mirror of
https://github.com/Hestia-Homes/Model.git
synced 2026-06-08 11:17:27 +00:00
068088bc2f
Two compounding bugs were over-counting the SAP 10.2 §4 (56)m cylinder
storage loss by ~76 kWh/yr across all 17 cylinder-with-immersion
corpus variants (cascade HW kWh 2460.40 vs worksheet 2384.12):
(1) **Extractor gap.** Elmhurst Summary §15.1 "Hot Water Cylinder"
block lodges `Cylinder Size` / `Insulation Thickness` but NOT
`Cylinder Thermostat`. The thermostat is lodged separately in
§16 "Recommendations" as `Cylinder thermostat (Already installed)`.
The extractor only searched §15.1, so `cylinder_thermostat`
resolved to None for every variant on property 001431. The
cascade then defaulted `has_cylinder_thermostat=False`, applying
SAP 10.2 Table 2b's ×1.3 "no thermostat" multiplier.
(2) **Cascade spec gap.** `_separately_timed_dhw` returned True for
any cylinder-lodged cert regardless of HW fuel. Per SAP 10.2
Table 2b note b) (PDF p.159):
> "Multiply Temperature Factor by 0.9 if there is separate time
> control of domestic hot water (boiler systems, warm air systems
> and heat pump systems)"
Electric immersion is NOT in the bracketed list — the ×0.9
reduction is restricted to boiler / warm-air / HP systems. Pre-
slice the cascade over-applied ×0.9 on electric-immersion certs.
Combined, the cascade computed TF = 0.60 × 1.3 × 0.9 = 0.702 vs the
worksheet's TF = 0.60 (base — thermostat present, immersion exempt).
After both fixes the cascade HW kWh matches the worksheet's (64) at
1e-3 precision (2384.116 vs 2384.12).
Corpus impact (16 cylinder-with-immersion variants on 18-hour meter):
| variant | SAP_c shift | Cost shift |
|--------------|------------:|-----------:|
| electric 1 | -0.20 → -0.06 | -£3.34 |
| electric 2 | -1.27 → +0.47 | -£4.44 |
| electric 3 | +2.42 → +2.55 | -£2.91 |
| electric 5 | -0.06 → +0.07 | -£3.06 |
| electric 6 | +1.19 → +1.33 | -£3.20 |
| electric 7 | +1.14 → +1.29 | -£3.35 |
| electric 8 | -0.41 → -0.26 | -£3.50 |
| electric 9 | -0.24 → -0.12 | -£2.91 |
| solid fuel 4-11 | -0.45..-0.09 → -0.29..+0.10 | -£3 to -£4 |
The HW kWh line closes cleanly; some SAP residuals sign-flip slightly
because the cascade's now-correct HW kWh exposes the SH+Sec demand
mismatch for storage heaters (electric 3/6/7 — open driver is the
Table 11 `main_heating_category=None` default for codes 401/402,
queued for a mapper-side slice).
Tests:
- new AAA test `test_separately_timed_dhw_excludes_electric_immersion_per_table_2b_note_b`
- 16 corpus pins re-tightened (8 electric + 8 solid fuel)
Extended handover suite: 883 pass (was 882; +1 new test), 0 fail.
Pyright net-zero on touched files (43 → 43 errors, all pre-existing).
Per [[feedback-spec-citation-in-commits]] +
[[feedback-spec-floor-skepticism]] (the "HW +76 kWh uniform overcount"
across 17 variants traced to TWO spec-citable defaults the cascade
was getting wrong, not a precision floor).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
|
||
|---|---|---|
| .. | ||
| fixtures | ||
| __init__.py | ||
| test_elmhurst_end_to_end.py | ||
| test_elmhurst_extractor.py | ||
| test_end_to_end.py | ||
| test_extractor.py | ||
| test_heating_systems_corpus.py | ||
| test_pdf.py | ||
| test_summary_pdf_mapper_chain.py | ||