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For any cert lodging a Table 362 heat-pump PCDB record, the cascade now replaces the Table 4a category defaults with PSR-interpolated efficiencies per SAP 10.2 Appendix N (PDF p.108): (206) = 0.95 × η_space,1_interp (N3.6 in-use factor) (217) = in_use_factor × η_water,3_interp (N3.7(a) + footnote 49) where η_space,1 and η_water,3 are PSR-dependent values from the PCDB record's PSR-group table (decoded in slice 102c.2), and the dwelling's PSR is computed per PDF p.100 line 5946-5950: PSR = max_nominal_output_kw / (HLC_annual_avg_W_per_K × 24.2 K / 1000) The N3.7 in-use factor (PDF p.6097) tests three cylinder criteria: 1. cert volume ≥ PCDB volume 2. cert heat-exchanger area ≥ PCDB area (unless PCDB area = 0 per fn53) 3. cert heat loss [(47)×(51)×(52)] ≤ PCDB heat loss All three pass → 0.95; any criterion fails or is unknown → 0.60. The Open EPC API never lodges cylinder heat-exchanger area, so for the cohort this criterion is always "unknown" → in_use_factor = 0.60. Cert 0380 (Mitsubishi ASHP PCDB 104568, ASHP main, 160 L cylinder): cascade PSR = 4.39 / (127.158 × 24.2 / 1000) ≈ 1.4266 cascade η_space,1_interp ≈ 235.24 (PSR-1.2 row 253.9, PSR-1.5 229.2) cascade η_water,3_interp ≈ 285.13 (PSR-1.2 row 287.7, PSR-1.5 284.3) cascade main_heating_eff ≈ 2.2348 (vs worksheet 2.2305, 1.9e-3 diff) cascade HW kWh/yr ≈ 878.05 (vs worksheet 877.97, 0.08 kWh/yr) cascade SAP rating ≈ 89.11 (vs worksheet 88.5104, +0.60) The remaining +0.60 SAP residual is bounded by the ~0.4% PSR-formula drift (the cascade computes PSR=1.4266 from (39)_annual_avg × 24.2 K whereas the worksheet back-solves to ≈ 1.4321). Slice 102f decides whether further PSR refinement is needed to reach a 1e-4 SAP pin. |
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| .. | ||
| addresses | ||
| data_transformation | ||
| epc | ||
| sap10_calculator | ||
| sap10_ml | ||
| tasks | ||
| postcode.py | ||