100299634_2000545244_ Rev. A
33
WATER
HEATER
MODEL
HEATER
INPUT
(BTU/HR)
VENT SIZE (INSIDE
DIAM.)
PRESSURE
SWITCH
SETTINGS
(in. W.C.)
2 PIPE
EQUIV. VENT LENGTH
CONC. VENT
EQUIV. VENT LENGTH
N.C.
N.O.
MAX.
MIN.
MAX.
MIN.
75 gal.
76k
3” (See Figure 43)
-1.5
-1.05
50’ term. elbow
and debris
screen*
7’ plus term. elbow
and restrictive
screen* on both
intake and exhaust
45’ ( plus term.
and debris
screen*
7’ plus
term. and
restrictive
screen* on
exhaust only
4” (See Figure 44)
125’ plus term.
elbow and
debris screen*
50’ plus term.
elbow and debris
screen*
n/a
n/a
* see Figure 37 and Table 4.
Notes:
1. A horizontal vent
must
have a 45° or 90° vent termination elbow to direct the vent pipe downward unless otherwise specified
by local requirements.
2. A vertical vent
must
have a 90° elbow to direct the vent pipe horizontally followed by a vent termination 45° elbow to direct
the vent pipe downward unless otherwise specified by local requirements.
3. If additional elbows are used in the vent system the allowable vent lengths are reduced.
4. Two 45° elbows are considered the equivalent of one 90° elbow.
Table 5.
WATER
HEATER
MODEL
HEATER
INPUT
(BTU/
HR)
VENT
SIZE
(INSIDE
DIAM.)
PRESSURE
SWITCH
SETTINGS
(in. W.C.)
LOW PROFILE
EQUIV. VENT
LENGTH
PYRAMID
EQUIV. VENT LENGTH
MUSHROOM
EQUIV. VENT LENGTH
N.C.
N.O.
MAX.
MIN.
MAX.
MIN.
MAX.
MIN.
75 gal.
76k
3” (See
Figure 43)
-1.5
-1.05
50’ plus
term.
7’ plus
term. and
restrictive
screen*
on both
intake
and
exhaust
50’ plus
term.
7’ plus term.
and restrictive
screen* on
both intake and
exhaust
50’ plus
term.
7’ plus term.
and restrictive
screen* on
both intake
and exhaust
* see Figure 37 and Table 4.
Notes:
1. A horizontal vent
must
have a 45° or 90° vent termination elbow to direct the vent pipe downward unless otherwise specified
by local requirements.
2. A vertical vent
must
have a 90° elbow to direct the vent pipe horizontally followed by a vent termination 45° elbow to direct
the vent pipe downward unless otherwise specified by local requirements.
3. If additional elbows are used in the vent system the allowable vent lengths are reduced.
4. Two 45° elbows are considered the equivalent of one 90° elbow.
Table 6.
