nx_hvac_efficiency.nx

nx_hvac_efficiency.nx -- INDEPENDENT HVAC efficiency verdict from out-of-band sensor readings (the thermostat cannot fake this). Operator ask (2026-06-23): "get our hvac efficiency s class measured in our iot so that when we use our therm we can measure independently how effective the systems are working." Architecture (operator-chosen): broad / multi-system; the independent runtime + power signal comes from a whole-panel CT monitor (Emporia Vue / Sense class), so on/off is the HVAC circuit drawing current -- NOT the thermostat's self-report. THE EXCEED: a vendor thermostat reports comfort + schedule ("at setpoint, all good"). A CT monitor reports energy. NEITHER emits a physics-grounded verdict on whether the equipment is actually working well. This organ does, from signals the thermostat does not control: - SHORT_CYCLING -> oversizing (cycles/hr too high; high humidity, wear, "feels hot at 72") -- the vendor hides this - DEGRADED_CAPACITY -> it runs but barely moves temp (fouled coil, low charge, dirty filter) -- the vendor says "heating..." - POOR_TRACKING -> overshoots the setpoint (bad control loop) = a verdict a happy thermostat would never give you. This is the R1 CORE: it needs only ONE independent indoor temp sensor + the runtime flag, so it works for ANY system type (forced-air, heat pump, mini-split, window) before any per-vendor power math (R3/R4 COP) lands. NO-FLOAT: everything is integer (milli-degC, seconds, permille, x10 rates) per the ecosystem integer-only doctrine. No syscalls -> deterministic + hard-gateable with a canned trace. NEVER-BRICK (CLAUDE.md #26): efficiency MEASUREMENT is read-only by construction -- this organ reads samples and emits a verdict; it writes nothing to any device, thermostat, or firmware. There is no firmware path here to prove safe because none exists. (Any future active-recovery TEST that commands a setpoint is a SEPARATE organ that must restore the prior setpoint + fail-safe; it is deliberately NOT in this read-only core.) genealogy_id: project-iot-discovery-pairing-revival-2026-06-22 (R-HVAC.1) + project-ac-footprint-and-hvac-refurb (short-cycle/oversize) license_tier: ORIGINAL