Khalim Conn-Kowlessar 39ae2cf0c2 fix(water-heating): split whc-903 immersion HW CO2/PE on off-peak tariffs ... SAP 10.2 Table 12d/12e: electric water heating on a 7-/10-hour tariff bills CO2/PE at the high-rate code (32/34) and low-rate code (31/33), kWh-weighted by the Table 13 high-rate fraction. The cost path already applied this split; the CO2/PE factors did not — they used the flat annual Table 12 figure (0.136 CO2 / 1.501 PE) for ALL dual-rate electric HW. That flat-annual behaviour (slice S0380.163) was validated only against HW-from-main "low-rate cost" certs (100% low, no high-rate split). It is NOT how Elmhurst bills a whc-903 ELECTRIC IMMERSION: the hand-built case-50 worksheet (000565 + dual immersion, 7-hour) splits HW CO2/PE into "high rate cost" (CO2 0.1475 / PE 1.5514) + "low rate cost" (CO2 0.1238 / PE 1.4429) weighted by the Table 13 fraction 0.1009. So flat-0.136 for immersion HW was a spec gap on our side, not an Elmhurst divergence. Fix: `_electric_immersion_hw_high_rate_fraction` threads the Table 13 fraction (scoped to whc-903, 7-/10-hour, cylinder data present) into the HW CO2 + PE factor helpers, which then blend the Table 12d/12e high/low codes. The flat rule is unchanged for HW-from-main and 18-/24-hour (no Table 12d split), so the S0380.163 41-variant cases and the existing pin are untouched. Case 50: rating CO2 2413.48 -> 2397.1237 = Elmhurst EXACT; demand CO2 2007.1384 EXACT; demand PE +111 -> +32.5 residual (within corpus PE noise). Corpus unchanged 73.3% / MAE 0.774 / CO2 0.08 / PE 3.4 (62 whc-903 off-peak certs; aggregate gauges hold). SAP unaffected (cost-based). Pin: test_whc903_immersion_hw_co2_pe_factors_split_high_low_on_off_peak; doc updated in SAP_CALCULATOR.md §8.1. pyright strict gate not run locally (pyright not installed in this container). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>		2026-06-24 09:05:21 +00:00
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__init__.py	refactor: lift-and-shift packages/domain/src/domain/sap → domain/sap10_calculator	2026-05-26 12:22:37 +00:00
cert_to_inputs.py	fix(water-heating): split whc-903 immersion HW CO2/PE on off-peak tariffs	2026-06-24 09:05:21 +00:00