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41
FIG. 40
SINGLE VENT SYSTEM
FIG. 41
MANIFOLD VENT SYSTEM
Venting
1. INSTALL VENT CONNECTOR from canopy
Drafthoodordampertochimneymaintaining6”
clearances from combustible materials.
2. INSTALL VENT SYSTEM – Typical vent systems are
showninFig.40and41.Someofthefactorsaffecting
ventsizingandconstructionaccompanythesegures.
Vent installation shall be in accordance with local
building codes; or the local authority having
jurisdiction; or the National Fuel Gas Code, ANSI
Z223.1/NFPA 54; or the Standard for Chimneys,
Fireplaces, Vents and Solid Fuel Burning Appliances,
ANSI/NFPA 211. Both of the aforementioned
standards, ANSI Z223.1 and ANSI/NFPA 211,
UpperEndPanelusingtwo#10-32x½”MSand
nuts.Mountjunctionboxtobracketusing#8
SMS,seeFigure25or26.InstallTransformeron
junctionbox.
specify Type B and Type L double wall metal vents
andreclaytilelinedmasonrychimneysassuitable
chimney constructions for Category I, draft hood
equipped appliances, such as this Series 5B boiler.
Both standards prohibit the use of unlined masonry
constructionasachimney,withtheexceptionin
ANSI Z223.1/NFPA 54 that “Where permitted by
theauthorityhavingjurisdiction,existingchimneys
shall be permitted to have their use continued when
an appliance is replaced by an appliance of similar
type,inputratingandefciency.”ANSI/NFPA211
prohibits the use of single wall metal vent as a chimney,
while ANSI Z223.1 allows it under very restrictive
conditions.
InCanada,refertoCAN/CSA-B149.1or.2-M86and
local codes for venting.
SOME ITEMS RELATIVE TO CONSTRUCTION
AND SIZING OF VENT SYSTEM
(1) Total Vent Height.
(2) Vent Connector – make Initial Rise as high as
possible.
(3) Length of Lateral – hold to a minimum.
(4) Number of Elbows – hold to a minimum.
(5) UL Listed Vent Cap – assures full vent capacity
and freedom from adverse wind effects.
(6)LocateBoilerasclosetoChimneyaspossible
consistent with necessary clearances, see page 7.
(7) Run Breeching Horizontal and slope upward to
 Chimneymaximumof¼”perft.
(8) Use thimble where Breeching enters masonry
 chimney–keepbreechingushwithinsideofue
liner – do not connect into same leg of chimney
 servinganopenreplace.
(9) Install vent above bottom of Chimney to prevent
blockage – inspect chimney for obstructions
or restrictions and remove – clean chimney if
necessary.
(10)Providecleanoutinchimney.
(11) Slip joint or draw band – facilitates installation and
future servicing when necessary.
(12) Venting of other appliances into same chimney
or into a common vent will affect sizing of the
chimney or common vent.
(13) Correction for altitude – design vent system for sea
level input.
(14) Provide adequate ventilation of Boiler Room, see
page 7 – this cannot be overemphasized.
(15) Never pass any portion of a vent system thru a
circulating air duct or plenum.
(16)Supportoflateralrunssothatventpipedoesnot
sag.
(17) Support of common vent where it passes thru a
ceiling or roof.
(18) Clearances to combustible material – use of
thimbles.
(19) Firestops.