Venting - Weil-McLain CGi Series 3 Installation And Maintenance Manual

CG i
GAS-FIRED wATER BOILER- sERIEs a -
Boiler Manual
14
3a
3b
Table 3
Vent
connector
diameter
Figure 7
Chimney
draft
venting
Venting - general information
CGi venting methods - Chimney draft or Direct exhaust
Chimney draft venting
Chimney d raft venting uses the natural draft p rovided
by a vertical vent o r chimney. Category I appliance (no n-
positive vent static pressure and vent gas
temperature
that avoids excessive condensate production
tn
ven t).
See Section 3b. C himney draft installations use:
Direct exhaust - vertical or sidewall
Direct exhaust venting uses inside combustion air with
no combustio n air connector piping. All CGi flue gas
vents are pressurized, requiring careful
sealin~
of all
joints. Category Ill appliance (positive vent static pres-
sure and vent gas teml?erature that avoids excessive
condensate
production m vent). See
pages 15-19.
1. Vent connecto r (single or d ouble wall) sized to
eliminate positive pressure in vent system. Diameter
increases immediately at boiler.
Direct exhaust installations use:
1. V ent pipe specified in this manual
2. Double wall metal vent (B-vent) or chinmey with
liner approved by the National Fuel
Gas
Code, ANSI
Z223.1-latest edition, o rin CanadaBI49.1 o r Bl49.2
Installation Cod e.
2. V ent termination through outside wall, roof or
tm-
used chimney. Tigh t chimney areas will make vent
joint constructio n very difficult.
Venting - chimney draft venting
Boiler ''0'
1
Minimum
model
vent connector
number
diameter
CG;-25 & CGi-3
4"
CGi-4 to CGi-8 5"
Il-l. -- -
Chimney
I&WARNING l
Inspect existing chim ney before installing boiler. Failure to
clean
or rel?lace perforated pipe o r lining will cause severe
personal inJury o r death.
V ent sizing given in Table 3 is only a general guideline. The
vent connector and chimney m ust be designed, sized and
constructed in compliance with all applicable codes. Failure to
correctly
siu
and install the vent system could result in severe
personal injury, death o r substantial p roperty damage.
1. Use do uble
wall
metal vent (B-vent) or chimney with liner as
required by the National Fuel Gas Code, ANSI Z223.1-latest
edition, or in Canada, B149.1 or B149.2 Installatio n Code.
2. To prevent downdrafts, chimney should extend at least 3 feet
above the highest po int where it passes through a roof and
at least 2 feet higher than any portion of a building within
a horizontal distance of I 0 feet.
3. To vent with another appliance, see Natio nal Fuel Gas Code,
ANSI Z223.1-latest edition o r in Canada B149.2 or B149.2
Installation Code
4. Do not connect breeching to any portion of a mechanical
draft system that can operate under positive pressure.
5. Maintain minimwn 2" clearance from combustible materials
to vent pipe.
6. Do not use chimney with an open fireplace.
7.
Make horizontal runs as short as possible. Long runs can
cause condensation.
8. When longer runs are used, support pipe with appropriate
hangers.
9. To prevent blockage, do not vent into bo ttom of chimney.
10. V ent pipe must not go beyond inside wall of chimney.
11. Vent passing through floors o r ceilings must be
firesto pped.
12. See Figure
7
and Table
3
to connect boiler to venting sys-
tem.
Part Number 550-142-780/0712