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VAV

There are a number of variations on a VAV that are found in buildings. A hierarchy of validation is described here, with a minimum set of requirements that every VAV must meet, as well as a series of finer requirement that describe each variation.

This document currently focuses on validating an entity given a class. A future operating state would better be an iterative validation and classification scheme, where we first classify something as a base VAV, before iterating down to the finest classification shape it satisfies.

Variations

  • Base VAV (minimum spec)
    • Single Duct
      • Single Duct with Reheat
    • Dual Duct
    • Fan Powered
      • Fan Powered Series
      • Fan Powered Parallel
    • Bypass

Diagrams

Single Duct
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wcrd 2021
network
network
discharge
discharge
Controller
Controller
Discharge Air Temperature Setpoint
Discharge Air Temperature Setpoint
Discharge Air Temperature
Discharge Air Temperature
Discharge Air Flow
Discharge Air Flow
Entering Air Temperature
Entering Air Temperature
Position
Position
Position Command
Position Command
Occupancy Status
Occupancy Status
Mode
Mode
Zone
Zone
Zone Air Temperature
Zone Air Temperature
Zone Air Temperature Setpoint
Zone Air Temperature Setpoint
Terminal Load
Terminal Load
Discharge Damper
Discharge Damper
Viewer does not support full SVG 1.1
Dual Duct
Hot Deck Entering Air Temperature
Hot Deck Entering Air Temperature
Controller
Controller
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wcrd 2021
hot deck
hot deck
cold deck
cold deck
discharge
discharge
Discharge Air Temperature Setpoint
Discharge Air Temperature Setpoint
Discharge Air Temperature
Discharge Air Temperature
Discharge Air Flow
Discharge Air Flow
Zone
Zone
Hot Deck Entering Air Flow
Hot Deck Entering Air Fl...
Cold Deck Entering Air Temperature
Cold Deck Entering Air Temperature
Cold Deck Entering Air Flow
Cold Deck Entering Air Flow
Occupancy Status
Occupancy Status
Mode
Mode
Zone Air Temperature
Zone Air Temperature
Zone Air Temperature Effective Setpoint
Zone Air Temperature Effective Setpoint
Terminal Load
Terminal Load
Zone Air Temperature Effective Heating Setpoint
Zone Air Temperature Effective Heating Setpo...
Zone Air Temperature Effective Cooling Setpoint
Zone Air Temperature Effective Cooling Setpoi...
Position
Position
Position Command
Position Command
Cold Deck Damper
Cold Deck Damper
Position
Position
Position Command
Position Command
Hot Deck Damper
Hot Deck Damper
Viewer does not support full SVG 1.1
Fan Powered
Position
Position
Position Command
Position Command
Primary Air Damper
Primary Air Damper
Enable Command
Enable Command
Modulation
Modulation
Electric Heater
Electric Heater
Run Command
Run Command
Speed
Speed
Discharge Fan
Discharge Fan
Speed Command
Speed Command
Controller
Controller
Occupancy Status
Occupancy Status
Mode
Mode
Electric Heat
Electric Heat
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wcrd 2021
network
network
induced*
induced*
Entering Air Temperature
Entering Air Temperature
Entering Air Flow
Entering Air Flow
Return Air Temperature
Return Air Temperature
Return Air Flow
Return Air Flow
discharge
discharge
Zone
Zone
Zone Air Temperature
Zone Air Temperature
Zone Air Temperature Effective Setpoint
Zone Air Temperature Effective Setpoint
Terminal Load
Terminal Load
Zone Air Temperature Effective Heating Setpoint
Zone Air Temperature Effective Heating Setpo...
Zone Air Temperature Effective Cooling Setpoint
Zone Air Temperature Effective Cooling Setpoi...
Discharge Air Flow Cooling High Limit Setpoint
Discharge Air Flow Cooling High Limit Setpoi...
Discharge Air Flow Heating High Limit Setpoint
Discharge Air Flow Heating High Limit Setpo...
Discharge Air Temperature
Discharge Air Temperature
Discharge Air Flow
Discharge Air Flow
Discharge Air Temperature Setpoint
Discharge Air Temperature Setpoint
Discharge Air Flow Low Limit Setpoint
Discharge Air Flow Low Limit Setpoint
Viewer does not support full SVG 1.1
Bypass
wcrd 2021
wcrd 2021
network
network
discharge
discharge
Controller
Controller
Discharge Air Temperature Setpoint
Discharge Air Temperature Setpoint
Discharge Air Temperature
Discharge Air Temperature
Discharge Air Flow
Discharge Air Flow
Entering Air Temperature
Entering Air Temperature
Position
Position
Position Command
Position Command
Occupancy Status
Occupancy Status
Mode
Mode
Zone
Zone
Zone Air Temperature
Zone Air Temperature
Zone Air Temperature Setpoint
Zone Air Temperature Setpoint
Terminal Load
Terminal Load
Discharge Damper
Discharge Damper
Viewer does not support full SVG 1.1

Composition

Core

Base VAV

  • VAV must have a damper as a direct part.
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    classOrSubClassOf: brick:Damper
    ]

Single Duct

  • Inherits all requirements from Base VAV.

Single Duct with Reheat

  • Inherits all requirements from Single Duct VAV.
  • VAV must have a subclass of Heating Coil (primarily Hot Water Coil or an Electric Heating Coil).
    • Method 1 - subclass of heating coil
      path: brick:hasPart
      pathRequirements: [
      pathDistance: 1
      ]
      validationType: propertiesOfValues
      properties: [
      classOrSubClassOf: brick:Heating_Coil
      ]
    • Method 2 - explicit coil type
      path: brick:hasPart
      pathRequirements: [
      pathDistance: 1
      ]
      validationType: propertiesOfValues
      properties: [
      or (
      class: brick:Hot_Water_Coil,
      class: switch:Electric_Heating_Coil
      )
      ]
  • If VAV has Hot Water Coil, it must also have a Hot Water Valve THIS IS ON HOLD: We are determining best way to link the Valve to the VAV currently (part or other relationship)
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    classOrSubClassOf: brick:Hot_Water_Valve
    ]

We can represent this by requiring the VAV to have either:

  • Electric Heating Coil
    OR
  • Hot Water Coil AND Hot Water Valve
    • Could store this as a subshape (Terminal Unit HHW Heating bundle)

NOTE: Add class switch:Electric_Heating_Coil

Dual Duct

  • Inherits all requirements from Base VAV.
  • VAV must have 2 dampers as direct parts.
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: qualifiedValuesOfProperties
    properties: [
    classOrSubClassOf: brick:Damper
    ]
    qualifiers: [
    min-count: 2
    max-count: 2
    ]

Fan Powered

  • Inherits all requirements from Base VAV.
  • VAV must have a Fan as a direct part.
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    classOrSubClassOf: brick:Fan
    ]
  • VAV must have a subclass of Heating Coil (primarily Hot Water Coil or an Electric Heating Coil).
    • See validation steps described in Single Duct with Reheat

Fan Powered: Series & Parallel

We do not have an explicit method for determining differences. Technically, we could separate via the fan 'air stream':

  • Parallel: Return Fan
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    class: brick:Return_Fan
    ]
  • Series: Discharge Fan
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    class: brick:Discharge_Fan
    ]

Currently we are just using 'Fan'. We can add this validation soon.

Bypass VAV

This is technically the same componentry as the Base VAV. The method for differentiation is the same as for the Series and Parallel boxes - providing a more detailed subclass for the components.

  • VAV must have a Bypass Damper
    path: brick:hasPart
    pathRequirements: [
    pathDistance: 1
    ]
    validationType: propertiesOfValues
    properties: [
    class: brick:Bypass_Damper
    ]

Switch

Nil

Relationships

A VAV should be fed by some air distribution network or from major airside equipment (AHU, DOAS, MAU).

This is not currently being validated.

Core

Nil

Switch

Nil

Points

{ Rules around points for each variation; must include at least the following: All, Minimum Set}

All

An entity of this type is expected to have a selection of points from this provided list. Any points assigned that are not on this list will throw a warning.

switch:hasPointNamesh:class
Run CommandOn_Off_Command
Run StatusOn_Off_Status
Enable CommandEnable_Command
Enable StatusEnable_Status
ModeMode_Status
Occupancy CommandOccupancy_Command
Occupancy ModeOccupied_Mode_Status
Override Modeswitch:OverrideMode Status
Out of Service Statusswitch:Maintenance_Mode_Enable_Status
Power Supply Status
Fault Mode | Alarm Modeswitch:Fault_Mode_Status
Fault Status | Alarm StatusFault_Status
Discharge Air TemperatureDischarge_Air_Temperature_Sensor
Discharge Air Temperature SetpointDischarge_Air_Temperature_Setpoint
Discharge Air Temperature High Limit Setpointswitch:Discharge_Air_Temperature_High_Limit_Setpoint
Discharge Air Temperature Low Limit Setpointswitch:Discharge_Air_Temperature_Low_Limit_Setpoint
Discharge Air Temperature Unnoccupied Cooling Setpointswitch:Unoccupied Discharge Air Temperature Setpoint
Discharge Air Temperature Occupied Cooling Setpointswitch:Occupied Discharge Air Temperature Setpoint
Discharge Air Temperature Occupied Heating Setpointswitch:Occupied Discharge Air Temperature Heating Setpoint
Discharge Air Temperature Unnoccupied Heating Setpointswitch:Unoccupied Discharge Air Temperature Heating Setpoint
Discharge Air HumidityDischarge_Air_Humidity_Sensor
Discharge Air Humidity SetpointDischarge_Air_Humidity_Setpoint
Discharge Air Absolute Humidityswitch:Discharge_Air_Absolute_Humidity_Sensor
Discharge Air PressureDischarge_Air_Static_Pressure_Sensor
Discharge Air Pressure SetpointDischarge_Air_Static_Pressure_Setpoint
Discharge Air Pressure High Limit Setpointswitch:Discharge_Air_Static_Pressure_High_Limit_Setpoint
Discharge Air Pressure Low Limit Setpointswitch:Discharge_Air_Static_Pressure_Low_Limit_Setpoint
Discharge Air Velocity Pressure
Discharge Air Dew Point TemperatureDischarge_Air_Dewpoint_Sensor
Discharge Air Dew Point Temperature Setpointswitch:Discharge_Air_Dewpoint_Setpoint
Discharge Air FlowDischarge_Air_Flow_Sensor
Discharge Air Flow SetpointDischarge_Air_Flow_Setpoint
Discharge Air Flow Status
Discharge Air Velocityswitch:Discharge_Air_Velocity_Sensor
Discharge Air Flow High Limit Setpointswitch:Discharge_Air_Flow_High_Limit_Setpoint
Discharge Air Flow Low Limit Setpointswitch:Discharge_Air_Flow_Low_Limit_Setpoint
Discharge Air Flow Cooling High Limit Setpointswitch:Cooling_Discharge_Air_Flow_High_Limit_Setpoint
Discharge Air Flow Cooling Low Limit Setpointswitch:Cooling_Discharge_Air_Flow_Low_Limit_Setpoint
Discharge Air Flow Heating High Limit Setpointswitch:Heating_Discharge_Air_Flow_High_Limit_Setpoint
Discharge Air Flow Heating Low Limit Setpointswitch:Heating_Discharge_Air_Flow_Low_Limit_Setpoint
Entering Air Temperatureswitch:Entering_Air_Temperature_Sensor
Entering Air Dew Point Temperature
Entering Air Dew Point Temperature Setpoint
Entering Air Flow
Entering Air Flow Setpoint
Entering Air Velocity
Max Entering Air Flow Setpoint
Min Entering Air Flow Setpoint
Hot Deck Entering Air Temperatureswitch:Entering_Air_Temperature_Sensor
Neutral Deck Entering Air Temperature
Cold Deck Entering Air Temperature
Hot Deck Entering Air Flowswitch:Entering_Air_Flow_Sensor
Hot Deck Entering Air Flow Setpointswitch:Entering_Air_Flow_Setpoint
Hot Deck Entering Air Flow High Limit Setpoint
Hot Deck Entering Air Flow Low Limit Setpoint
Cold Deck Entering Air Flowswitch:Entering_Air_Flow_Sensor
Cold Deck Entering Air Flow Setpointswitch:Entering_Air_Flow_Setpoint
Cold Deck Entering Air Flow High Limit Setpoint
Cold Deck Entering Air Flow Low Limit Setpoint
Neutral Deck Entering Air Flow
Neutral Deck Entering Air Flow Setpoint
Neutral Deck Entering Air Flow High Limit Setpoint
Neutral Deck Entering Air Flow Low Limit Setpoint
Return Air Dew Point Temperature
Return Air Dew Point Temperature Setpoint
Terminal Loadswitch:Terminal_Load_Sensor
Cooling Loadswitch:Cooling_Load_Sensor
Heating Loadswitch:Heating_Load_Sensor
Reheat Enable Command | Auxiliary Heating Enable Command
Reheat Enable Status | Auxiliary Heating Enable Status
Reheat Command | Auxiliary Heating Command
Preheat Enable Command
Preheat Enable Status
Preheat Command
Heating Callswitch:Heating_Call_Status
Cooling Callswitch:Cooling_Call_Status
Zone Air TemperatureZone_Air_Temperature_Sensor
Zone Air Temperature SetpointZone_Air_Temperature_Setpoint
Zone Air Temperature Effective SetpointEffective_Zone_Air_Temperature_Setpoint
Zone Air Temperature Effective Cooling Setpointswitch:Cooling_Effective_Zone_Air_Temperature_Setpoint
Zone Air Temperature Effective Heating Setpointswitch:Heating_Effective_Zone_Air_Temperature_Setpoint
Zone Air Temperature Occupied Cooling Setpointswitch:Cooling_Occupied_Zone_Air_Temperature_Setpoint
Zone Air Temperature Occupied Heating Setpointswitch:Zone_Air_Temperature_Occupied_Heating_Setpoint
Zone Air Temperature Unoccupied Cooling Setpointswitch:Zone_Air_Temperature_Unoccupied_Cooling_Setpoint
Zone Air Temperature Unoccupied Heating Setpointswitch:Zone_Air_Temperature_Unoccupied_Heating_Setpoint
Zone Air Temperature Standby Cooling Setpoint
Zone Air Temperature Standby Heating Setpoint
Zone Air HumidityZone_Air_Humidity_Sensor
Zone Air Humidity Setpoint
Zone Air Humidity High Limit Setpoint
Zone Air Humidity Low Limit Setpoint
Zone Air Pressure
Zone Air Pressure Setpoint
Zone Air CO2switch:Zone_Air_CO2_Sensor
Zone Air CO2 Setpointswitch:Zone_Air_CO2_Setpoint
Zone Air COswitch:Zone_Air_CO_Sensor
Zone Air CO Setpoint
Zone Air NO2
Zone Air NO2 Setpoint
Zone Air TVOC
Zone Air Radon
Zone Air Temperature Setpoint Deviation
Outside Air Callswitch:Outside_Air_Call_Request_Status
AHU Statusswitch:AHU_On_Off_Status
AHU Call

Minimum Sets

The minimum selection of points Switch Automation expects to see on an entity of this type.

Base VAV (Minimum Set)

At least one of the following points

switch:hasPointNamesh:class
Run CommandOn_Off_Command
Run StatusOn_Off_Status
Enable CommandEnable_Command
Enable StatusEnable_Status
ModeMode_Status