4.4Freecoolingdescription
Thisfunctionisusedduringthewarmperiodtosaveenergybyusingcoldoutdoorair,e.g.duringnight
time,tocooldownthebuilding.
Note:
ThefollowingisonlyvalidifthefreecoolingfunctionissettoActiveintheprogrammenu.
Freecoolingisonlyactivatedwhenthefollowingstartingconditionsaremet.
Startingconditions:
•Lessthan4dayshavepassedsincetheunitwaslastinrunningmode
•Theoutdoortemperatureduringthepreviousrunningperiodexceededasetlimit(+22°C)
•Itisbetween00:00and07:00:00intheday(settable)
•Thetimeroutputsfornormalspeed,ExtendedrunningnormalandExternalstopareOff
•AtimechannelwillbeOnsometimeduringtherecentlystarted24hours.
Theunitchecksthenighttemperature(indoorandoutdoortemperature)during3minutesattheset
startinghourwhenthefansarestartedsothatthesensorscanperformatemperaturemeasurement.If
aboveconditionsaremetthefreecoolingfunctionisstarted,ifnottheunitgoesbacktoOFFposition.
Iftheoutdoorsensorisnotlocatedintheoutdoorairinletductandaroomsensorhasbeenselected,
theunitwillnotstartfreecoolingaslongasallthetemperaturesarenotwithinthestartandstop
temperatureintervals.
Stopconditions:
•Outdoortempabovethesetmaxvalue(+18°C)orbelowthesetminvalue(condensationrisk,+10°C)
•Theroomtemp/extractairtempisbelowthesetstopvalue(+18°C)
•Oneofthetimeroutputsfornormalspeed,ExternalstoporExtendedrunningnormalisOn
•Thetimehaspast07:00:00.
Whenfreecoolingisactive,thefansrunatnormalspeedorthesetvalueforpressure/owcontroland
thedigitaloutputFreecoolingisactive.TheoutputsY1-Heating,Y2-Heatexchangerand
Y3-Coolingareshutdown.Afterfreecoolinghasbeenactivated,theheatingoutputisblockedfor60
minutes(congurabletime).
TopvexSR09,11,TR09-15OperationandMaintenanceInstructions
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SystemairAB