AHU Operational Control Spreadsheet Training Doc

8/11/2019 AHU Operational Control Spreadsheet Training Doc

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1

HVAC Special Working Group

Spin III

Web v.1


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Section Title

Air Handling Unit

Operational Control

Spreadsheet Training


3/17

Objectives

3

To provide a tool for systematic review of AHU performance

Paper based or Excel spreadsheet based

For use by operations and maintenance personnel

Applies logical checks

Illogical outcomes highlighted for investigation


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Layout

Macro tools

One for RH system, one for heating systems

Determine desired AHU status from temp & RH requirements

Determine room needs from temp & RH requirements

Check sheet

Customise sheet per AHU

Include design operational control parameters

4


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Macro tools

Assessment Tools- allows the

operator to determine the

desired status of the AHU

based on air temp & RH.

(i.e. should the AHU be in

dehum mode based on outsidetemp and RH

Also determines the room

requirements.

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AHU Condition Assessment Tool

Outside Air Temperature-Enter value between

-200Cand 350C

Relative Humidity-Insert

value between 0%and100%

Fresh Air Requirements-Insert valuebetween 0% and 100%

AHU Supply Air Condition-Insert value between 50C

and 250C

AHU Supply Aircondition-Insert

value between 0%and 100%

AHU Conditions Required Red-Heating

Blue-Cooling Green Rehumification

Blue-DehumificationIndicates RoomRequirement

Insert RoomTemperature and

HumiditySpecifications

between 150Cto 250Cand 0% To 100%

AHU Return AirRequirements-

Insert value between50C and 250C

AHU Return AirCondition-Insert

value between 0%and 100%


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Check sheet

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Enter AHU Number Insert Description of AHU

including location andareas served by AHU

Insert Date (Format 03 Mar

10)

Insert Time (24 Hour Clockformat e.g. 16.45)

Insert Room Humidification

Requirement from Macro Tool

DeHumRehum

N/A (when Dehum or Rehum are

not required)

Enter Room

Heating

Requirements-Heating

Cooling

None

Insert AHU HumidificationStatus from Macro Tool

DeHumRehum

N/A (when Dehum or

Rehum are not required)

Enter AHU

Heating Status-

HeatingCooling

None


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AHU Set point Status & ConditionsInsert design supply air temperature and

humidity set points.

Insert the Original Supply Air

Volume and Return Air

Volume set points.

Insert Filter dP

limits.

Insert actual setpoint values

from BMS screen

Insert value for

each of the

conditions fromBMS screen

Insert commissioning

report data.


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AHU Set up CheckDetermine Result from Building

Management System (BMS). Enter

Yes No or N/A. Red colour indicatesincorrect result/problem on system

Determine Result from BMS.When mixing section is fixed

enter N/A.

Determine Results from

BMS. Enter Yes, No or N/A

Determine result from BMS. View

trends for Control Valves, Speed etc

to determine if record is stable.Enter Yes No or N/A

Confirm on BMS

room pressure

operating accordingto specification.

Enter Yes, No or N/

A


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AHU Operating Situation

Enter AHU pre-heating value which

can be obtained from BMS.

Enter AHU pre-cooling value which

can be obtained from BMS.

Enter cooling valve data from

BMS.

Enter heating valve data from

BMS.

Enter pre-dehumidifcation value data

from BMS.

Enter de-humidifcationvalue data from BMS.

Enter heat recovery data from BMS. If heat recovery

fixed record 100% for running and enter 0% if heat

recovery is not running

Enter fresh air and

mixing air data fromBMS.


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AHU ConditionsEnter AHU mode. This has already beendetermined in Macro status Section.

Consult Macro Section when enteringvalue.

Determine if heating and cooling valvesare open at same time.

When heating is required heat recoveryshould be the first stage of heating.

When cooling is required heat recoveryshould be off. Enter yes, No or N/A

Free cooling from outside should be maximized whenavailable, and should be the first stage of cooling.

If outside air is colder than return air then100% fresh airshould be used before chilled water.

Free heating from outside should be maximized when available, andshould be the first stage of heating if outside air is hotter than return air

then in this case 100% fresh air should be used before heat recovery orLPHW.

Determine ifthe rooms

supplied byAHU are within

specification fortemp and RH.

Using the Macro Statusinformation determine if

the AHU is achievingthe conditions required

for each room.

Determine if theheating/Cooling

valves are operatingat 100% If answer is

Yes then a system is

maxed out and mayindicate a problem.


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AHU ConditionsDetermine DeHum mode fromMacro Status for AHU.Determine if the AHU is carrying out

DeHum and Re-Hum at the same time.

One should always be at 0%.

Determine if chilled water Pre-DeHum is

maximized when Dehum is required.

(Pre-DeHum with chilled water is cheaper than

dessicant drying, and therefore the Pre-DeHumshould be 100% before dessicant drying

commences)

Determine if Roomtemperature

conditions are being

met. When in DeHummode or ReHum

mode verify if the

system control thefinal temperature of

the rooms.

See the Macro

Status .Determine ifthe AHU status match

the room status.

Determine if enthalpy

control is being used

Confirm that thepositions of the exhaust

air and mixing dampers

approximately = 100%

Determine if the fan speed is increasing/decreasingover time and determine if this can be explained by

filter conditions

Determine if thestatis pressures is

increasing/

decreasing over timeand determine if this

cat be explained by

the filter conditions.

Determine if the fanpower is increasing/

decreasing over time

and determine if thiscan be explained by

the filter conditions.

Compare the changes in filter

DP with the filter changehistory. Step reductions in DP

should correspond with filter

changes


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Use of check-sheet (Paper)

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Customise worksheet per AHU

Copy insert or delete lines as required

Fill in design data

Fit one or multiple AHU spreadsheets in each page

Print workbook


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Use of check-sheet (excel)

Customise worksheet per AHU

Copy insert or delete lines as required

Fill in design data

Fit one or multiple AHU spreadsheets in each page

Complete the spreadsheet

Insert new column for further data entry as per next slide

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To Copy Cells for Adding Data

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Highlight Column E of

Excel Sheet. Right

Click and select Copy

Right Click and

select Insert

Copied Cells

Delete Contents of

Copied Cell and add

AHU data as required


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Use of check-sheet (excel)

All cells highlighted in red have potential issues causing

excessive energy usage

All issues should be fed into maintenance system on site Spreadsheet can form part of the operational control clause of

the energy management system


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AHU Operational Control

Spreadsheet Training

Documents

AHU Operational Control Spreadsheet Training Doc