Burnham FREEDOM - Air for Ventilation

10
VI Air for Ventilation
WARNING
OUTDOOR COMBUSTION AIR MUST BE PIPED TO THE AIR INTAKE. NEVER PIPE
COMBUSTION AIR FROM AREAS CONTAINING CONTAMINATES SUCH AS SWIMMING
POOLS AND LAUNDRY ROOM EXHAUST VENTS. CONTAMINATED COMBUSTION AIR WILL
DAMAGE THE BOILER AND MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR
LOSS OF LIFE.
  Airforcombustionmustalwaysbeobtaineddirectlyfromoutdoors,howeversufcientairforventilationmust
stillbeprovidedintheboilerroom.Airforventilationisrequiredtokeepvariousboilercomponentsfromoverheating
and is alwaysobtainedfromindoors.Toensureanadequateventilationairsupply,performthefollowingsteps:
Step1:Determinewhethertheboileristobeinstalledinaconnedspace-AconnedspaceisdenedbytheNational
FuelGasCodeashavingavolumelessthan50cubicfeetper1000BTU/hrinputofallappliancesinstalledinthat
space.Todeterminewhethertheboilerroomisaconnedspace:
• TotaltheinputofallappliancesintheboilerroominthousandsofBTU/hr.Roundtheresulttothenexthighest
1000BTU/hr.
• Findthevolumeoftheroomincubicfeet.Thevolumeoftheroomincubicfeetis:
 Length(ft)xwidth(ft)xceilingheight(ft)
 Incalculatingthevolumeoftheboilerroom,considerthevolumeofadjoiningspacesonlyifnodoorsare
installedbetweenthem.Ifdoorsareinstalledbetweentheboilerroomandanadjoiningspace,donotconsider
thevolumeoftheadjoiningspace,evenifthedoorisnormallyleftopen.
• DividethevolumeoftheboilerroombytheinputinthousandsofBTU/hr.Iftheresultislessthan50,theboiler
roomisaconnedspace.
Example:
A
FCM120andawaterheateraretobeinstalledinaroommeasuring6ft–3inx7ftwithan8ftceiling.The
waterheaterhasaninputof30000BTU/hr:
TotalinputinthousandsofBTU/hr=(120000BTU/hr+30000BTU/hr)/1000=150MBTU/hr
Volumeofroom=6.25ftx7ftx8ft=350ft
3
350/150=2.33.Since2.33islessthan50,theboilerroomisaconnedspace.
Step2a:Iftheboileristobeplacedinaconnedspace,providetwoopeningsintotheboilerroom,oneneartheoorand
oneneartheceiling.Thetopedgeoftheupperopeningmustbewithin12”oftheceilingandthebottomedgeof
theloweropeningmustbewithin12”oftheoor(Figure6.1).Theminimumopeningdimensionis3inches.
• IftheFCMboileristheonlygas-burningapplianceintheboilerroom,theseopeningsmusteachhavea
minimumfreeareaof100squareinches.
• Ifothergas-burningappliancesareintheboilerroom,sizetheopeningsinaccordancewiththeappliance
manufacturer’sinstructionsortheNationalFuelGasCode.Minimumopeningfreeareais100squareinches
evenifopeningrequirementsforotherappliancesareless.
• Ifthetotalvolumeofboththeboilerroomandtheroomtowhichtheopeningsconnectislessthan50cubic
feetper1000BTU/hroftotalapplianceinput,installapairofidenticalopeningsintoathirdroom.Connect
additionalroomswithopeningsuntilthetotalvolumeofallroomsisatleast50cubicfeetper1000BTU/hrof
input.
• The“freearea”ofanopeningtakesintoaccounttheblockingeffectofmesh,grills,andlouvers.Wherescreens
areused,theymustbenonerthan¼”(4x4)mesh.
Step2b:Iftheboileristobeplacedinanunconnedspacethenaturalinltrationintotheboilerroomwillprovide
adequateairforventilationwithoutadditionalopeningsintoboilerroom.