = tuple(row.rstrip("\r\n").split(","))
+    return MvInUseFactorsRecord(
+        system_type=int(fields[_MV_IUF_IDX_SYSTEM_TYPE]),
+        sfp_iuf_flexible_no_scheme=_parse_optional_float(
+            fields[_MV_IUF_IDX_SFP_FLEX_NO_SCHEME]
+        ),
+        sfp_iuf_rigid_no_scheme=_parse_optional_float(
+            fields[_MV_IUF_IDX_SFP_RIGID_NO_SCHEME]
+        ),
+        sfp_iuf_no_duct_no_scheme=_parse_optional_float(
+            fields[_MV_IUF_IDX_SFP_NO_DUCT_NO_SCHEME]
+        ),
+        raw=fields,
+    )
+
+
 def parse_decentralised_mev_row(row: str) -> DecentralisedMevRecord:
     """Decode one Table 322 (Decentralised MEV) Format-428 row into a
     typed `DecentralisedMevRecord`.

domain/sap10_calculator/tests/test_pcdb_etl.py

@@ -310,6 +310,7 @@ def test_run_etl_writes_all_pcdb_table_jsonl_files(tmp_path: Path) -> None:
         "pcdb_table_143_micro_cogen.jsonl",
         "pcdb_table_313_flue_gas_heat_recovery.jsonl",
         "pcdb_table_322_decentralised_mev.jsonl",
+        "pcdb_table_329_mv_in_use_factors.jsonl",
         "pcdb_table_353_waste_water_heat_recovery.jsonl",
         "pcdb_table_362_heat_pumps.jsonl",
         "pcdb_table_391_high_heat_retention_storage_heaters.jsonl",

domain/sap10_calculator/tests/test_pcdb_table_329_lookup.py

@@ -0,0 +1,91 @@
+"""Tests for the runtime PCDB Table 329 (MV In-Use Factors) lookup.
+
+Table 329 maps each ventilation system_type (1=centralised MEV,
+2=decentralised MEV, 3=balanced w/wo HR, 5=PIV, 10=default) to a set
+of multiplicative in-use factors (IUF) that adjust the PCDB-lodged
+Specific Fan Power for the ducting type actually installed.
+
+The cascade applies the IUFs via SAP 10.2 §2.6.4 equation (1) — in
+the SFPav numerator the PCDB SFP for each fan is multiplied by the
+applicable in-use factor before the flow-weighted average is taken.
+
+Reference: BRE PCDB pcdb10.dat (header `$329,432,4,2021,11,25,2`);
+PCDF Spec Rev 6b §A.20 Format 430; SAP 10.2 specification §2.6 +
+§2.6.4.
+"""
+
+from __future__ import annotations
+
+from domain.sap10_calculator.tables.pcdb import mv_in_use_factors_record
+
+
+def test_mv_in_use_factors_for_decentralised_mev_returns_per_ducting_iufs() -> None:
+    """SAP 10.2 §2.6.4 — decentralised MEV (system_type=2) lodges
+    three per-ducting SFP in-use factors at PCDF Spec §A.20 fields
+    2, 3, 4 (Format 432 positions 1, 2, 3):
+
+        flexible ducting:   1.45
+        rigid ducting:      1.30
+        no ducting (TW):    1.15
+
+    The "no scheme" variants are exercised by cert 000565 (Approved
+    Installation: No); the with-scheme variants are deferred until a
+    cohort cert lodges an approved installation.
+
+    Cert 000565 validation:
+        ws line (230a) = IUF × SFPav × 1.22 × V → 127.5159 kWh
+        where SFPav = Σ(SFP_j × FR_j × IUF_j) / Σ(FR_j) = 11.7205 / 92 = 0.1274
+        and IUF_j ∈ {1.45 (in-room flex), 1.15 (through-wall)}
+    """
+    # Arrange / Act
+    record = mv_in_use_factors_record(2)
+
+    # Assert
+    assert record is not None
+    assert record.system_type == 2
+    assert record.sfp_iuf_flexible_no_scheme == 1.45
+    assert record.sfp_iuf_rigid_no_scheme == 1.30
+    assert record.sfp_iuf_no_duct_no_scheme == 1.15
+
+
+def test_mv_in_use_factors_for_centralised_mev_has_no_through_wall_iuf() -> None:
+    """Centralised MEV (system_type=1) doesn't include "through-the-
+    wall" / no-duct as a valid fan location — fans are centrally
+    located with ducting to each wet room. The PCDB record reflects
+    this by leaving field 4 (no-duct IUF) blank."""
+    # Arrange / Act
+    record = mv_in_use_factors_record(1)
+
+    # Assert
+    assert record is not None
+    assert record.system_type == 1
+    assert record.sfp_iuf_flexible_no_scheme == 1.7
+    assert record.sfp_iuf_rigid_no_scheme == 1.4
+    assert record.sfp_iuf_no_duct_no_scheme is None
+
+
+def test_mv_in_use_factors_for_default_data_system_type_10() -> None:
+    """System type 10 = default data per PCDF Spec §A.20: used when SFP
+    and efficiency are taken from SAP Table 4g rather than the PCDB.
+    All three SFP IUFs are 2.5 (per the pcdb10.dat record), reflecting
+    a conservative spread for un-lodged products."""
+    # Arrange / Act
+    record = mv_in_use_factors_record(10)
+
+    # Assert
+    assert record is not None
+    assert record.system_type == 10
+    assert record.sfp_iuf_flexible_no_scheme == 2.5
+    assert record.sfp_iuf_rigid_no_scheme == 2.5
+    assert record.sfp_iuf_no_duct_no_scheme == 2.5
+
+
+def test_mv_in_use_factors_returns_none_for_unknown_system_type() -> None:
+    """A system_type not in Table 329 returns None so callers can
+    fall back to default (system_type=10) or skip the IUF adjustment
+    entirely."""
+    # Arrange / Act
+    record = mv_in_use_factors_record(99)
+
+    # Assert
+    assert record is None