Ben Burgoyne, ACP, LEED® APMechanical EngineerEbert & Baumann Consulting Engineers, Inc.

Operation Diagnostics as a Form of Trend Data Analysis

AIA Quality Assurance

The Building Commissioning Association is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Course Description

One of the core objectives of the commissioning process is to ensure that a building’s dynamic systems function correctly. Just as important, if not more so, is enabling the correct function of those systems throughout occupancy. With analysis of trend data through visualization (including graphs, charts, etc.), a quick and accurate diagnosis of incorrect or less than optimal operation can be assessed. This presentation describes a method of building system trend data analysis, known as Operation Diagnostics, that involves the creation of ideal patterns for comparison to actual building data visualizations.

At the end of this session, participants will be able to:

1. determine that trend data needs to be deemed reliable and accurate; location of what you’re sensing and how it is being sensed is as important as the value itself.

2. determine, through the presented trend data analysis principles, what data it is valuable to trend.

3. through the presented trend data analysis principles, more effectively visualize and interpret trend data.

4. through the presented trend data analysis principles, communicate results effectively with the client, construction team, and/or facilities management.

Learning Objectives

Operation DiagnosticsOperation

Diagnostics-Trend data analysis through visualization

• BAS Data Visualization

• Interoperability Matrices

• Operation Patterns

• Operation Schematics

• Fault Analysis

BAS Data Visualization

Scatter Plot Matrix

• Shows dependencies between trend data points. • Brushing function allows selected “points” to be highlighted in all scatter plots

within the matrix.

p

…are automatically brushed at the same instances on all other plots.

Zone Temperature

Zone TemperatureSet Point

Zone Mode

Zone

Te

mpe

ratu

reZo

ne T

empe

ratu

reSe

t Poi

ntZo

ne M

ode

Data brushed green, red, and blue on one plot…

Interoperability MatricesExplicit Correlation:

Room Temperature vs.

VAV Flow Set Point

Room TempRoom Temp Set Point X

VAV FlowVAV Flow Set Point X X X

VAV Heating Coil Valve X X XOutdoor Air Temp O

Duct Static Pressure XDuct Static Pressure Set Point X

Supply Fan Power X XSupply Air Temp

Supply Air Temp Set Point X X OAHU Heating Coil Valve O O X XAHU Cooling Coil Valve I O X X X

AHU Outdoor Air % X X X X X

x

O

I

AH

U C

oolin

g C

oil V

alve

AH

U O

utdo

or A

ir %

Correlation is directly described in the sequence of operations.

Correlation is not directly specified, but is relevant.

Additional / Optional dependencies

Duc

t Sta

tic P

ress

ure

Duc

t Sta

tic P

ress

ure

Set

Poi

nt

Sup

ply

Fan

Pow

er

Sup

ply

Air

Tem

p

Sup

ply

Air

Tem

p S

et P

oint

AH

U H

eatin

g C

oil V

alve

Roo

m T

emp

Roo

m T

emp

Set

Poi

nt

VA

V F

low

VA

V F

low

Set

Poi

nt

VA

V H

eatin

g C

oil V

alve

Out

door

Air

Tem

p

System Interoperability Matrix – VAV AHU

• The control points are listed on both axes,

• Correlations are marked based on the level of dependency.

x

Implicit Correlation:Cooling Coil Valve

vs. Supply Fan Power

O

Additional Correlation:Cooling Coil Valve

vs. Heating Coil Valve

I

Operation Patterns 

OA Damper at minimum position

OA Damper returns to minimum position below the low limit disable.

OA Damper fluctuates from minimum to 100% (economizer

mode enable)

OA Damper at 0% (AHU is off or on night setback).

Sample Operation Pattern–Air-Side Economizer Operation based on Outdoor Air Enthalpy

• Interaction between two or more variables in ideal operation.• Identified in the Interoperability Matrix• When visualization is overlaid, shows where operation deviates from ideal.

Operation Schematics

HW System

CHW SystemAHU-4RF-4 Admin Area

EF-1

VAV-1 thru -7

Outdoor Conditions

System Flow Schematic –VAV AHU System with CHW Cooling, Hot Water Heating, and VAV Reheat

Dependent components are connected that signify energy conveyance.

Operation Schematics

HW System

CHW SystemAHU-4RF-4 Admin Area

EF-1

VAV-1 thru -7

Outdoor Conditions

System Flow Schematic –VAV AHU System with CHW Cooling, Hot Water Heating, and VAV Reheat

Dependent components are connected that signify energy conveyance.

Operation SchematicsOperation Schematic

• Shows the interrelationship among all applicable Operation Patterns in a system.

• Aids in tracking faults to their source and in identifying optimization potential.

Operation SchematicsOperation Schematic

• Shows the interrelationship among all applicable Operation Patterns in a system.

• Aids in tracking faults to their source and in identifying optimization potential.

Operation SchematicsOperation Schematic

• Shows the interrelationship among all applicable Operation Patterns in a system.

• Aids in tracking faults to their source and in identifying optimization potential.

Fault Analysis

Fault AnalysisStep 1

• The trend data is visualized.

Step 2

• The Operation Pattern is compared to the BAS visualization.

Step 3

• Faults are detected and marked.

Step 4

• Fault instances deemed invalid are filtered out.

• Here the remaining faulty operation is room temperature too far below set point.

Fault Analysis

Fault AnalysisStep 5

• Using the flow of the Operation Schematic, possible sources of the fault instance are ruled out.

• Shows that the source of the fault might lie along another path.

• Here, the air flow maintains set point during the fault period, indicating the fault lies down another path.

Fault Analysis

Fault AnalysisStep 6

• The true source of the fault instance is ascertained

• The fault instance corresponds with a fault instance in another Operation Pattern along the path.

• In this case, the steam valves did not open, causing the hot water temperature to fall below set point, correspondent with the original fault- room temperature below set point.

Scatter Plot Matrix

Focus of fault analysis

Zone

Te

mpe

ratu

reZo

ne

Tem

p SP

VA

V B

ox

Val

ve P

os.

AH

U

Mod

eH

X V

alve

Po

sitio

nH

W P

ump

Out

put

HW

Tem

p –

Set P

oint

Zone Temp SP

Zone Temperature

VAV Box Valve Pos.

AHU Mode

HX Valve Position

HW Pump Output

HW Temp –Set Point

Source of fault

Corresponding time frame

Enhanced Building and System OperationConclusions

• Building system operation can be effectively evaluated through trend datavisualization methodology.

• Operation Diagnostics provides a clear, comprehensive, and systematicapproach to trend data visualization and analysis through:

• BAS Data Visualization (Scatter Plot Matrices)• Interoperability Matrices• Operation Patterns• Operation Schematics• Fault Analysis

Ben Burgoyne, ACP, LEED® AP

Tel +1.202.608.1334 Fax +1.202.544.1434 b.burgoyne@eb-engineers.com www.eb-engineers.com