Point Dictionary: ERV

Energy recovery ventilator point dictionary. Exhaust-side, supply/exhaust airflow, and generic command/status classes verified in Brick 1.4.4. ASHRAE 223 terms were checked against ontology artifact 223p-1.0.0-ppr2.1.ttl (owl:versionInfo 1.0.0-ppr.2.1; SHA-256 1f156f9938c0be430d2216e01e31bb183c438ba318d8d4a23d2f074ebcd6f573), not an inferred final 2026 release label. The post-recovery outdoor-air temperature and technology-specific active-recovery attachments are provisional. ERV-0001 uses three ERV-local temperatures; ERV-0002/0003 use the site OAT and actual frost state; ERV-0004 requires a final command plus independent physical proof; ERV-0005 requires comparable post-recovery supply and building-exhaust flow measurements.

erv_oa_entering_temp

Outdoor air temperature entering the ERV (upstream of recovery)

• 223P: Sensor observes QuantifiableObservableProperty at the ERV outdoor-air inlet via hasProperty
• QUDT unit: DEG_C

brick:Outside_Air_Temperature_Sensor (verified via the AHU oat entry); position it upstream of the wheel/exchanger. The effectiveness denominator is (erv_exhaust_temp - this), so its accuracy bounds ERV-0001 directly.

erv_oa_leaving_temp

Outdoor air temperature leaving the ERV (downstream of recovery, before coils)

• 223P: Sensor observes QuantifiableObservableProperty at the ERV outdoor-air outlet via hasProperty
• QUDT unit: DEG_C

No Brick 1.4.4 class names the post-recovery OA temperature (heat-exchanger entering/leaving classes exist only for water); tag the generic air-temperature sensor pattern on the ERV supply outlet. This is the effectiveness numerator’s moving term.

erv_exhaust_temp

Exhaust air temperature entering the ERV from the building

• 223P: Sensor observes QuantifiableObservableProperty at the ERV exhaust inlet via hasProperty
• QUDT unit: DEG_C

brick:Exhaust_Air_Temperature_Sensor grep-verified in Brick 1.4.4. Bind the building-side (entering) exhaust temperature, not the discharge after recovery.

oat

Outdoor air temperature

• 223P: Sensor observes QuantifiableObservableProperty at the outdoor-air intake
• QUDT unit: DEG_C

Brick spelling is Outside_ (Outdoor_Air_Temperature_Sensor does not exist). Role-OutdoorAirIntake is 223P’s only outdoor role; used by reference instance oa-temp. [ERV dictionary] Brick class and 223P pattern carried over (equipment-independent); consumed by ERV-0002’s frost test; on many units the same physical sensor as erv_oa_entering_temp.

erv_frost_prot

Frost protection active (true while the frost sequence is engaged)

• 223P: EnumeratedObservableProperty (Binary-OnOff) on the frost-protection sequence

No Brick 1.4.4 class; bind the BAS frost-protection status (preheat stage, wheel speed reduction, or bypass modulation — whichever the unit uses).

erv_enabled

ERV enabled/commanded on

• 223P: EnumeratedObservableProperty (Binary-OnOff) on the ERV via hasProperty

brick:Enable_Status grep-verified in Brick 1.4.4.

erv_recovery_cmd

Final command to operate the ERV’s active recovery device

• 223P: EnumeratedActuatableProperty on the active recovery component via hasProperty

brick:Start_Stop_Command is exact and equipment-agnostic in Brick 1.4.4, but the owning active component is technology-specific and therefore provisional here: attach to the wheel drive, runaround pump, or other commanded recovery component, not merely to the ERV enable. This is the FINAL command after frost, bypass, smoke, and safety logic; an upstream request can disagree with correct internal sequencing and manufacture ERV-0004. ASHRAE 223 uses an EnumeratedActuatableProperty with Binary-OnOff on that component.

erv_recovery_status

Independent proof that the ERV’s active recovery device is operating

• 223P: EnumeratedObservableProperty on the active recovery component via hasProperty

Brick 1.4.4 has no recovery-wheel run-status class; generic brick:On_Off_Status is the honest cross-technology mapping and the equipment attachment is provisional. Bind independent physical proof: wheel rotation/speed above its commissioned minimum, runaround-pump current/flow proof, or equivalent. A command echo or auxiliary point sourced from the same relay is not proof and makes ERV-0004 structurally blind.

erv_supply_airflow

Post-recovery supply stream airflow through the energy-recovery device

• 223P: FlowSensor observes QuantifiableObservableProperty at the ERV connection point with hasRole Role-Supply
• QUDT unit: L-PER-SEC

brick:Supply_Air_Flow_Sensor is exact in Brick 1.4.4 for the post-recovery supply side. An upstream intake measurement is brick:Outside_Air_Flow_Sensor and is not interchangeable where bypass or leakage exists. In ASHRAE 223, location and Role-Supply live on the ERV connection point/topology (the role is not a property aspect); the FlowSensor observes a VolumeFlowRate property in L/s. Bind the stream actually traversing the recovery device, on the same averaging basis as erv_exhaust_airflow.

erv_exhaust_airflow

Building exhaust stream airflow through the energy-recovery device

• 223P: FlowSensor observes QuantifiableObservableProperty at the ERV connection point with hasRole Role-Exhaust
• QUDT unit: L-PER-SEC

brick:Exhaust_Air_Flow_Sensor is exact in Brick 1.4.4. In ASHRAE 223, location and Role-Exhaust live on the ERV connection point/topology (the role is not a property aspect). Bind the building-exhaust stream at a location comparable to erv_supply_airflow and with the same sign convention and averaging interval; ERV-0005 requires finite, nonnegative L/s values and does not repair reversed sensor polarity.