Loading ...
Loading ...
Loading ...
I Provision for combustionand ventilation air must be in accordance with Section5.3, Air for Combustionand Ventilation, of
the National Fuel Gas Code, ANSI Z223.1-1atest revision, or applicable provisionsof the local building codes.
WARNING
Be sure to provide enough fresh air for combustion.
Enough air insures proper combustion and assures that
no hazard will develop due to the lack of oxygen.
Youmustprovideforenoughfreshairtoassurepropercombustion.Thefire
in theboilerusesoxygen.It musthaveacontinuoussupply.Theair in a
housecontainsonlyenoughoxygentosupplylhe burnerforashorttime.
Outsideair mustenterthehousetoreplacethatusedbytheburner.Study
followingexamples1and2 todetermineyourfreshair requirements.
EXAMPLE1: BoilerLocatedin UnconfinedSpace
Anunconfinedspaceisdefinedasaspacewhosevolumeis notlessthan
50cubicfeelper1,000Bluperhourofthelotalinputratingofallappliances
installedin thatspace.
Ifyourboilerisinanopenarea(unpartitiouedbasement)in aconventional
house,theairthatleaksthroughthecracksarounddoorsandwindowswill
usuallybeadequatetoprovideair forcombustion.Thedoorsshouldnotfit
tightly.Donotcaulkthecracksaroundthewindows.
Equipmentlocatedinbuildingsofunusuallytightconstructionshallbepro-
videdwith airforcombustion,ventilation,anddilutionol fluegasesusing
themethodsdescribedin example2Borshallbespeciallyengineered.The
authorityhavingjurisdictionmustapprovespeciallyengineeredinstalla-
tions.
EXAMPLE2: BoilerLocatedin ConfinedSpace
/L All Air from Insidethe Building:Theconfinedspaceshallbepro-
videdwithtwopermanentopeningscommunicatingdirectlywithanaddi-
tionalroom(s)of sufficientvolumesothatthecombinedvolumeof all
spacesmeetsthecriteriafor anunconfinedspace.Thetotalinputofall
gas:utilizationequipmentinstalledin thecombinedspaceshallbecon-
sideredin makingthis determination.Eachopeningshallhavea mini-
mumfreeareaofonesquareinchper1,000Btuperhourolthetotalinput
ratingofall gasutilizationequipmentin theconfinedspace,butnotless
that100squareinches.Oneopeningshallbewithin12inchesofthetop
andonewithin12 inchesofthebottomoftheenclosure.Theminimum
dimensionofairopeningsshallnolbelessthan3 inches.
B.AllAirfrom Outdoors:Theconfinedspaceshallcommunicatewiththe
outdoorsinaccordancewithmethods1or 2.Theminimumdimensionof
airopeningsshallnotbelessthan3 in.Whereductsareused,theyshall
beof thesamecross-sectionalareaasthefreeareaoftheopeningsto
whichtheyconnect.
1.Twopermanentopenings,onecommencingwithin 12 inchesof the
top,andonecommencingwithin12inchesoftheboltom,oltheenclo-
sureshallbeprovided.Theopeningsshallcommunicatedirectly,orby
theducts,withtheoutdoorsor spaces(crawlor attic)thaifreelycom-
municatewiththeouldoors.
a)Wheredirectlycommunicatingwiththeoutdoorsor wherecommu-
nicatingtotheoutdoorsthroughverticalducts,eachopeningshag
haveaminimumtreeareaof1sq. in.per4000Btuperhouroftotal
inputratingofall equipmentin theenclosure.(SeeFigure3A.)
b)Wherecommunicatingwiththeoutdoorsthroughhorizontalducts,
eachopeningshal!havea minimumfreeareaof 1sq.in. per2000
Blu perhouroftotalinputratingofall equipmentin theenclosure.
(SeeFigure3B.)
2.Onepermanentopeningcommencingwith12 inchesofthelop ofthe
enclosure,shallbepermittedwheretheequipmenthasclearanceofat
NOTE
If you use a fireplace or a kitchen or bathroom exhaust
fan, you should install an outside air intake. These
devices will rob the boiler and water heater of combus-
tion air.
least1 inchfromthesidesandbackand6 incheslromIhefronlofthe
appliance.TheopeningshalldirectlycommunicatewithIheoutdoors
or shallcommunicatethrougha verticalor horizonlalducttotheoub
doorsor spaces(crawlor attic)thatfreelycommunicatewiththeout-
doors,andshallhaveaminimumfreeareaof:
a) 1sq. inchper3000Btuperhourol theIolalinputofaftequipment
locatedin lheenclosure(SeeFigure4),and
b)Notlessthanthesumoftheareasofallvenlconnectorsinthecon-
finedspace.
Figure 3A - FRESH AIR DUCT CAPACITIES (Btuh) i
Fresh Air
Duct Size
3"x 12"
8" x 8"
8" X 12"
81/2"X 16"
1 Square Inch per 4,000 Btuh
100% Free 75% Free
Area Area
1/4"Wire Metal
Mesh Louvers
144,000 108,000
256,000 192,000
384,000 288,000
512,000 384,000
25% Free
Area
Wood
Louvers
36,000
64,000
96,000
128.000
I 3B - FRESH AIR DUCT CAPACITIES (Btuh) I
Figure
1 Square Inch per2,000 Btuh
Fresh Air
Duct Size
3" x 12"
! 8" x 8"
8"x 12"
81/2"x 16"
100% Free 75% Free
Area Area
V4"Wire Metal
Mesh Louvers
72,000 54,000
128,000 96,000
192,000 144,000
256,000 192,000
25% Free
Area
Wood
Louvers
18,000
32,000
48,000
64,000
I FRESH AIR DUCT CAPACITIES (Btuh) i
I
Figure
4
1 Square Inch per 3,000 Bruh
100% Free 75% Free 25% Free
Area Area Area
Fresh Air V,ยข'Wire Metal Wood
Duct Size Mesh Louvers Louvers
3" x 12" 108,000 81,000 27,000
8" x 8" 192,000 144,000 48,000
8" x 12" 288,000 216,000 72,000
8V2"x 18" 384,000 288,000 96,000
5
Loading ...
Loading ...
Loading ...