© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Optimization

The Trane Company

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan PressureControl Methods

Fan outlet static pressure

Supply duct static pressure

Fan pressure optimization

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control

StaticPressure

(in. wg)

2.70

1000 rpm

A

SystemResistanceAt DesignConditions

24

Airflow (1000 cfm)

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsFan Outlet Static Pressure

Pressure Control Loop

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsFan Outlet Static Pressure

StaticPressure

(in. wg)

SPC=1.40

1000 rpm,IGV 100%Open System

ResistanceAt Design

Airflow (1000 cfm)

SystemResistance

At Part Load

1000 rpm,IGV PartiallyOpen

Fan ModulationCurve

2418

13 bhp

C

A

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsSupply Duct Static Pressure

Pressure Control Loop

Approximately2/3 Down Duct

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsSupply Duct Static Pressure

© American Standard Inc. 1996 © American Standard Inc. 1996

SystemResistance

At Part Load

A

SystemResistanceAt Design

Airflow (1000 cfm)

2418

StaticPressure

(in. wg)

SPC=0.80

Fan ModulationCurve

1000 rpm,IGV Partially

Open

1000 rpm,IGV 100%Open

D

12 bhp

© American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsFan Pressure Optimization

Communicating BAS

Fan SpeedOr Inlet Vane Position

Duct Pressure Sensor

DamperPositions

DamperPositions

© American Standard Inc. 1996 © American Standard Inc. 1996 © American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsFan Pressure Optimization

A

SystemResistanceCurve

Airflow (1000 cfm)

2418

StaticPressure

(in. wg)

1000 rpm,IGV Partially

Open

1000 rpm,IGV 100% Open

E 9.5 bhp

© American Standard Inc. 1996 © American Standard Inc. 1996 © American Standard Inc. 1996 © American Standard Inc. 1996

Fan Pressure Control MethodsFan Optimization Control Logic

© American Standard Inc. 1996 © American Standard Inc. 1996

Total Building HVAC EnergyFan Control Method Comparison

Miami Mpls. Seattle Toronto93

94

95

96

97

98

99

100

Miami Mpls. Seattle Toronto

Fan Outlet Control

Duct Static Pressure

Fan Pressure Optimization

% H

VA

C E

ner

gy

Co

nsu

mp

tio

n

Analysis performed with TRACE® 600 building energy andeconomic analysis software.

© American Standard Inc. 1996 © American Standard Inc. 1996

Ventilation Reset AndFan Pressure Optimization

Flow Control AtASHRAE OA

Ventilation ResetWith PressureOptimization

Miami Mpls. Seattle Toronto50

60

70

80

90

100

Flow Control WithPressure Optimization

% H

VA

C E

ner

gy

Co

nsu

mp

tio

n

Analysis performed with TRACE® 600 building energy andeconomic analysis software.

© American Standard Inc. 1996 © American Standard Inc. 1996

Ventilation Reset With Pressure OptimizationSystem Requirements

VAV terminals with DDC controls

Air handler with controls

Ability of measure and modulate OA

Method of supply fan control

Building Automation System capable of solving ASHRAE 62-89 Equation 6.1

© American Standard Inc. 1996 © American Standard Inc. 1996

All zones properly ventilated atall loads

No zones are starved for air

Substantially reduced “system” operating costs

Nonproprietary system components

Faster system start-up and installation due to factory-installed and commissioned controls

Ventilation Reset With Pressure OptimizationYields …