Harman HydroFlex 60 Pellet Boiler - Negative Pressure and Electrical Power Failure

12
3-90-233R24_11/13
NOTE: If outside air is installed, the inlet cover should not
be placed in an area where drifting of snow or ice will build
up, blocking the intake air supply.
Hearth&HomeTechnologiesstronglyrecommendstheuse
ofoutsideairforallpelletboilerapplications.
Per national building codes,consideration mustbe given
tocombustion air supply for all appliances inthe vicinity
ofthepelletboiler.Failuretosupplyadequatecombustion
airforallappliancedemandsmay leadtobackdraftingof
thoseappliances.ConsultwithyourHVACProfessionalto
determinethatallcombustionairrequirementsaremet.
When the appliance is side-wall vented:Theairintakeis
bestlocatedonthesameexteriorwallas,andlowerthan
theexhaustventoutlet.
When the appliance is roof vented:Theairintakeisbest
locatedontheexteriorwallorientedtowardstheprevailing
winddirection,duringtheheatingseason.
TheOutsideAirIntakePipeisinsidetheRearCoverandto
therightofthefeedermotor.Theexpipeismadetoslide
insidetheAirIntakePipe. SeeFig.8.Itshouldbeheldinto
placewithsilicone,foiltape,orahoseclamp.(notsupplied)
Negative Pressure and Electrical Power Failure
Toreducetheprobabilityofback-draftingorburn-backinthe
pelletapplianceduringapowerfailure,theappliancemust
beabletodraftnaturallywithoutexhaustbloweroperation.
Negativepressureinthehousewillresistthisnaturaldraftif
notaccountedforinthepelletapplianceinstallation.
Heatrisesinthehouseandleaksoutatupperlevels.This
airmustbereplacedwithcoldairfromoutdoorswhichows
into lower levels ofthe house. Ventsand chimneys into
basementsandlowerlevelscanbecometheconduitforair
supply and reverse under these conditions.
Theoutsideairsupplywillsupplymostofthedemandsof
thepelletappliancetoresistback-drafting,butconsideration
mustbegiventothetotalhousedemand.Itmaybenecessary
to add additional ventilation to the space in which the pellet
applianceislocated.ConsultwithyourHVACprofessionalto
determinetheventilationdemandsforyourhouse.
Inlet Cover part#
1-10-08542
Installation
Fig. 6
Fig. 7
Outside Air
Pipe Knockout
Feeder Cover
Rear Cover
Side
Cover
Outside Air
Althoughstronglyrecommended,theuseofoutsideairis
optional, except where requiredby local building codes.
Thereisabreak-awayholeoneitherrearpanelwhichmust
beremovedbeforeconnectingtheexpipe.SeeFig.7.The
pipeshould berun outsideand terminate3 feetor more
belowor1footormoretothesideoftheventpipeoutlet.
Neverterminatetheoutsideairabovetheventpipeoutlet.
Themaximumlengthofthispipeis15feet.Inletcoverpart
number1-10-08542shouldbeusedtokeepbirds,rodents
etc.outoftheinletpipe.SeeFig.6.
During a loss of electrical power the hopper lid
must be kept in a closed and latched position.
Opening the lid while the combustion blower is
non-operational will allow smoke into the home and
potential overheating of the hopper and fuel. This
can lead to a re in the hopper.
Fig. 8
Outside Air Inlet Pipe