Page 2
2. Vent Pipe and Side Wall Venter
Installation.
In this section, special requirements relating to the
combination of the LD or LJ heater and the Tjernlund
side wall vent system are stated. All normal require-
ments of the LD and LJ heater installation and operation
manual and those in the Tjernlund side-wall vent
systems instructions must also be met. Heater location,
combustion air supply, clearance to combustible materi-
al and all other normal installation requirements remain.
2.1 Construction
When using the Tjernlund side wall vent system
with the LD or LJ heater, the following constraints must
be met in order to assure safe and efficient operation of
the system.
1. The appropriate diameter, type "B", double wall
vent pipe must be used to connect the heater to the
side wall vent blower (see Table 1).
2. The construction of the vent must not exceed ten
(10) feet of straight pipe and a total of three (3)
90° turns.
3. Construction of the vent must meet all national
and local building codes.
2.2 Configuration
There are two basic configurations that are al-
lowable when combining the power venter with an LD
or LJ heater. One is a configuration where the initial
section of vent pipe is run horizontally from the top of
the draft hood (see Figure 1). The other configuration
consists of an initial vertical section of vent pipe (see
Figure 2). Either configuration must meet the following
constraints.
1. The draft hood must be connected directly to the
heater as per the draft hood instructions.
2. The side wall vent blower must be installed at the
point of exit from the structure.
3. The vent hood must be connected directly to the
exhaust vent of the blower.
Figure 1. Vent Configuration With Initial Horizontal
Section of Vent Pipe
NOTE: This illustration shows
an LJ heater with a vent system
composed of a draft hood, an
initial horizontal section, the
maximum of three (3) 90° turns,
and the correct placement of the
side wall vent blower and the
vent hood. The "bell" reducer is
in the correct position for heater
sizes 125, 175, 325, and 400.
On a size 250 heater it will be
placed between the draft hood
and the vent pipe.
Figure 2. Vent Configuration With Initial Vertical
Section of Vent Pipe
vENT
bLOwER
DRaFT
HOOD
NOTE: This illustration shows
an LJ heater with a vent system
composed of a draft hood,
an initial vertical section, the
maximum of three (3) 90° turns,
and the correct placement of the
side wall vent blower and the
vent hood. The "bell" reducer is
in the correct position for heater
sizes 125, 175, 325, and 400.
On a size 250 heater it will be
placed between the draft hood
and the vent pipe.
bELL
REDuCER
vENT
bLOwER
90°
TuRN
(ELbOw)
DRaFT
HOOD
vENT
HOOD
bELL
REDuCER
90°
TuRN
(ELbOw)
vENT
HOOD
ELbOw
MOuNTED
DIRECTLY ON
DRaFT HOOD
