SAP 10.2 §4 line 7690 (full spec PDF p.136) defines the cylinder storage
loss cascade for any cert with a hot water cylinder lodged:
(54) = V × L × VF × TF (Table 2 absence-of-declared-loss branch)
(55) = (54) (no manufacturer's declared loss)
(56)m = (55) × n_m (per spec, n_m = days in month)
where
L = Table 2 (PDF p.158) Note 1 formula for the lodged insulation type
(factory-insulated cylinders: 0.005 + 0.55/(t+4.0); loose jacket:
0.005 + 1.76/(t+12.8))
VF = Table 2a (PDF p.158) Note 2 closed form (120/V)^(1/3)
TF = Table 2b (PDF p.159) base 0.60 for indirect / electric-immersion
cylinders, × 1.3 if no thermostat, × 0.9 if DHW separately timed
Prior, `water_heating_from_cert` hard-coded `solar_storage_monthly_kwh
= zero12` and `_water_heating_worksheet_and_gains` had no path to
populate it. The new `cylinder_storage_loss_monthly_kwh` helper in
`worksheet/water_heating.py` exposes Tables 2 / 2a / 2b as small typed
functions plus a composite; the cert-side orchestrator in
`rdsap/cert_to_inputs.py::_cylinder_storage_loss_override` resolves
the lodged cylinder fields and injects the override.
Code → litres mapping ground-truthed against worksheet (47) line refs
in /sap worksheets/Additional data with api/<cert>/dr87-*.pdf for the
7-cert ASHP cohort: code 3 → 160 L (Medium, 6 certs) and code 4 →
210 L (Large, cert 9418). Codes 2 / 5 / 6 (Normal / Inaccessible /
Exact) absent from the cohort and not yet mapped.
Cylinder insulation type code → "factory_insulated" mapping
(_CYLINDER_INSULATION_TYPE_FACTORY = 1) ground-truthed against all 7
ASHP cohort worksheets ("Foam" lodgement → SAP 10.2 Table 2 Note 2
"factory-insulated cylinder where the insulation is applied in the
course of manufacture irrespective of the insulation material used").
RdSAP §3 default table (PDF p.57) — "Hot water separately timed:
Post-1998 boiler: Yes" — applied to heat-pump main heating systems
(cat 4) per the cohort worksheet evidence.
Cert 0380 (Mitsubishi ASHP, 160 L factory 50 mm, thermostat + separately
timed) lands the spec formula at worksheet (56) Jan = 36.9530 kWh/month
(test pinned at 1e-4); HW kWh/yr 242.21 → 431.38, recovering ~189 kWh/yr
of cylinder loss the cascade was previously dropping.
Cohort regression: cert 0390-2954 (oil boiler + 160 L cylinder) tightens
PE residual -28.6783 → -27.5026 kWh/m² and CO2 residual -2.7640 →
-2.6570 t/yr — both move closer to the lodged values (improvement).
Re-pinned with a slice-102b note.
Closed boiler chain tests (001479, 0330, 9501) unaffected: those certs
lodge has_hot_water_cylinder=false so the override stays None and the
existing zero-storage-loss default fires.
Sibling migration to the sap10_calculator move — `domain.ml` now lives
at the root-level layout (`domain/sap10_ml/`) matching the pattern
already used by `domain.addresses`, `domain.tasks`, `domain.postcode`,
and `domain.sap10_calculator`.
Changes:
- `git mv packages/domain/src/domain/ml → domain/sap10_ml` (19 files;
history preserved).
- Subpackage rename: `domain.ml` → `domain.sap10_ml`. 32 references
rewritten across .py and .md files: 11 internal + 21 external
(datatypes/epc/domain/mapper.py, 14 files in domain/sap10_calculator,
2 backend tests, 2 ADRs, 1 README, 1 design doc).
- Path-string updates: `pytest.ini` testpath
`packages/domain/src/domain/ml/tests` → `domain/sap10_ml/tests` so
ML tests stay in the default auto-discovered sweep. `CONTEXT.md`
also updated.
`packages/domain/src/domain/` is now empty — the workspace `domain/`
tree has been fully migrated. Together with the `domain/__init__.py`
deletions from the sap10_calculator commit (29ac35cc), `domain` is
now a single root-level namespace package with subpackages
{addresses, sap10_calculator, sap10_ml, tasks} + the standalone
`postcode.py` module.
Verified:
- Focused sweep (backend mapper-chain + sap10_calculator worksheet
e2e + golden fixtures): 99 passed / 19 failed — identical baseline.
- Wider sweep (all sap10_calculator + sap10_ml): 1654 passed / 20
failed (same pre-existing failures).
- domain/sap10_ml/tests: 210/210 PASSED at new path.
- Pyright net-zero: heat_transmission.py 13, cert_to_inputs.py 35,
mapper.py 33, rdsap_uvalues.py 1 (all unchanged from baseline).
Note: `packages/domain/pyproject.toml` still declares
`packages = ["src/domain"]` for the hatchling wheel — that target
directory is now empty and the wheel build is effectively a no-op.
Retiring the workspace package or repointing the wheel is a follow-up.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-26 13:01:35 +00:00
Renamed from packages/domain/src/domain/ml/tests/_fixtures.py (Browse further)
