Heating and Cooling Simultaneously

Objective/Method/Outcome

Objective: Determines if a heating and cooling control sequence overlap exists.

Method: Checks if the HCV and the CCV are both open while the unit is on.

Outcome: Generates an insight if the amount of time the HCV and CCV are open simultaneously in a week exceeds the allowable hours threshold.

Description

Determine if a heating and cooling control sequence overlap exists by checking if the heating coil valve and the cooling coil valve are both open while the unit is on.

Default Priority

High

  1. Error in control sequence. Review and modify programmed sequence of operation.
  2. Automatic control has been overridden. Revert equipment back to automatic control.

Message

The heating coil valve and cooling coil valve are simultaneously open for over 4 hours in the week. Review and modify programmed sequence of operation.

Rule Template Type

Insight Type: Fault Detection

Trigger Type: Active High

Logic

Determine if heating and cooling control is overlapping
Logic used to determine if heating and cooling control is overlapping

Inputs

InputsUnitsDefault ValueTagsDescription
Cooling Coil Valve% cmd, cool, water, valveCooling coil valve position (command or feedback)
Heating Coil Valve% cmd, heat, water, valveHeating coil valve position (command or feedback)
Equipment Status  fan, status|cmdUnit on status. Alternatively, building occupancy can be used
Const. – Valve Open Threshold%2 Value above which the coil valve is considered open
Const. – Allowable Hours per Weekhrs4 The acceptable hours of overlap per week

Notes

Not valid for systems using the cooling coil for de-humidification as well as cooling.Default logic flow is designed for % open, where the CCV/HCV is considered open beyond 2%Default Constants:

  • Const. – Valve Open Threshold [%]: 2
  • Const. – Acceptable Hours per Week [hrs]: 4

CTL Generated:

  • Weekly Hours CCV/HCV Overlap
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