Model/domain
Khalim Conn-Kowlessar 51d8f65aac fix(pcdb): extend heat-pump efficiency toward 100% beyond table PSR range 🟩
interpolate_heat_pump_efficiency_at_psr clamped to the smallest/largest PSR
row when the dwelling's plant size ratio fell outside the record's range.
That is the SAP 10.2 Appendix N rule for *combined heat-pump-and-boiler*
packages, not for a plain air/ground/water source heat pump.

Per Appendix N2 (PDF p.101, footnotes 44/45) a source heat pump whose PSR
exceeds the record's largest value takes a reciprocal-linear interpolation
between the largest-PSR efficiency and 100% at twice that PSR (100% beyond),
and 100% when the PSR is below the record's smallest value. Both the space-
and water-heating PSR-dependent efficiencies extend this way.

Effect: an oversized heat pump in a small dwelling is no longer credited the
full top-of-table COP. Accredited Elmhurst worksheet for cert 100110101713
(golden fixture case 56, PCDB 100061, PSR 3.107 over largest 2.0): (206)
334.4% -> 139.66% = Elmhurst exact. Corpus (RdSAP-21.0.1, n=1000) MAE
0.7397 -> 0.7258, within-0.5 0.7410 held; only two certs move (both
oversized-PSR heat pumps), 100110101713 +18.32 -> -4.97.

Exhaust-air and combined heat-pump-and-boiler packages have different
boundary rules (straight-to-100% / clamp-to-edge) but are not distinguished
by the current PCDB parse; the air/ground/water rule is applied uniformly,
a documented limitation noted in the function docstring.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-29 15:13:16 +00:00
..
addresses standardist Address 2026-05-22 10:13:32 +00:00
billing Route an off-peak meter's electric end uses to the day/night carrier 🟩 2026-06-24 17:38:37 +00:00
data_transformation moved classifier data transformation to an easy one 2026-06-01 14:53:34 +00:00
elmhurst more examples 2026-06-19 09:51:49 +00:00
epc fix(overlay): synthesise a coherent gas-boiler heating system on Landlord Override 2026-06-26 12:48:33 +00:00
epc_prediction Predict ventilation kind from the cohort mode 🟩 2026-06-26 10:54:11 +00:00
fuel_rates Expose an off-peak meter's standing charge and full day/night blend range 🟩 2026-06-24 17:14:51 +00:00
geospatial feat(geospatial): one-read spatial reference (coords + restrictions) 2026-06-04 17:13:39 +00:00
magicplan add todo comment for named ranges 2026-06-10 13:32:11 +00:00
modelling fix(pv): credit PV only when connected to the dwelling's meter 🟩 2026-06-29 13:40:51 +00:00
property feat: thread physical-state-change signal into rebaselining 🟩 2026-06-26 19:15:11 +00:00
property_baseline feat: rebaseliner adopts calc output on physical-state change 🟩 2026-06-26 19:09:55 +00:00
sap10_calculator fix(pcdb): extend heat-pump efficiency toward 100% beyond table PSR range 🟩 2026-06-29 15:13:16 +00:00
sap10_ml test(pv): credit PV only when connected to dwelling meter (pv_connection) 🟥 2026-06-29 13:32:20 +00:00
tasks new application to trigger e2e for a single property and scenario 2026-06-22 12:54:53 +00:00
building_geometry.py feat(modelling): floor Recommendation Generator + ground-floor-area geometry 2026-06-03 09:12:29 +00:00
postcode.py get rid of comments 2026-05-20 13:21:11 +00:00