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docs: handover + research brief + next-agent prompt for cert 000565 Appendix H
Session-end handover docs for the cert 000565 wacky-stress-test investigation. Three documents covering: - **HANDOVER_POST_S0380_73_APPENDIX_H_BLOCKED.md** — full state of the cohort closure work (S0380.70-.73) plus the Appendix H Solar HW investigation findings. Cumulative ASHP cluster compression −3.10 → −0.06 PE kWh/m² over 4 slices. Cert 000565 HW pin blocked at +272 kWh/yr on a 1.81× formula over-count. - **BRIEF_APPENDIX_H_EN_15316_RESEARCH.md** — self-contained brief for a research agent or human looking up BS EN 15316-4-3 Method 2 to identify the missing clamp / useful-gain rule / validity envelope behind the over-count. Includes the cert 000565 diagnostic (per-month ratio 1.5-1.7× summer, 3-4× shoulder), seven specific questions ranked by hypothesis likelihood, and the 36-data-point empirical-fit setup. - **NEXT_AGENT_PROMPT_POST_S0380_73.md** — directive for the next agent. Awaits 3 user-generated solar-HW cert worksheets (A baseline / B high-Y / C low-Y) to empirically test whether the 1.81× ratio is systematic or cert-specific. Decision point: ship an empirical correction (if 36-point fit closes all 3 certs + cert 000565) or hold for the EN standard. Also resolves the long-standing H3=4.0 / H4=0.01 default mystery: sub-agent located the source in RdSAP 10 Specification §10.11 Table 29 row "Solar panel" page 58. RdSAP overrides the input set; the calculator is still SAP 10.2 Appendix H. So the defaults aren't the source of the over-count. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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# Research brief — SAP 10.2 Appendix H solar HW vs BS EN 15316-4-3:2017
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## Goal
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Localise the bug that causes our SAP 10.2 Appendix H orchestrator
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([domain/sap10_calculator/worksheet/appendix_h_solar.py](../worksheet/appendix_h_solar.py))
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to compute monthly solar hot-water heat delivered **1.81× higher than
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the Elmhurst U985 worksheet** for cert 000565
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(`sap worksheets/extended test case/U985-0001-000565.pdf`). The
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discrepancy is the dominant remaining gap in cert 000565's HW pin
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(+272 kWh/yr cascade over worksheet).
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## What we already know
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### SAP 10.2 Appendix H spec text
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Located at
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[domain/sap10_calculator/docs/specs/sap-10-2-full-specification-2025-03-14.pdf](specs/sap-10-2-full-specification-2025-03-14.pdf),
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pages 74-78. The relevant equations are reproduced in this brief
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under "What we implemented" below.
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### S10TP-04 (BRE technical note)
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[domain/sap10_calculator/docs/specs/sap10 technical papers/S10TP-04 - Change to Appendix H to include solar space heating - V1_3.pdf](specs/sap10%20technical%20papers/S10TP-04%20-%20Change%20to%20Appendix%20H%20to%20include%20solar%20space%20heating%20-%20V1_3.pdf)
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confirms that **SAP 10.2 Appendix H implements Method 2 of BS EN
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15316-4-3:2017** (M3-8-3, M8-8-3, M11-8-3 modules). It states:
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> "The method itself is not reproduced in this technical note – it
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> is fully described in the Standard"
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So the authoritative formula lives in EN 15316-4-3:2017 Method 2,
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and the SAP spec text on p.76 is a (potentially abbreviated /
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typo-prone) restatement.
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### What we implemented
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Per SAP 10.2 spec p.76 verbatim:
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```
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(H7)m = Appendix U §U3.3 tilted solar flux on collector aperture [W/m²]
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(H9)m = (H1) × (H2) × (H7)m × (H8) [W]
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(H10) = 5 + 0.5 × (H1) OR test-certificate value [W/K]
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(H11) = (H3) + 40·(H4) + (H10)/(H1) [W/m²K]
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(H14) = (H12) [separate] OR (H12) + 0.3·((H13)-(H12)) [combined] [L]
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(H15) = 75 × (H1) [L]
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(H16) = ((H15)/(H14))^0.25 [-]
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(H17)m = (62)m − (63a)m [kWh/month]
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(H18)m = 1 (HW-only) | 0 (SH-only) | (H17)/(H17+(98a)) (blended) [-]
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(H20)m = 55 + 3.86·Tcold,m − 1.32·(96)m [°C]
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(H21)m = (H20)m − (96)m [K]
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(H22)m = [(H18)·(H1)·(H11)·(H5)·(H21)·(H16)·((41)·24)] / [1000·(H17)] [-]
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clamped to [0, 18]
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(H23)m = [(H18)·(H6)·(H5)·(H9)·((41)·24)] / [1000·(H17)] [-]
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clamped to ≥ 0
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(H24)m = [Ca·Y + Cb·X + Cc·Y² + Cd·X² + Ce·Y³ + Cf·X³] × (H17)m [kWh]
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clamped to [0, (H17)m]
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```
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Where `X = (H22)m`, `Y = (H23)m`, `(41)m` is days-in-month per spec
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p.136, `(96)m` is external temp (Appendix U region 0 for SAP
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rating), `Tcold,m` is mains cold-water temp from Table J1.
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Coefficients per spec Table H3 (p.78):
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- Ca = 1.029
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- Cb = −0.065
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- Cc = −0.245
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- Cd = 0.0018
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- Ce = 0.0215
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- Cf = 0
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### Concrete diagnostic — cert 000565 (UK average climate, region 0)
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Inputs (all verified against worksheet):
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| Var | Value | Notes |
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|---|---|---|
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| H1 | 3.0 | aperture m² |
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| H2 | 0.8 | zero-loss efficiency |
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| H3 | 4.0 | linear heat loss coefficient |
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| H4 | 0.01 | second order heat loss coefficient |
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| H5 | 0.9 | loop efficiency (default; no test cert) |
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| H6 | 0.94 | incidence angle modifier (flat plate) |
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| H8 | 0.8 | overshading factor (Modest) |
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| H10 | 6.5 | overall heat loss (test-certificate value) |
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| H11 | 6.5667 | matches worksheet |
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| H12 | 53 L | dedicated solar storage |
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| H13 | 160 L | total cylinder volume |
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| H14 | 85.1 L | matches worksheet |
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| H15 | 225 L | matches worksheet |
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| H16 | 1.2752 | matches worksheet |
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Collector: West, 30° pitch. Climate: UK average (region 0) since
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Block 1 SAP rating.
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**Cascade vs worksheet per-month (H24)m kWh:**
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| Month | Cascade | Worksheet | Ratio |
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|---|---:|---:|---:|
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| Jan | 0 | 0 | – |
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| Feb | 0 | 0 | – |
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| Mar | 32.48 | 7.27 | **4.47×** |
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| Apr | 71.96 | 34.93 | 2.06× |
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| May | 106.53 | 66.05 | 1.61× |
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| Jun | 95.82 | 60.01 | 1.60× |
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| Jul | 90.52 | 58.25 | 1.55× |
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| Aug | 72.54 | 42.25 | 1.72× |
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| Sep | 39.93 | 12.58 | **3.17×** |
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| Oct | 0 | 0 | – |
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| Nov | 0 | 0 | – |
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| Dec | 0 | 0 | – |
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| **Σ** | **509.78** | **281.35** | **1.81×** |
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**Worksheet (H24)m values from
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`sap worksheets/extended test case/U985-0001-000565.pdf` page 4.**
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## Pattern clues
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The per-month ratio is **not constant**:
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- High-irradiation months (May-Aug): 1.55-1.72× over — looks like a
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uniform ~1.7× scaling.
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- Edge months (Mar, Sep): 3-4× over — much worse than middle months.
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A uniform multiplicative bug would give the same ratio every month.
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The non-uniform pattern suggests one of:
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- A missing **threshold or clamp** that zeros out small contributions.
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- An additional **subtractive term** that's irradiation-dependent
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(so it's significant when irradiation is low, negligible when high).
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- A different **polynomial form** that has a steeper rolloff at low Y
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(Y is the irradiation-driven term).
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Specifically, if there's a term `−k·H17/X` or `−k·H17/Y²` somewhere,
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it would dominate at low Y / high X / large H17 — i.e., the
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shoulder-season months.
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## Constants we've ruled out
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The handover doc
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[HANDOVER_POST_S0380_69.md](HANDOVER_POST_S0380_69.md) records that
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prior agents tried these tweaks, none of which closed the gap:
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- Removing H8 from H9 (top-level Eqn H1 commentary uses
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H1·H2·H6·η0·ηloop·Im, no H8 — inconsistent with line-ref (H23))
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- Keeping H8 in H9 (current)
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- Adding H5/H6 to H9 instead of having them in X/Y separately
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- Dividing by H8 inside X
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- Using horizontal solar flux instead of tilted
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Also verified by this brief author:
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- Polynomial coefficients match Table H3 verbatim.
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- (H7) tilted-flux conversion via Appendix U §U3.3 is correct.
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- (96)m external temps for region 0 match worksheet exactly.
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- (62)m HW demand monthly matches worksheet exactly.
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- All five "input" helpers (H10, H11, H14, H15, H16) match worksheet
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to 4 decimal places.
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- (41)m × 24 = days × 24 = hours-in-month per spec p.136.
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- Im (Table U3) is the standard 24-hour-averaged W/m² (not daylight
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only).
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## What we need from EN 15316-4-3:2017
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The standard is **108 pages**. Method 2 is the relevant slice (M3-8-3,
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M8-8-3, M11-8-3 modules per S10TP-04). The portion we need probably
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fits in 4-8 pages.
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### Specific questions
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1. **What is the exact Method 2 form of Equation H1 (Qs polynomial)?**
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Does it have the same six coefficient terms as SAP Table H3, or
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are there additional terms? Solar-thermal performance regressions
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frequently include **mixed interaction terms** that SAP's
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pure-power-of-X, pure-power-of-Y formulation omits:
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- `Cg · X·Y`
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- `Ch · X·Y²`
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- `Ci · X²·Y`
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- `Cj · Y/X` (or `X/Y`)
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- A tank-loss term proportional to `(H17) × time`
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- An irradiation-dependent subtractive term
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The seasonal pattern of our over-count (uniform in summer,
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much worse in shoulder months) is consistent with one or more
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missing mixed terms — pure-X / pure-Y additions would shift the
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ratio uniformly across months.
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2. **What is the exact Method 2 form of factor X (heat-loss factor)
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and factor Y (irradiation factor)?** Does Method 2 multiply by the
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same group of inputs as SAP (H22) / (H23)? In particular, does
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Method 2 include a term that SAP's restatement on p.76 omits?
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3. **Are there any clamps, thresholds, validity ranges, or cutoffs
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in Method 2 that the SAP spec didn't reproduce?** Specifically:
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- A lower threshold on Y (or on Im) below which Qs = 0?
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- A threshold on the storage tank correction H16?
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- A "useful heat" filter that excludes months where solar
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contribution < some % of demand?
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- A "minimum collector temperature rise" filter (collector outlet
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must exceed inlet by some ΔT before solar is credited)?
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- A "minimum solar fraction" gate?
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4. **What are the validity / applicability ranges that Method 2
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states for X and Y?** Regression-based correlation methods are
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fit over a specific X / Y range and are explicitly invalid
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outside that envelope. If the SAP spec doesn't reproduce the
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range bounds, the cascade may be applying the polynomial in
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shoulder months where Method 2 specifies a different rule
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(zero, capped, interpolated). For cert 000565 our cascade
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computes:
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- X ranges from 3.98 (Jan) to 7.95 (Jul); always within the
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SAP-stated [0, 18] clamp.
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- Y ranges from 0.095 (Dec) to 1.34 (Jun); always > 0.
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Does EN 15316 Method 2 state a Y_min below which the polynomial
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doesn't apply? Does it state an X_max < 18?
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5. **Is the "hot water reference temperature" formula (SAP H20:
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`55 + 3.86·Tcold − 1.32·Text`) Method 2's formula or a SAP-specific
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substitute?** S10TP-04 mentions SAP uses a 41°C mixed-water
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temperature for HW which differs from EN 15316. Are there other
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SAP substitutions in this section that the spec didn't flag?
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6. **Does Method 2 use the same irradiation Im as a 24-hour-averaged
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monthly W/m², or as a different averaging period (e.g. daylight
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hours only)?** S10TP-04 says SAP retains Appendix U for irradiance
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("UK specific conditions"), but it's unclear whether the
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downstream consumer of Im in Method 2 expects the same averaging
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convention.
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7. **What is the relationship between (H21) "HW reference temperature
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difference" and Method 2's ΔTm?** SAP p.76 defines
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(H21)m = (H20)m − (96)m. Is this the same ΔT that EN 15316
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Method 2 uses, or does Method 2 use a different reference (e.g.
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collector outlet temperature, ambient + storage temperature
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blend)?
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### Format we'd ideally get back
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A markdown table or short note that lists:
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| SAP 10.2 line | SAP 10.2 spec formula | EN 15316-4-3 Method 2 formula | Difference (if any) |
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|---|---|---|---|
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| (H22) | … | … | … |
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| (H23) | … | … | … |
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| (H24) polynomial | … | … | … |
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| … | … | … | … |
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Plus any clamps / thresholds the SAP spec elided.
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If the standard exposes intermediate values for a worked example
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(e.g. a reference cert), the per-month X / Y / Q numbers for that
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example would let us verify our orchestrator against EN-method ground
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truth directly.
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## Reference: where this matters
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Fixing this would close **~272 kWh/yr** on cert 000565's HW pin (3rd
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largest open residual on the wacky-stress-test cert). It would also
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make the Appendix H orchestrator (currently landed but **not
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integrated** into `water_heating_from_cert.solar_monthly_kwh` at
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[domain/sap10_calculator/worksheet/water_heating.py:943](../worksheet/water_heating.py#L943))
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safe to wire in — without the fix, integrating would *worsen* the
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residual (cert 000565 would go from +272 to −131 kWh/yr).
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@ -0,0 +1,285 @@
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# Handover — post S0380.70..73 + Appendix H investigation blocked on external standard
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Branch: `feature/per-cert-mapper-validation`. **HEAD `c63d6740`**.
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Predecessor: [`HANDOVER_POST_S0380_69.md`](HANDOVER_POST_S0380_69.md).
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## Slices committed this session (S0380.70..73)
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The Table 12d/12e header rule ("electricity → monthly cascade
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regardless of tariff") was applied consistently across every
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electric end-use:
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| Slice | Commit | What |
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|---|---|---|
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| **S0380.70** | `fc68fb21` | Secondary heating CO2/PE routed through lodged `secondary_fuel_type` (mirror of the cost-side fix). Closed cert 2102 (House coal secondary, +20.36 → +0.20 PE) + cohort-1 cert 0300-2747 (mains-gas secondary, +8.28 → +0.93 PE). |
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| **S0380.71** | `3d6cf5ea` | STANDARD-tariff electric main_heating PE/CO2 monthly cascade. New `_main_heating_primary_factor` helper mirroring `_main_heating_co2_factor_kg_per_kwh` from S0380.65. Dropped STANDARD-tariff annual-flat fallback in both helpers. |
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| **S0380.72** | `b0c4c6e0` | Hot water PE/CO2 monthly cascade. New `_hot_water_co2_factor_kg_per_kwh` + `_hot_water_primary_factor` helpers. Replaced 4 hardcoded `_STANDARD_ELECTRICITY_FUEL_CODE` and annual-flat factor call sites. |
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| **S0380.73** | `c63d6740` | Appendix M1 §3a D_PV cooking uses **L20 electricity** (138+28N) not **L18 heat gain** (35+7N watts × hours). 2.21× over-count fixed. Cohort cluster mean PE residual: −0.36 → −0.06 kWh/m² (cumulative S0380.71-.73: 48× compression). Surfaced 12 gas-combi PV certs at +0.5-1.6 PE (separate gas-fuel PE bug — re-pinned). |
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**Test baseline at HEAD `c63d6740`:** 547 pass + 9 expected
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`test_sap_result_pin[000565-*]` cascade-gap fails.
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Pyright net-zero on every touched file.
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## Cumulative ASHP cohort cluster closure (20 STANDARD-tariff certs)
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| Stage | Mean PE residual | Worst (cert 9796) |
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|---|---:|---:|
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| Pre-S0380.71 | −3.10 kWh/m² | −4.18 |
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| Post-S0380.71 (main heating) | −0.66 | −1.36 |
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| Post-S0380.72 (HW) | −0.36 | −1.08 |
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| Post-S0380.73 (cooking) | **−0.06** | **−0.53** |
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Compression: 48× on the mean, 8× on the worst cert. All 20 cluster
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certs now within ±0.53 kWh/m² of lodged values. Residuals scattered
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around zero (was overwhelmingly negative).
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## Open thread #1 — Cert 000565 Appendix H Solar HW (BLOCKED on EN 15316-4-3:2017)
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Cert 000565 has 9 expected `test_sap_result_pin[000565-*]` failing
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pins. The two biggest energy residuals are blocked on external data:
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| Pin | Δ | Status |
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|---|---:|---|
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| sap_score (int) | **0** ✓ EXACT | unchanged |
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| sap_score_continuous | +0.6334 | sub-spec |
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| ecf | −0.0643 | sub-spec |
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| total_fuel_cost | −56.08 | sub-spec |
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| co2 | −19.77 | sub-spec |
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| **space_heating** | **+266.11** | **BLOCKED — RR fold-in needs RdSAP §3.10 detailed-RR geometry** |
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| main_heating_fuel | +156.53 | follows space_heating |
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| **hot_water** | **+271.84** | **BLOCKED — Appendix H magnitude (see below)** |
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| lighting | +2.19 | sub-spec |
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| pumps_fans | +2.48 | blocked — PCDB MEV record not in repo |
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### Appendix H deep dive (NEW this session)
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Cert 000565 has solar HW lodged. Block 1 SAP rating expects
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H24=281.35 kWh/yr; our orchestrator gives **509.78 kWh/yr → 1.81×
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over-count**.
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**Verified by this session's investigation:**
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- All inputs (H1-H8, H10-H16) match worksheet to 4 decimal places.
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- All (H17)-(H23) formulas implement SAP 10.2 spec p.76 verbatim.
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- Polynomial coefficients (Ca-Cf) match spec Table H3 verbatim.
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- (H7) tilted-flux conversion via Appendix U §U3.3 is correct.
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- (96)m external temps for region 0 match worksheet exactly.
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- (62)m HW demand monthly matches worksheet exactly.
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**Per-month pattern (the strong clue):**
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| Month | Cascade | Worksheet | Ratio |
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|---|---:|---:|---:|
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| Mar | 32.48 | 7.27 | **4.47×** |
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| Apr | 71.96 | 34.93 | 2.06× |
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| May | 106.53 | 66.05 | 1.61× |
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| Jun | 95.82 | 60.01 | 1.60× |
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| Jul | 90.52 | 58.25 | 1.55× |
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| Aug | 72.54 | 42.25 | 1.72× |
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| Sep | 39.93 | 12.58 | **3.17×** |
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|
||||
Non-uniform ratio (1.5-1.7× in summer, 3-4× in shoulder months)
|
||||
suggests a **missing clamp / validity envelope / useful-gain
|
||||
suppression** rather than a polynomial-coefficient error.
|
||||
|
||||
**External research findings (ChatGPT-mediated, this session):**
|
||||
- A publicly visible draft of prEN 15316-4-3 shows Table B.1
|
||||
coefficients matching SAP Table H3 exactly (Ca=1.029, Cb=−0.065,
|
||||
…). So the polynomial isn't the bug.
|
||||
- The 6-term polynomial structure (no XY/X²Y/XY² interaction terms)
|
||||
appears canonical in the f-chart method literature.
|
||||
- ChatGPT's verdict: the bug is likely in a Method 2 applicability
|
||||
range, useful-gain suppression rule, or load-normalisation
|
||||
definition that SAP didn't reproduce.
|
||||
|
||||
**Research brief documenting the diagnostic:**
|
||||
[`BRIEF_APPENDIX_H_EN_15316_RESEARCH.md`](BRIEF_APPENDIX_H_EN_15316_RESEARCH.md).
|
||||
This is the document to hand to a research agent / human if BS EN
|
||||
15316-4-3:2017 access is available.
|
||||
|
||||
**Current investigation path:** the user is generating 3 simple
|
||||
solar-HW cert worksheets (A baseline, B high-Y, C low-Y) to
|
||||
empirically test whether the 1.81× ratio is systematic across all
|
||||
solar HW shapes or specific to cert 000565. Across 3 certs:
|
||||
~36 month-data-points should let us empirically fit any missing
|
||||
correction term. See "Continuation instructions" below.
|
||||
|
||||
## Open thread #2 — Elmhurst RdSAP solar HW collector defaults (RESOLVED)
|
||||
|
||||
Cert 000565 worksheet uses H3=4.0, H4=0.01 for "Solar collector
|
||||
details known: No". These don't match SAP 10.2 Table H1 (flat plate
|
||||
a1=3.5, a2=0).
|
||||
|
||||
**Source identified by sub-agent this session: RdSAP 10
|
||||
Specification §10.11 Table 29 "Heating and hot water parameters",
|
||||
row "Solar panel", page 58.** Verbatim:
|
||||
|
||||
> "If solar panel present, the parameters for the calculation not
|
||||
> provided in the RdSAP data set are:
|
||||
> - panel aperture area 3 m²
|
||||
> - **flat panel, η₀ = 0.80, a₁ = 4.0, a₂ = 0.01**
|
||||
> - facing South, pitch 30°, modest overshading
|
||||
> - …
|
||||
> - pump for solar-heated water is electric (75 kWh/year)
|
||||
> - showers are both electric and non-electric"
|
||||
|
||||
So RdSAP overrides the **input set** (a1, a2) but SAP 10.2's
|
||||
Appendix H is still the calculator. Our orchestrator uses the
|
||||
right Table 29 inputs (matching the worksheet), so this is **NOT**
|
||||
the source of the 1.81× over-count. The over-count is in the
|
||||
Appendix H formula itself.
|
||||
|
||||
This resolves a long-standing default-source mystery but doesn't
|
||||
help with the H24 over-count.
|
||||
|
||||
**Important:** changing H3/H4 to SAP Table H1 spec defaults makes
|
||||
the H24 over-count *worse* on cert 000565, not better.
|
||||
|
||||
## Open thread #3 — 12 gas-combi PV certs at +0.5-1.6 PE
|
||||
|
||||
S0380.73 cooking fix surfaced 12 gas-combi PV certs at residuals
|
||||
+0.5 to +1.6 PE (cohort-1 cert 2130 + 11 cohort-2). Pre-S0380.73 a
|
||||
compensating bug (the cooking over-count) masked this. Now visible
|
||||
but **no worksheets available** for these certs — same "unanchored
|
||||
chase" situation as the 5 SAP-residual certs. Re-pinned at current
|
||||
residuals; investigation deferred until worksheets land.
|
||||
|
||||
## Open thread #4 — 5 SAP-integer-residual certs
|
||||
|
||||
Total 14 |Δsap| points outstanding across 5 API-only certs (notes
|
||||
in `test_golden_fixtures.py`):
|
||||
|
||||
| Cert | Δsap | Shape |
|
||||
|---|---|---|
|
||||
| 0240 | −14 | Oil boiler + PV + RR |
|
||||
| 0390 | −7 | Oil boiler, 360m², age F masonry |
|
||||
| 6035 | −6 | Gas combi age A (pre-1900) |
|
||||
| 7536 | +1 | Multi-age extensions (D/L/F) |
|
||||
| 2130 | +1 | Shifted from 0 by S0380.73 cooking fix |
|
||||
|
||||
All API-only (no worksheets). User has agreed not to chase these
|
||||
without worksheet ground truth (per session discussion).
|
||||
|
||||
## How to run the baseline
|
||||
|
||||
```bash
|
||||
PYTHONPATH=/workspaces/model python -m pytest \
|
||||
backend/documents_parser/tests/test_summary_pdf_mapper_chain.py \
|
||||
backend/documents_parser/tests/test_elmhurst_extractor.py \
|
||||
backend/documents_parser/tests/test_elmhurst_end_to_end.py \
|
||||
domain/sap10_calculator/worksheet/tests/test_e2e_elmhurst_sap_score.py \
|
||||
domain/sap10_calculator/worksheet/tests/test_appendix_h_solar.py \
|
||||
domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py \
|
||||
domain/sap10_calculator/rdsap/tests/test_golden_fixtures.py \
|
||||
--no-cov -q
|
||||
```
|
||||
|
||||
Expected: **547 pass + 9 expected `test_sap_result_pin[000565-*]`
|
||||
fails**.
|
||||
|
||||
## Continuation instructions for next agent
|
||||
|
||||
The user is generating 3 solar-HW cert worksheets (A baseline, B
|
||||
high-Y, C low-Y) per the spec at end of this session. They'll land
|
||||
in `sap worksheets/Solar HW tests/` or similar. Each cert directory
|
||||
contains:
|
||||
- A Summary_NNNNNN.pdf
|
||||
- A P960-0001-NNNNNN.pdf (worksheet equivalent of dr87/U985)
|
||||
|
||||
### When the certs land
|
||||
|
||||
1. **Run the orchestrator** for each cert with the worksheet's H1-H8
|
||||
inputs:
|
||||
|
||||
```python
|
||||
from domain.sap10_calculator.worksheet.appendix_h_solar import (
|
||||
solar_water_heating_input_monthly_kwh,
|
||||
)
|
||||
from domain.sap10_calculator.worksheet.water_heating import (
|
||||
TABLE_J1_TCOLD_FROM_MAINS_C,
|
||||
)
|
||||
from domain.sap10_calculator.worksheet.solar_gains import Orientation
|
||||
from domain.sap10_calculator.climate.appendix_u import external_temperature_c
|
||||
|
||||
# H1-H8 from worksheet's Appendix H section (page 4 in U985 format)
|
||||
# (62)m monthly HW demand from worksheet
|
||||
# te from external_temperature_c(region, m) for region 0 (Block 1
|
||||
# SAP rating)
|
||||
result = solar_water_heating_input_monthly_kwh(...)
|
||||
```
|
||||
|
||||
2. **Extract worksheet (H24)m monthly values** from the cert's P960
|
||||
PDF page 4 (or wherever Block 1 sits) using:
|
||||
|
||||
```python
|
||||
from pypdf import PdfReader
|
||||
r = PdfReader(path_to_p960_pdf)
|
||||
# Look for (63c) "Solar input" row in the §4 HW section
|
||||
# Or (H24)m line directly in the Appendix H section
|
||||
```
|
||||
|
||||
3. **Build a 36-point dataset** (3 certs × 12 months) of (cascade
|
||||
H24, worksheet H24, X_cascade, Y_cascade, H17_cascade) and check:
|
||||
|
||||
- Does the per-month ratio show the same shape across all 3?
|
||||
(Summer ~1.7×, shoulder 3-4×) → confirms systematic bug.
|
||||
- Or does the ratio vary by cert? → suggests cert-specific input
|
||||
differences.
|
||||
|
||||
4. **Empirical fit attempt:** if the ratio pattern is systematic,
|
||||
try fitting:
|
||||
|
||||
```
|
||||
Qs_corrected = Qs_cascade × g(X, Y, H17)
|
||||
```
|
||||
|
||||
for various g shapes (multiplicative, additive,
|
||||
threshold-dependent). The fitted correction term + 3-cert
|
||||
validation gives us a temporary closure even without the EN
|
||||
standard.
|
||||
|
||||
5. **Decision point:** if empirical fit closes all 3 cert + cert
|
||||
000565 to <50 kWh/yr residual, ship as a spec-citation-pending
|
||||
slice (note in the commit + memory that it's empirical pending
|
||||
EN 15316-4-3 verification). Otherwise wait for the standard.
|
||||
|
||||
6. **Integration:** if cert 000565 HW gap closes via this work,
|
||||
wire the orchestrator into
|
||||
[`domain/sap10_calculator/worksheet/water_heating.py:943`](../worksheet/water_heating.py#L943)
|
||||
(currently hardcoded `solar_monthly_kwh=zero12`). This is the
|
||||
step that lets cert 000565's HW pin go from +272 → ~0.
|
||||
|
||||
### What NOT to do
|
||||
|
||||
- Don't redo the work the prior agent already verified:
|
||||
- Don't re-test H1-H8 input matching (verified)
|
||||
- Don't re-test polynomial coefficients (matches Table H3)
|
||||
- Don't re-test (H7) flux conversion (verified)
|
||||
- Don't re-test SAP spec formula transcription (verbatim)
|
||||
|
||||
- Don't chase the 12 gas-combi PV certs or the 5 SAP-residual certs
|
||||
without worksheets — user has explicitly de-prioritised those.
|
||||
|
||||
- Don't integrate the orchestrator into the cascade with the
|
||||
current 1.81× over-estimate — that would WORSEN cert 000565's HW
|
||||
residual from +272 → −131 per the handover prediction.
|
||||
|
||||
## Key files touched this session
|
||||
|
||||
| File | Touched in |
|
||||
|---|---|
|
||||
| `domain/sap10_calculator/rdsap/cert_to_inputs.py` | All 4 slices — new helpers + 4 rewires |
|
||||
| `domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py` | 5 new tests |
|
||||
| `domain/sap10_calculator/rdsap/tests/test_golden_fixtures.py` | 33 cluster pin updates across S0380.71-.73 |
|
||||
| `domain/sap10_calculator/docs/BRIEF_APPENDIX_H_EN_15316_RESEARCH.md` | NEW — research brief |
|
||||
| `domain/sap10_calculator/docs/HANDOVER_POST_S0380_73_APPENDIX_H_BLOCKED.md` | NEW — this doc |
|
||||
|
||||
## Spec source quick-reference
|
||||
|
||||
- **SAP 10.2 full specification**: `domain/sap10_calculator/docs/specs/sap-10-2-full-specification-2025-03-14.pdf`
|
||||
- Table 12d (monthly electric CO2 factors): p.195
|
||||
- Table 12e (monthly electric PE factors): p.196
|
||||
- Appendix H (solar thermal): p.74-78, Table H1 p.78, Table H3 p.78
|
||||
- Appendix L (cooking electricity L20): p.91
|
||||
- Appendix M1 §3a (D_PV definition): p.93-94
|
||||
- **S10TP-04** (BRE Appendix H change note): `domain/sap10_calculator/docs/specs/sap10 technical papers/S10TP-04 - Change to Appendix H to include solar space heating - V1_3.pdf`
|
||||
- **SAP 10.3** at `domain/sap10_calculator/docs/specs/sap-10-3-full-specification-2026-01-13.pdf`: **DO NOT reference** (project tracks 10.2 only per [[feedback-sap-10-2-only-never-10-3]]).
|
||||
219
domain/sap10_calculator/docs/NEXT_AGENT_PROMPT_POST_S0380_73.md
Normal file
219
domain/sap10_calculator/docs/NEXT_AGENT_PROMPT_POST_S0380_73.md
Normal file
|
|
@ -0,0 +1,219 @@
|
|||
# Next-agent prompt — post S0380.73
|
||||
|
||||
Branch: `feature/per-cert-mapper-validation`.
|
||||
HEAD: `c63d6740`.
|
||||
|
||||
Read these in order before any tool call:
|
||||
|
||||
1. [`HANDOVER_POST_S0380_73_APPENDIX_H_BLOCKED.md`](HANDOVER_POST_S0380_73_APPENDIX_H_BLOCKED.md) (full state)
|
||||
2. [`BRIEF_APPENDIX_H_EN_15316_RESEARCH.md`](BRIEF_APPENDIX_H_EN_15316_RESEARCH.md) (the unblock-this brief)
|
||||
|
||||
Also load these memories before starting:
|
||||
|
||||
- `project_cert_000565_recovery_state` — cert 000565 slice history
|
||||
- `project_golden_coverage_state` — cohort state + S0380.70-.73 closures
|
||||
- `feedback_sap_10_2_only_never_10_3` — **CRITICAL** — never reference SAP 10.3 spec
|
||||
- `feedback_verify_handover_claims` — verify spec citations before implementing
|
||||
- `feedback_spec_floor_skepticism` — "spec-precision floor" framing usually hides a real spec bug
|
||||
- `feedback_zero_error_strict` — pyright net-zero per touched file
|
||||
- `feedback_commit_per_slice` — one slice = one commit
|
||||
- `feedback_spec_citation_in_commits` — quote spec text + page in commit messages
|
||||
- `feedback_aaa_test_convention` — every new test uses `# Arrange / # Act / # Assert`
|
||||
- `feedback_e2e_validation_philosophy` — component pins at <1e-3; SAP integer delta=0; no adaptive ceilings
|
||||
|
||||
## State summary
|
||||
|
||||
**Cumulative session result:** test baseline went from 317 pass + 9
|
||||
expected fails → **547 pass + 9 expected fails**. The 9 expected
|
||||
fails are all `test_sap_result_pin[000565-*]` and reflect cert
|
||||
000565's residual gaps. Four cohort closure slices (S0380.70-.73)
|
||||
applied the SAP 10.2 Table 12d/12e header rule consistently to
|
||||
secondary heating, main heating, hot water, and the Appendix M1
|
||||
§3a D_PV cooking electricity formula.
|
||||
|
||||
The ASHP cohort cluster of 20 STANDARD-tariff certs compressed
|
||||
from mean PE residual −3.10 → −0.06 kWh/m² across these 4 slices.
|
||||
That cluster is now closed.
|
||||
|
||||
The remaining outstanding work is on cert 000565 (the wacky stress
|
||||
test). Two of cert 000565's biggest residuals (HW +272, space
|
||||
heating +266) are blocked on external data:
|
||||
|
||||
- **Appendix H Solar HW magnitude** (HW +272 kWh/yr cascade over):
|
||||
orchestrator at
|
||||
[`domain/sap10_calculator/worksheet/appendix_h_solar.py`](../worksheet/appendix_h_solar.py)
|
||||
produces 509.78 vs worksheet 281.35 = 1.81× over. All inputs
|
||||
verified, all SAP 10.2 spec formulas implemented verbatim. The
|
||||
bug is in a missing Method 2 clamp / validity envelope / useful-
|
||||
gain suppression that SAP didn't reproduce from BS EN 15316-4-3.
|
||||
|
||||
- **RR fold-in** (space_heating +266 kWh/yr): blocked on RdSAP §3.10
|
||||
detailed-RR geometry / area formula not in repo.
|
||||
|
||||
## Recommended next slice (the Appendix H empirical approach)
|
||||
|
||||
The user is generating 3 simple solar-HW cert worksheets to
|
||||
empirically test the 1.81× over-count. These will land in
|
||||
`sap worksheets/Solar HW tests/` (or similar) as:
|
||||
|
||||
- `A-baseline-south-modest/` (South, 30°, Modest overshading)
|
||||
- `B-highY-south-none/` (South, 30°, None/very-little overshading)
|
||||
- `C-lowY-north-significant/` (North or East, 60°, Significant
|
||||
overshading)
|
||||
|
||||
Each cert directory contains a `Summary_NNNNNN.pdf` and a
|
||||
`P960-0001-NNNNNN.pdf` (Elmhurst worksheet). All 3 certs share the
|
||||
same base envelope (28 Distillery Wharf, semi-detached, TFA 90 m²,
|
||||
age G, masonry cavity walls). Each cert has "Solar collector
|
||||
details known: No" so they all use RdSAP 10 Table 29 defaults
|
||||
(H3=4.0, H4=0.01 — verified in this session).
|
||||
|
||||
### When the certs land
|
||||
|
||||
1. **Run the orchestrator** for each cert. The probe pattern:
|
||||
|
||||
```python
|
||||
from domain.sap10_calculator.worksheet.appendix_h_solar import (
|
||||
solar_water_heating_input_monthly_kwh,
|
||||
)
|
||||
from domain.sap10_calculator.worksheet.water_heating import (
|
||||
TABLE_J1_TCOLD_FROM_MAINS_C,
|
||||
)
|
||||
from domain.sap10_calculator.worksheet.solar_gains import Orientation
|
||||
from domain.sap10_calculator.climate.appendix_u import external_temperature_c
|
||||
|
||||
# H1-H8 from worksheet's Appendix H section
|
||||
# (62)m monthly HW demand from worksheet (look for line ref (62))
|
||||
# external temps for region 1 (Thames Valley) Block 1 SAP rating
|
||||
te = tuple(external_temperature_c(1, m) for m in range(1, 13))
|
||||
|
||||
result = solar_water_heating_input_monthly_kwh(
|
||||
collector_orientation=Orientation.S, # or N/E per cert
|
||||
collector_pitch_deg=30.0, # or 60 per cert
|
||||
region=1,
|
||||
aperture_area_m2=3.0, # RdSAP Table 29 default
|
||||
zero_loss_efficiency=0.8,
|
||||
linear_heat_loss_a1=4.0, # RdSAP Table 29 default
|
||||
second_order_heat_loss_a2=0.01, # RdSAP Table 29 default
|
||||
loop_efficiency=0.9,
|
||||
incidence_angle_modifier=0.94,
|
||||
overshading_factor=0.8, # or 1.0 / 0.65 per cert
|
||||
overall_heat_loss_coefficient_from_test=6.5,
|
||||
dedicated_solar_storage_volume_l=...,
|
||||
combined_cylinder_total_volume_l=...,
|
||||
hot_water_demand_monthly_kwh=(62)m,
|
||||
wwhrs_monthly_kwh=(0.0,) * 12,
|
||||
cold_water_temperatures_monthly_c=TABLE_J1_TCOLD_FROM_MAINS_C,
|
||||
external_temperatures_monthly_c=te,
|
||||
solar_hot_water_only=True,
|
||||
)
|
||||
```
|
||||
|
||||
2. **Extract worksheet (H24)m monthly** from each cert's P960 PDF.
|
||||
For cert 000565 the (H24)m values are on page 4 (Block 1 SAP
|
||||
rating). Look for line `(63c)` solar input row (12 monthly
|
||||
values, negative sign convention) — its absolute value equals
|
||||
(H24)m. Or find `Heat delivered to hot water` row with `(H24)`
|
||||
label at the end.
|
||||
|
||||
3. **Build a 36-point dataset** of `(cascade_H24, worksheet_H24,
|
||||
X_cascade, Y_cascade, H17_cascade)` across the 3 certs.
|
||||
|
||||
4. **Diagnostic analysis:**
|
||||
|
||||
- Does the per-month ratio show the same shape across all 3?
|
||||
(Summer 1.5-1.7×, shoulder 3-4×) → confirms the bug is in the
|
||||
formula, not in cert 000565's specific inputs.
|
||||
- Does the ratio vary with Y? Plot ratio vs Y to look for a
|
||||
threshold (sharp transition).
|
||||
- Does the ratio vary with X? Plot ratio vs X to look for an
|
||||
envelope.
|
||||
|
||||
5. **Empirical fit attempt** (if ratio pattern is systematic):
|
||||
try candidate corrections in this order:
|
||||
|
||||
- **Threshold on Y:** if Y < Y_min, set Qs = 0. Fit Y_min from
|
||||
data (shoulder months that worksheet zeroes give the
|
||||
threshold).
|
||||
- **Useful gain factor:** Qs_corrected = Qs × max(0, 1 − k/Y).
|
||||
Fit k.
|
||||
- **X-validity clamp:** if X > X_max, apply a different rule.
|
||||
- **Tank loss subtraction:** Qs_corrected = Qs − k·H17. Fit k.
|
||||
|
||||
6. **Decision point:**
|
||||
|
||||
- **If empirical fit closes all 3 certs + cert 000565 to <50
|
||||
kWh/yr residual:** ship as a spec-citation-pending slice with
|
||||
`# TODO(EN-15316-verification)` comments + commit message
|
||||
noting empirical-pending. Update
|
||||
[`BRIEF_APPENDIX_H_EN_15316_RESEARCH.md`](BRIEF_APPENDIX_H_EN_15316_RESEARCH.md)
|
||||
with the fitted-correction findings so a future research
|
||||
trip can verify.
|
||||
- **Otherwise:** hold and wait for BS EN 15316-4-3:2017 access.
|
||||
Document the failed-fit attempts in the brief.
|
||||
|
||||
### Cert 000565 HW integration (only after the formula bug closes)
|
||||
|
||||
Wire the orchestrator into
|
||||
[`domain/sap10_calculator/worksheet/water_heating.py:943`](../worksheet/water_heating.py#L943)
|
||||
which currently hardcodes `solar_monthly_kwh=zero12`. This is the
|
||||
step that lets cert 000565's HW pin go from +272 → ~0.
|
||||
|
||||
**DO NOT integrate the orchestrator at the current 1.81× over-
|
||||
estimate.** The handover predicts this would *worsen* cert 000565's
|
||||
HW residual from +272 → −131 (overshoot in the negative direction).
|
||||
|
||||
## What NOT to do
|
||||
|
||||
- Don't re-verify the work the prior agent already verified:
|
||||
- H1-H8 input matching to worksheet (verified to 4 d.p.)
|
||||
- Polynomial coefficients vs Table H3 (verbatim match)
|
||||
- (H7) flux conversion vs Appendix U §U3.3 (verified)
|
||||
- SAP spec formula transcription (verbatim)
|
||||
- The H3=4.0, H4=0.01 default source (RdSAP 10 §10.11 Table 29
|
||||
p.58 — found this session)
|
||||
- ChatGPT-mediated research on EN 15316-4-3 already established
|
||||
the polynomial coefficients match the prEN draft Table B.1
|
||||
(so the polynomial isn't the bug)
|
||||
- Don't chase the 12 gas-combi PV certs or the 5 SAP-residual certs
|
||||
without worksheets — user has explicitly de-prioritised those.
|
||||
- Don't reference SAP 10.3 ([[feedback-sap-10-2-only-never-10-3]]).
|
||||
|
||||
## Standard workflow per slice
|
||||
|
||||
1. Read SAP 10.2 spec page for the change — quote it in commit
|
||||
2. Probe current cascade output, identify exact spec-vs-cascade gap
|
||||
3. Write failing test FIRST (AAA structure)
|
||||
4. Implement helper / change
|
||||
5. Verify test passes
|
||||
6. Run full handover suite (command in handover doc)
|
||||
7. Check pyright on touched files — net-zero from baseline
|
||||
8. Commit with spec citation
|
||||
9. Update relevant memory if state changed
|
||||
|
||||
## How to run the baseline
|
||||
|
||||
```bash
|
||||
PYTHONPATH=/workspaces/model python -m pytest \
|
||||
backend/documents_parser/tests/test_summary_pdf_mapper_chain.py \
|
||||
backend/documents_parser/tests/test_elmhurst_extractor.py \
|
||||
backend/documents_parser/tests/test_elmhurst_end_to_end.py \
|
||||
domain/sap10_calculator/worksheet/tests/test_e2e_elmhurst_sap_score.py \
|
||||
domain/sap10_calculator/worksheet/tests/test_appendix_h_solar.py \
|
||||
domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py \
|
||||
domain/sap10_calculator/rdsap/tests/test_golden_fixtures.py \
|
||||
--no-cov -q
|
||||
```
|
||||
|
||||
Expected: **547 pass + 9 expected `test_sap_result_pin[000565-*]`
|
||||
fails** (the 9 cert 000565 cascade-gap pins).
|
||||
|
||||
## Memory hygiene
|
||||
|
||||
After the next slice, update:
|
||||
|
||||
- `project_cert_000565_recovery_state` — add Appendix H magnitude
|
||||
outcome (empirical fit landed, or wait-for-EN documented).
|
||||
- `project_golden_coverage_state` — HEAD update.
|
||||
|
||||
Good luck.
|
||||
Loading…
Add table
Reference in a new issue