browse

| Overview

Advanced AHU Controls with VAV Advanced Hybrid AHU is a system-level profile in the 75F system. The profile includes all the advanced control sequences in AHU as configurable options.

The focus shift has been towards larger, more advanced air handling units, as 75F started addressing the mid-market (buildings 50-250k sq.ft.). To address these larger AHUs, various techniques were introduced depending on what exists on the controller.

On built-up AHUs, we used an integrated panel to control the unit.  The built-up AHU is one in which the equipment was often assembled in the field and does not have a factory-mounted unit controller, hence it required custom programming to operate correctly.

Advanced AHU Controls with VAV Advanced Hybrid AHU with configurable advanced control sequences can cut the amount of time required to commission such AHUs to a large extent. The already available IO point in the CCU is an added advantage. With the CCU itself, we can perform the advanced AHU functions without adding additional hardware, but the profile also is provisioned to add up to 2 connect modules for any extra IO that might be needed for the AHU for control or monitoring purposes.

| How it Works

Similar to other system profiles, the VAV Advanced Hybrid AHU v2 is also influenced by the zone loads, where based on the zone load the system equipment would provide heating or cooling for more information refer to VAV Advanced Hybrid AHU. It also is capable of controlling these advanced devices based on the Supply Air Temperature (SAT), and Duct Static Pressure (DSP).

Supported With Upto:

  • 5 Stages of Load-Based Cooling
  • 5 Stages of Load-Based Heating
  • 5 Stages of Load-Based Fan
  • 5 Stages of Supply Air Temperature (SAT)-Based Cooling
  • 5 Stages of Supply Air Temperature (SAT)-Based Heating
  • 5 Stages of Duct Static Pressure (DSP)-Based Fan
  • Humidifier, Dehumidifier, Fan and Occupied enable
  • AHU Fresh Air Fan Run Command

| Wiring

| Configuration

The configuration screen for the VAV Advanced Hybrid AHU v2 is accessed from the System Configuration option, as below.

The configuration screen for the VAV Advanced Hybrid AHU v2 displays, as below.

| Configuration Parameters CM/CCU

Sensor Bus Address Setting Configuration, based on sensors Used
Parameter Purpose Default Value Values in the Drop-Down List
Address 0

When a sensor is used for Temperature, Humidity, Occupancy, CO2 & Pressure sensing

Not Connected

For Temperature:

  • Not Connected
  • Return Air Temperature
  • Mixed Air Temperature
  • Supply Air Temperature 1
  • Supply Air Temperature 2
  • Supply Air Temperature 3

For Humidity:

  • NA (Humidity is based on the selection made for the type of temperature sensor)

For Occupancy:

  • Not Connected
  • Occupancy Sensor 1
  • Occupancy Sensor 2
  • Occupancy Sensor 3

For CO2:

  • Not Connected
  • Return Air CO2
  • Mixed Air CO2

For Pressure:

  • Not Connected
  • Duct Static Pressure Sensor 1_2
  • Duct Static Pressure Sensor 2_2
  • Duct Static Pressure Sensor 3_2
Address 1 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected
Address 2 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected
Address 3 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected

 

Analog Input Configuration, based on the Parameter/sensor 
Parameter Purpose Default Value Values in the Drop-Down List
Analog Input 1 When a type of sensing is enabled at the Analog Input port of the CM Duct Static Pressure 2_2
  • None
  • Voltage Input
  • Building Static Pressure _1
  • Building Static Pressure _2
  • Building Static Pressure _10
  • Cooling Valve Position Feedback
  • Discharge Air Damper Feedback
  • Discharge Airflow Sensor_10
  • Discharge Airflow Sensor_20
  • Supply Air Humidity
  • Discharge Air PM 25
  • Discharge Fan Vfd Feedback
  • Duct Static Pressure Sensor 1_1
  • Duct Static Pressure Sensor 1_2
  • Duct Static Pressure Sensor 1_10
  • Duct Static Pressure Sensor 2_1
  • Duct Static Pressure Sensor 2_2
  • Duct Static Pressure Sensor 2_10
  • Duct Static Pressure Sensor 3_1
  • Duct Static Pressure Sensor 3_2
  • Duct Static Pressure Sensor 3_10
  • Heating Valve Position Feedback
  • Minimum Outside Air Damper Feedback
  • Mixed Air Damper Feedback
  • Outside Air Damper Feedback
  • Outside Airflow Sensor_10
  • Outside Airflow Sensor_20
  • Outside Humidity
  • Mixed Air CO2
  • Return Air CO2
  • Return Air Damper Feedback
  • Return Air Humidity
  • Mixed Air Humidity
  • Current Tx 10
  • Current Tx 20
  • Current Tx 30
  • Current Tx 50
  • Current Tx 60
  • Current Tx 100
  • Current Tx 120
  • Current Tx 150
  • Current Tx 200
  • Exhaust Fan Vfd Feedback
  • Outside Fan Vfd Feedback
  • Return Fan Vfd Feedback
  • Supply Air Humidity 1
  • Supply Air Humidity 2
  • Supply Air Humidity 3
Analog Input 2 When a type of sensing is enabled at the Analog Input port of the CM

Return Air CO2

 

 

 

 

 

 

Thermistor Input Configuration, based on the Parameter/sensor used
Parameter Purpose Default Value Values in the Drop-Down List
Thermistor 1 When a type of sensing is enabled at the Analog Input port of the CM Supply Air Temperature 1
  • None
  • Thermistor Input
  • Chilled Water Inlet Temp
  • Chilled Water Outlet Temp
  • Supply Air Temp
  • Mixed Air Temperature
  • Outside Temperature
  • Return Air Temperature
  • Space Temp
  • Supply Air Temperature 1
  • Supply Air Temperature 2
  • Supply Air Temperature 3
  • Discharge Fan AMStatus
  • Discharge Fan Run Status
  • Discharge Fan Trip Status
  • Exhaust Fan AMStatus
  • Exhaust Fan Run Status
  • Exhaust Fan Trip Status
  • Filter Status 1 NO
  • Filter Status 1 NC
  • Filter Status 2 NO
  • Filter Status 2 NC
  • Fire Alarm Status
  • Fire Damper Status 1
  • Fire Damper Status 2
  • Fire Damper Status 3
  • Fire Damper Status 4
  • Fire Damper Status 5
  • Fire Damper Status 6
  • Fire Damper Status 7
  • Fire Damper Status 8
  • High Differential Pressure Switch
  • Low Differential Pressure Switch
  • Outside Fan Run Status
  • Outside Fan Trip Status
  • Outside Fan AMStatus
  • Return Fan Run Status
  • Return Fan Trip Status
  • Return Fan AMStatus
  • Uv AMStatus
  • Uv Run Status
  • Uv Trip Status
  • Condensate Status NO
  • Condensate Status NC
  • Emergency Shutoff NO
  • Emergency Shutoff NC
Thermistor 2 When a type of sensing is enabled at the Analog Input port of the CM Emergency Shut Off NO

 

Relay Based Outputs
Parameter Purpose Default Value Values in the Drop-Down List
Relay 1

To enable staged conditioning control

SAT Cooling Stage 1
  • Load Cooling Stage 1
  • Load Cooling Stage 2
  • Load Cooling Stage 3
  • Load Cooling Stage 4
  • Load Cooling Stage 5
  • Load Heating Stage 1
  • Load Heating Stage 2
  • Load Heating Stage 3
  • Load Heating Stage 4
  • Load Heating Stage 5
  • Load Fan Stage 1
  • Load Fan Stage 2
  • Load Fan Stage 3
  • Load Fan Stage 4
  • Load Fan Stage 5
  • Load Fan Stage 1
  • Humidifier Enable
  • Dehumidifier Enable
  • Sat Cooling Stage 1
  • Sat Cooling Stage 2
  • Sat Cooling Stage 3
  • Sat Cooling Stage 4
  • Sat Cooling Stage 5
  • Sat Heating Stage 1
  • Sat Heating Stage 2
  • Sat Heating Stage 3
  • Sat Heating Stage 4
  • Sat Heating Stage 5
  • Fan Pressure Stage 1
  • Fan Pressure Stage 2
  • Fan Pressure Stage 3
  • Fan Pressure Stage 4
  • Fan Pressure Stage 5
  • Occupied Enable
  • Fan Enable
  • Ahu Fresh Air Fan Run Command
Relay 2

To enable staged conditioning control

SAT Cooling Stage 2
Relay 3 To enable staged conditioning control Fan Pressure Stage 1
Relay 4 To enable staged conditioning control SAT Heating Stage 1
Relay 5 To enable staged conditioning control SAT Heating Stage 2
Relay 6 To enable staged conditioning control Fan Pressure Stage 2
Relay 7 To enable staged conditioning control Humidifier Enable
Relay 8 To enable staged conditioning control Dehumidifier Enable

 

 

Analog Based Outputs
Parameter Purpose Default Value Values in the Drop-Down List
Analog Out 1

To enable modulating conditioning control

Pressure Based Fan Control
  • Pressure Based Fan Control
  • Sat Based Cooling Control
  • Sat Based Heating Control
  • Load Based Cooling Control
  • Load Based Heating Control
  • Load Based Fan Control
  • CO2 Based Damper Control
  • Composite Signal
Analog Out 2 To enable modulating conditioning control Sat Based Cooling Control 
Analog Out 3 To enable modulating conditioning control Sat Based Heating Control 
Analog Out 4 To enable modulating conditioning control CO2 Based Damper Control

 

For analog-based output configuration, additional parameters need to be configured, as below.

For Pressure based Fan Control:

For SAT based Cooling & Heating Control:

For CO2 based Damper Control:

For Load based Cooling, Heating, & Fan Control:

| Adding a Connect Module

A connect module can be added to the profile when required.

  • Click the Add Connect Module to add a connect module to the profile to provision additional control & monitoring ports to the profile.

The Connect module configuration screen displays, as below.

| Configuration Parameters Connect Module

Sensor Bus Address Setting Configuration, based on sensors Used
Parameter Purpose Default Value Values in the Drop-Down List
Address 0

When a sensor is used for Temperature, Humidity, Occupancy, CO2 & Pressure sensing

Not Connected

For Temperature:

  • Not Connected
  • Return Air Temperature
  • Mixed Air Temperature
  • Supply Air Temperature 1
  • Supply Air Temperature 2
  • Supply Air Temperature 3

For Humidity:

  • NA

For Occupancy:

  • Not Connected
  • Occupancy Sensor 1
  • Occupancy Sensor 2
  • Occupancy Sensor 3

For CO2:

  • Not Connected
  • Return Air CO2
  • Mixed Air CO2

For Pressure:

  • Not Connected
  • Duct Static Pressure Sensor 1_2
  • Duct Static Pressure Sensor 2_2
  • Duct Static Pressure Sensor 3_2
Address 1 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected
Address 2 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected
Address 3 When a sensor is used for Temperature, Humidity, Occupancy, and CO2 sensing Not Connected

 

 

Relay Based Outputs
Parameter Purpose Default Value Values in the Drop-Down List
Relay 1

To enable staged conditioning control

Load Cooling Stage 3
  • Load Cooling Stage 1
  • Load Cooling Stage 2
  • Load Cooling Stage 3
  • Load Cooling Stage 4
  • Load Cooling Stage 5
  • Load Heating Stage 1
  • Load Heating Stage 2
  • Load Heating Stage 3
  • Load Heating Stage 4
  • Load Heating Stage 5
  • Load Fan Stage 1
  • Load Fan Stage 2
  • Load Fan Stage 3
  • Load Fan Stage 4
  • Load Fan Stage 5
  • Load Fan Stage 1
  • Humidifier Enable
  • Dehumidifier Enable
  • Occupied Enable
  • Fan Enable
  • Ahu Fresh Air Fan Run Command
Relay 2

To enable staged conditioning control

Load Heating Stage 3
Relay 3 To enable staged conditioning control Load Fan Stage 3
Relay 4 To enable staged conditioning control Load Cooling Stage 4
Relay 5 To enable staged conditioning control Load Heating Stage 4
Relay 6 To enable staged conditioning control Load Fan Stage 4
Relay 7 To enable staged conditioning control Load Cooling Stage 5
Relay 8 To enable staged conditioning control Load Heating Stage 5

 

Analog Based Outputs
Parameter Purpose Default Value Values in the Drop-Down List
Analog Out 1

To enable modulating conditioning control

Load Based Cooling Control

 

  • Load Based Cooling Control
  • Load Based Heating Control
  • Load Based Fan Control
  • CO2 Based Damper Control
  • Composite Signal
Analog Out 2 To enable modulating conditioning control Load Based Fan Control
Analog Out 3 To enable modulating conditioning control Load Based Heating Control
Analog Out 4 To enable modulating conditioning control Composite Signal

For analog-based output configuration under the connect module, additional parameters need to be configured, as below.

For Load based Cooling, Heating, & Fan Control:

For Composite Signal Control:

For CO2 based Damper Control:

Universal Input Configuration Parameters

Thermistor/ Digital Based Universal Inputs

Parameter

Purpose

Default Value

Values in the drop-down list

Universal-in1

To enable Digital/Analog/Thermistor based input sensing

Supply Air Temperature

  • Not Connected
  • Voltage Input
  • Thermistor Input
  • Building Static Pressure _1
  • Building Static Pressure _2
  • Building Static Pressure _10
  • Chilled Water Inlet Temp
  • Chilled Water Outlet Temp
  • Cooling Valve Position Feedback
  • Discharge Air Damper Feedback
  • Discharge Airflow Sensor_10
  • Discharge Airflow Sensor_20
  • Supply Air Humidity
  • Discharge Air PM 25
  • Discharge Fan Vfd Feedback
  • Duct Static Pressure Sensor 1_1
  • Duct Static Pressure Sensor 1_2
  • Duct Static Pressure Sensor 1_10
  • Duct Static Pressure Sensor 2_1
  • Duct Static Pressure Sensor 2_2
  • Duct Static Pressure Sensor 2_10
  • Duct Static Pressure Sensor 3_1
  • Duct Static Pressure Sensor 3_2
  • Duct Static Pressure Sensor 3_10
  • Heating Valve Position Feedback
  • Minimum Outside Air Damper Feedback
  • Mixed Air Damper Feedback
  • Outside Air Damper Feedback
  • Outside Airflow Sensor_10
  • Outside Airflow Sensor_20
  • Outside Humidity
  • Outside Temperature
  • Return Air CO2
  • Mixed Air CO2
  • Return Air Damper Feedback
  • Return Air Humidity
  • Return Air Temperature
  • Space Temp
  • Mixed Air Humidity
  • Current Tx 10
  • Current Tx 20
  • Current Tx 30
  • Current Tx 50
  • Current Tx 60
  • Current Tx 100
  • Current Tx 120
  • Current Tx 150
  • Current Tx 200
  • Exhaust Fan Vfd Feedback
  • Outside Fan Vfd Feedback
  • Return Fan Vfd Feedback
  • Discharge Fan AMStatus
  • Discharge Fan Run Status
  • Discharge Fan Trip Status
  • Exhaust Fan AMStatus
  • Exhaust Fan Run Status
  • Exhaust Fan Trip Status
  • Supply Air Temp
  • Mixed Air Temperature
  • Filter Status 1 NO
  • Filter Status 1 NC
  • Filter Status 2 NO
  • Filter Status 2 NC
  • Fire Alarm Status
  • Fire Damper Status 1
  • Fire Damper Status 2
  • Fire Damper Status 3
  • Fire Damper Status 4
  • Fire Damper Status 5
  • Fire Damper Status 6
  • Fire Damper Status 7
  • Fire Damper Status 8
  • High Differential Pressure Switch
  • Low Differential Pressure Switch
  • Outside Fan Run Status
  • Outside Fan Trip Status
  • Outside Fan AMStatus
  • Return Fan Run Status
  • Return Fan Trip Status
  • Return Fan AMStatus
  • Uv AMStatus
  • Uv Run Status
  • Uv Trip Status
  • Condensate Status NO
  • Condensate Status NC
  • Supply Air Temperature 1
  • Supply Air Humidity 1
  • Supply Air Temperature 2
  • Supply Air Humidity 2
  • Supply Air Temperature 3
  • Supply Air Humidity 3
  • Emergency Shutoff NO
  • Emergency Shutoff NC

Universal-in2

To enable Digital/Analog/Thermistor based input sensing

Mixed Air Temperature

Universal-in3

To enable Digital/Analog/Thermistor based input sensing

Outside Air Temperature

Universal-in4

To enable Digital/Analog/Thermistor based input sensing

Duct Static Pressure (0-2")

Universal-in5

To enable Digital/Analog/Thermistor based input sensing

Current TX (0-50Amps)

Universal-in6

To enable Digital/Analog/Thermistor based input sensing

Condensate Overflow (N/O)

Universal-in7

To enable Digital/Analog/Thermistor based input sensing

Filter Status (N/O)

Universal-in8

To enable Digital/Analog/Thermistor based input sensing

Generic 1-100KOhm

 

Configure the required parameters under the CM & Connect Module Configurations

  • Click SET to confirm the profile configurations.

The profile configurations are confirmed and saved successfully message displays.

The configured VAV Advanced Hybrid AHU v2 profile can be visualized on the CCU system screen, as below.

| Algorithm & Operation

Zone Load Based Controls:

The table below talks about the algorithm and operation of the VAV Advanced Hybrid AHU v2 profile, when the load-based controls are configured for in the profile.

Control Control Type  Operation
Cooling Load Control Relay Based The cooling control stages are enabled and ramped up as the systemCoolingLoopOutput changes from 0% to 100% depending on the load conditions.
Cooling Load Control Analog Based

The cooling control signal modulates between analogOutXAtMinCooling and analogOutXAtMaxCooling as the systemCoolingLoopOutput changes from 0% to 100% depending on the load conditions.

Heating Load Control Relay Based The Heating control stages are enabled and ramped up as the systemHeatingLoopOutput changes from 0% to 100% depending on the load conditions.
Heating Load Control Analog Based

The Heating control signal modulates between analogOutXAtMinHeating and analogOutXAtMaxheating as the systemHeatingLoopOutput changes from 0% to 100% depending on the load conditions.

Load Fan Control Relay Based The Fan control stages are enabled and ramped up as the system Cooling/Heating Loop Output changes from 0% to 100% depending on the load conditions.
Load Fan Control Analog Based

The Fan control signal modulates between analogOutXAtMinFan and analogOutXAtMaxFan as the system Cooling/Heating Loop Output changes from 0% to 100% depending on the load conditions.

 

Supply Air Temperature (SAT) Based Controls:

The table below talks about the algorithm and operation of the VAV Advanced Hybrid AHU v2 profile, when the Supply Air Temperature controls are configured for in the profile.

Control Control Type  Operation
SAT Cooling Control Relay Based
  • TR algorithm resets the SAT Setpoint on the cooling side based on the tuners configured and the zone requests.
  • The SAT is reset between systemCoolingSATMinimum and systemCoolingSATMaximum
  • The SAT cooling control stages are enabled and ramped up as the SATCoolingLoopOutput (Resultant of SAT Setpoint & measured SAT ) changes from 0% to 100%.
SAT Cooling Control Analog Based
  • TR algorithm resets the SAT Setpoint on the cooling side based on the tuners configured and the zone requests.
  • The SAT is reset between systemCoolingSATMinimum and systemCoolingSATMaximum
  • The SAT cooling control signal modulates between analogOutXAtMinSATCooling and analogOutXAtMaxSATCooling as the SATCoolingLoopOutput changes from 0% to 100%.
SAT Heating Control Relay Based
  • TR algorithm resets the SAT Setpoint on the heating side based on the tuners configured and the zone requests.
  • The SAT is reset between systemHeatingSATMinimum and systemHeatingSATMaximum
  • The SAT cooling control stages are enabled and ramped up as the SATHeatingLoopOutput (Resultant of SAT Setpoint & measured SAT ) changes from 0% to 100%.
SAT Heating Control Analog Based
  • TR algorithm resets the SAT Setpoint on the cooling side based on the tuners configured and the zone requests.
  • The SAT is reset between systemCoolingSATMinimum and systemCoolingSATMaximum
  • The SAT cooling control signal modulates between analogOutXAtMinSATCooling and analogOutXAtMaxSATCooling as the SATCoolingLoopOutput changes from 0% to 100%.

 

Duct Static Pressure (DSP) Based Controls:

The table below talks about the algorithm and operation of the VAV Advanced Hybrid AHU v2 profile, when the duct static-based fan controls are configured for in the profile.

Control Control Type  Operation
Pressure Fan Control Relay Based
  • TR algorithm resets the Static Pressure Setpoint on the cooling side based on the tuners configured and the zone requests.
  • The Static Pressure is reset between Static Pressure Minimum and Static Pressure Maximum
  • The Static Pressure Fan control stages are enabled and ramped up as the StaticPressure LoopOutput (Resultant of Static pressure Setpoint & measured Static Pressure) changes from 0% to 100%
Pressure Fan Control Analog Based
  • The Pressure Fan control signal modulates between analogOutXAtMinStaticPressure and analogOutXAtMaxStaticPressure as the StaticPressure LoopOutput changes from 0% to 100%.

 

Composite Controls:

Control Control Type  Operation
Composite Control Relay Based
  • This allows heating and cooling mapping into a single output for interfacing with pneumatic control systems. In such systems 2-6psi represents a call for heating, 6-8 psi is dead band and 8-12 psi represents a call for cooling.
  • The Composite control signal modulates between analogOutXAtMinHeating and analogOutXAtMaxHeating for Heating and between analogOutXAtMinCooling and analogOutXAtMaxCooling for Coolin, using one loop output .

Example: 

AnalogOut at 2-5 V Heating ( 20% of loop output is maximum heating, 50% loop output is minimum heating)
AnalogOut at 5-7 V No Heating or Cooling
AnalogOut at 7-10 V Heating ( 70% of loop output is minimum cooling, 50% loop output is maximum heating)

 

 

Fan Enable:

Whenever heating or cooling conditioning is in action the Fan enabled relay is turned on.

During unoccupied hours relay will turn on only if there is a call for cooling/heating - this includes economizing action)

Occupied Enable:

This relay will be on whenever the building is scheduled for occupancy or systemStaticPressureLoopOutput > 0.

During unoccupied hours relay will turn on only if there is a call for cooling/heating - this includes economizing action)

Humidifier:

The humidifier is turned on whenever the humidity level for the system drops below the targetMinInsideHumidty set on the systems page.

The humidifier will be turned off after being turned on when the humidity goes humidityHysteresis above the targetMinInsideHumidty.

Humidity control will not be maintained during UNOCCUPIED or VACATION modes. Even during pre-conditioning, emergency conditioning, and auto-forced occupied, the humidifier is not operational.

| Post Configuration

The zone paired with VAV Advanced Hybrid AHU is displayed in the CCU as below:

Screenshot 2024-06-12 161616.png

Screenshot 2024-06-12 161234.png

You can see widgets configured in the heatmap pages in the portals as below:

Screenshot 2024-06-12 155438.png

 

Screenshot 2024-06-12 160620.png

 

Screenshot 2024-06-12 160712.png

| Equip Graphics

Equipment graphics is available for all the terminal profiles. It provides a graphical representation of system-level equipment and enables monitoring of key point parameters associated with terminal profiles.

Screenshot 2024-06-17 121209.png

 

The highlighted list of points is predefined for visualization alongside the graphic for the respective profile.

| Feature Availability Versions

Feature Hardware/Firmware Version

The VAV Advanced Hybrid AHU V2 system support

CM 3.53 and above.

The VAV Advanced Hybrid AHU V2 system support

Connect Module 1.4 and above
Previous
Next

Comments

0 comments

Please sign in to leave a comment.

Was this article helpful?

0 out of 0 found this helpful
Powered by Zendesk