The Heating/cooling state determination (HCStaDtr) compares room temperature to current setpoints and checks whether any HVAC devices are under active PID control. The heating / cooling state is identified (Heating, Cooling, or Neither) and supplied to the BACnet object HCSta. The H/C status is also displayed on the room operating unit. Additional relevant BACnet objects (owned by other AFs) are shown in the table below.

To change status by temperature, the room temperature heating/cooling controllers must be inactive and the room temperature must be appropriate (high enough or low enough) to activate the switch-on delay timer, DlyOnHCChovr (Switch-on delay for heat/cool.changeover). See Configuration.

Description

Object

Pre-loaded Values

Room temperature setpoint shift

SpTRShft [RM TEMP SHFT]

0.0

Present cooling setpoint for comfort

SpCCmf [CMF CLG STPT]

75ºF (25ºC)

Delta cooling setpoint for pre-comfort

DSpCPcf [STBY C DELTA]

2ºF (1ºC)

Present cooling setpoint for economy

SpCEco [ECO CLG STPT]

85ºF (30ºC)

Cooling setpoint for protection

SpCPrt [PROT CLG STPT]

104 ºF (40ºC)

Present heating setpoint for comfort

SpHCmf [CMF HTG STPT]

70ºF (21ºC)

Delta heating setpoint for pre-comfort

DSpHPcf [STBY H DELTA]

2ºF (1ºC)

Present heating setpoint for economy

SpHEco [ECO HTG STPT]

55ºF (12ºC)

Heating setpoint for protection

SpHPrt [PROT HTG STPT]

45 ºF (7ºC)

Present cooling setpoint

PrSpC [CLG STPT EFF]

----

Present heating setpoint

PrSpH [HTG STPT EFF]

----

Present operating mode

PrOpMod [OP MODE EFF]

Comfort

Room operating mode

ROpMod [RM OP MODE]

Comfort

Plant operating mode

PltOpMod [PLANT OPMODE]

Comfort

Room temperature setpoint (for display on room unit)

SpTR [RM TEMP STPT]

----

Room temperature

TR [RM TEMP EVAL]

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