function variable air volume (vav)

7/29/2019 FUNCTION VARIABLE AIR VOLUME (VAV)

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Sharingour

Guidance

WHYVARIABLEAIRVOLUME(VAV)?


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WHYVARIABLE

AIR

VOLUME?

INTRODUCTION

Developersareshowingincreasinginterestincentral

airconditioningformanyreasons,themostcommon

ofwhichare:

Challenges

of

vertical

and

high

density

construction

MoreeffectiveManagementcontrolofproperty

Energyconscioussociety

Rooftopcondensingunitfarms become

maintenancenightmares

Useof

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.

ForfullTermsofUseseewww.tesengineering.com/termsofuse.html

2008TESEngineering


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X

VARIABLEAIRVOLUME

BOXCARVAV

Useof

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


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VARIABLEAIRVOLUME

WHYVAV?

Lowerinstalledsize

Lessenergyused

Greatercomfort

Flexibility

Longevity

Serviceable

Useof

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


5/18

XXXXX

VARIABLEAIRVOLUME

WHYVAV?

Lowerinstalledsize

VAVsizeistypically16%lowerthanindividual

Lessenergyused

Smalleroverallsize

15%savingsbyhavingfanspeedtrackwith

varyingload

Greatercomfort

Easytoprovideseparatecomfortzonefor

storefront(sun),generalsales(customers)

andstockareas(employees)

Dryer

supply

air

resulting

in

lower

indoor

humidity

Nooverpressurizationresultingindoors

beingblownopen

Constant,gentleairmotion

Constant,automaticbalancingtoneed

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


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VARIABLEAIRVOLUME

WHYVAV?

Flexibility

Easytoprovideseparatecomfortzone

forstorefront(sun),generalsales

(customers)andstockareas

(employees)

Easytoreconfigurewhenredemising

Longevity

20+yearlifevs.1015forindividualunits

Redundancy

Multiple,independentairconditioning

pipingcircuits

Heavy

duty

construction

Shaftsandbearingsaresignificantly

heavier

Doublewallairboxconstruction

Heavierdutydampers,dampermotors,

etc.

Serviceable

Remotemonitoredmainunit

Remotemonitoredtenantunits

Unitcomponentsbuiltforaccessibility

andreplaceability Electricalcomponents

Bearings Refrigerationsystems

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


7/18

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VARIABLEAIRVOLUME

ISSUES/TOPICS

TenantLoad

Supplementalunits

Odorproducingtenants

Supplyair

Returnair

Outsideair

VAVTerminal

Box

Layout

Controls

Smokedetection

InstallationRequirements

Comfortcomplaints

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


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VARIABLEAIRVOLUME

ISSUES/TOPICS

TenantLoad

Spacesensibleloaddetermines

CFM

Roofloadhandledattheunitlevel

50%+/ ofrecessedlightfixture

loadisappliedtotheplenum&

handledat

the

unit

level

Outsideairloadhandledatthe

unitlevel

PeopledensityperASHRAE

Safetyfactorsunnecessarydueto

VAVsystemloadshiftingcapability

Doors

shall

not

be

propped

open

Supplementalunits

Onlywhenthetenantsair

conditioningand/orventilation

requirementsexceedtheLandlords

allocation

Formostfoodpreparationareas

Wheretenants

use

results

in

a

peopledensityhigherthantypically

expectedinaretailspace,tenantmay

berequiredtoprovidesupplemental

coolingand/orventilationsystem

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


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VARIABLEAIRVOLUME

ISSUES/TOPICS

Supplyair

55Fduringpeakcoolingseason

Resetscheduleonmoderateload

days

14 connectionsat

approximately20 centersprovided

bythe

Landlord

2000CFMmaximumper

connection

Bottomofductis14 above

finishedfloor

Returnair

Plenum

Demisingwalltransferopenings

Sheetmetalsleeve(s)withexpanded

metalinopeningarefurnishedby

Landlord,installedbytenant

Grillelocations

throughout

the

store

&sizedat600FPMmaximum

Transferairductorsoffitacrossspace

ifopenceiling

Nonefromfoodpreparationareas

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


10/18

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VARIABLEAIRVOLUME

ISSUES/TOPICS

Outsideair

Coderequirementsforstreetlevel

retail

Demandcontrolventilationatthe

unit

Tenantmaydeclarethemselvesa

criticalzone

(as

defined

by

ASHRAE)andincludeaspaceCO2

sensor

Makeupairforodorexhaustisnot

availablefromtheLandlordsystem

Freecoolingairsideeconomizer

Economizerrelief

is

in

Landlord

unit

VAVTerminalBox

Fanpoweredwhenheatisprovided

Series(SFPVAV)foraircirculation

Shutoff(VAV)foronlysmallspacesor

wherenoheatrequired

Heat

Noheat

in

Landlord

unit

Demandcontrolventilationto

maximizesupplyairtemperature

duringcoldperiods

ElectricheatprovidedbyTenantin

fanpoweredVAVbox

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


11/18

X

VARIABLEAIRVOLUME

ISSUES/TOPICS

Layout

Zonestorefrontasseparatezone

whenpossible

Windows/sundefinesaseparate

zone

Sensorlocation

Notin

the

sun

Notbehindfixtures

Wirelessthermostatsavailablefor

moreflexibleafterinstallation

locating

Controls

Allcomponentsbythesame

manufacturerastheLandlordssystem

ConnecttoLandlordssystem

EmptyconduitfromLandlords

systemtotenantspaceorjunctionbox

intenant

space

with

cable

loop

ConnectionbyLandlordcontractorat

tenantsexpense

Mayincludezonepanelfor

monitoring/controlofmultipleVAV

boxes

Smokedetection

IMCcommonreturnairexceptionwithvav

boxeslessthan2000CFM

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


12/18

X

VARIABLEAIRVOLUME

ISSUES/TOPICS


Externalductinsulation

Linernotasubstitute)

DuctbetweenLandlordmainandbox

Highpressureconstruction,sealclassA

4diameters

of

rigid

straight

duct

ahead

of

box

Noflexibleconnectioninthissectionofduct

VAVBoxLocation

Stockroomorothernonsaleslocation

Accessibilityrequired

Volumedampersforeachsupplyairoutlet


Accessible

Airbalance

Aftercontrolsareinstalledand

connectedtoLandlordsystem

Deficienciesto

be

addressed

immediately

Priortoceilinginstallationwhen

practical

ReportissuedtoLandlordbefore

grandopening

Use

of

the

information

and

data

contained

within

tesengineering.com

and/or

these

pages

is

at

your

sole

risk.


2008TESEngineering


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X

VARIABLEAIRVOLUME

ISSUES/TOPICS

InstallationDetail

Useoftheinformationanddatacontainedwithintesengineering.comand/orthesepagesisatyoursolerisk.


2008TESEngineering


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VARIABLEAIR

VOLUME

ISSUES/TOPICS

Comfortcomplaints

ContactLandlord

Providedate,timeofday,

temperature,humidity,noise,lack

ofairflow,etc.

Landlordwillverify

Supplyair

temperature

Spacetemperature

VAVboxoperation

dowewantthis??



2008TESEngineering


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VARIABLEAIR

VOLUME

TENANTBENEFITS/FLEXIBILITY

VAVboxesallowmorezoningforstorefront(sun),generalsales(customers)andstockareas

(employees)withsignificantlylessthanthecostofseparatetraditionalrooftopunits.

Landlordssystemprovidesredundancy. Landlordsbuiltinredundancyeliminatestheneed

forTenantstopurchasebackupunitstoprovideredundancy.

Landlordtoinstallhigherenergyefficientunitsleadingtolowerlongtermenergyuse.

EnablesLandlordtoachieveLEEDcertificationandgivetheTenantbenefitofLEEDpointsif

Tenantseeks

LEED

certification.

NoRTUroofpenetrationsbyTenant. FewerroofpenetrationsforLandlordscentralized

coolingsystemleadstofewerleaks.

Lowercommonareacostsduetoreducedsecurityrelatedandfutureroofingrelatedissues.



2008TESEngineering


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VARIABLEAIR

VOLUME

TENANTBENEFITS/FLEXIBILITY

NoRTUmaintenanceresponsibilityforTenantsasLandlordwillprovidepreventative

maintenanceaswellasmaintenancecontractforroutinerepairsofLandlordsrooftop

boxcarunits.

TenantsonlyhavemaintenanceresponsibilityfortheirinspaceVAVboxesanddistribution.

Neatersitewithlessclutteredsplitunitsandreducedopportunitiesforvandalism.

LandlordVACsystemwillbemonitoredandcontrolledviaacomputerizedEnergy

ManagementSystem.

Landlordhastheabilitytotroubleshoottenantairconditioning complaints/problems

remotely

Greatercomfort Dryersupplyairresultinginlowerindoorhumidity

Nooverpressurizationresultingindoorsbeingblownopen

Constant,gentleairmotion

Constant,automatic

balancing



2008TESEngineering


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VARIABLEAIR

VOLUME

LANDLORDSHVACCHARGE

$2.50to$4.00/ft/year

ExampleofTenantscostofowningandoperatingstandalonerooftopunit

About$3.10/ft/year Installation($1.30/ft/year 7yearterm)

Equipment

Roofing

Crane

Startup

AnnualMaintenance($0.50/ft/year)

Energy($1.30/ft/yearwith$0.10/kwhelectricity)



2008TESEngineering


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VARIABLEAIR

VOLUME

THANKYOU

QUESTIONS/DISCUSSION?

function variable air volume (vav)

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