Part No. 4809-0011 Rev 01-10 EV Attic Inlets Page 6 of 14
NOTE: Out. Temp is based off a Target Temp of 80.0° F
Vent Anticipation = On
Learn Times = Yes
Time before fan starts = 5 s
Time after fan starts = 5 s
Reaction Delay = 5 seconds
Pressure Differential = 0.02
Attic Inlets Installed = Yes
Pressure Ramping = On
Target Press. = 0.04 @ High Temp = 84.0°
Target Press. = 0.10 @ Low Temp = 72.0°
Attic Press. = 0.05 @ Out. Temp = 70.0°
3. Utilizing Vent Anticipation
VentAnticipationisafeatureoftheEvolutioncontrollersthatisusedduringminimumventilation.Duringminimum
ventilation,yourfansareoperatingonatimerthereforethereareperiodsoftimewhiletherearenofansoperating.
Whenyourfansareoff,yourinletsystemsarecompletelyclosed.Whenthefanturnson,ittakesacertainamountof
timefortheinlettoopen.Duringthistime,thebuildingwillseehighstaticpressures.Thisputsextraloadonthefans
andcausesthebuildingtospendmuchofitstimercyclenotgettingthefullbenefitsofitsventilation.Vent
anticipationallowstheusertosetthecontrollertoanticipatethetimercycleandpreparetheinletsystemtogetinto
positionbeforetheventilationcyclebegins.Thesesettingsarelocatedonthe“StaticPressure”screenwhichisshown
below.
IfyouwouldliketoutilizeVentAnticipation,youmustfirstenableitbyturningitto“On”.Youmustthendetermine
whetheryouwantthecontrollerto“LearnTimes”.Thissettingallowsthecontrollertoselectandconstantlyupdate
your“Pre”and“Post”anticipationtimes.Thisisnotrecommendedforpeoplewhoutilizeavariabletimerorthe
optimummode.Ifyouset“LearnTimes”to“No”,theusercanmanuallysetthe“Pre”and“Post”anticipationtimes.It
isafairlyeasyprocessbutyoumustfirstunderstandthedifferencebetween“Pre”and“Post”settings.“Pre”indicates
theamountoftimeinsecondspriortothefanturningonwhenyourinletsystemshouldstartmoving.Everyfanhasa
“start‐up”time.Thisistheamountoftimeittakesforyourfantogofromstarttofullspeed.Thisisyour“Post”time.
Typically,thistimeisunder5seconds.
Tomanuallysetyour“Pre”and“Post”times,firstyoumustdetermineabouthowlong,inseconds,ittakesyourinlet
systemtoopenwhenyourminimumventilationfansturnon.Thenyoumustdeterminethe“start‐up”timeofyour
fan,inseconds.Setyour“Post”timeequaltoyour”start‐up”time.Setyour“Pre”timeequaltothetotaltimeminus
your“start‐up”time.Itisimportanttonotethatifyouadd,orremove,fansfromyourminimumventilationyourtotal
inletruntimewillchangebutyour“Post”timewilltypicallybethesamesoadjustmentswillonlybemadetothe“Pre”
time.The“Pre”timeshouldbealinearrelationshipwiththenumberoffansthatyouareusing.Forexample,ifyou
beginwithtwo36”fansforminimumventilationandittakes10seconds“Pre”timeand4seconds“Post”timeforthe
inlettogetinposition.Thenyouaddtwomore36”fansaweeklater.Youwouldleavethe“Post”timeat4seconds
andadjustthe“Pre”timeto20seconds.