Laars Pennant PNCH Installation And Operation Instructions Manual - page 9
Pennant
(500-2000)
Page 9
length allowed is 50 feet (15.2m). Three elbows have
been calculated into the 50-foot (15.2m) linear run.
Subtract 10 allowable linear feet (3.0m) for every
additional elbow used (see Table 2). When fewer than
3 elbows are used, the maximum linear pipe length
allowed is still 50 feet (15.2m).
The connection for the intake air pipe is on the
filter box. The Pennant appliances may have venting
and combustion air ducting attached to the top or the
back. They are shipped with the connections at the
top. For attaching either or both pipes to the back, the
mounting flanges are reversible by removing the
mounting screws and orienting the flanges in the
desired position. Replace the screws after positioning
flanges. Run a bead of silicone around the collar and
slide the pipe over the collar. Secure with sheet metal
screws.
In addition to air needed for combustion, air shall
also be supplied for ventilation, including all air
required for comfort and proper working conditions for
personnel. The Pennant loses less than 1 percent of its
input rating to the room, but other heat sources may be
present.
2.2 Venting
2.2.1 Vent Categories
Depending upon desired Pennant venting, it may
be considered a Category I or a Category III appliance.
In general, a vertical vent system will be a Category I
system. However, in rare instances, a Pennant’s
vertical vent system may be considered Category III.
In the U.S., the National Fuel Gas Code (ANSI
Z223.1-Latest Edition), or in Canada the CSA B149.1
(latest edition), defines a Category I vent system, and
includes rules and tables to size these vent systems. If
the Pennant’s vertical vent system does not satisfy the
criteria for Category I venting, it must be vented as a
Category III system.
All Pennant vent systems which discharge
horizontally (without the use of a power venter) are
considered Category III vent systems.
2.2.2 Category I Vent
When vented as a category I appliance, the vent
system must conform to the National Fuel Gas Code
(ANSI Z223.1-Latest Edition) in the U.S., or in
Canada, to CSA B149.1 (latest edition). The vent
system must be sized and installed for a Category I
Fan-Assisted Appliance.
If chimney height is greater than 25 feet, or if
multiple units are vented into the same vertical vent, a
barometric damper must be installed on each
appliance, such that the flue draft does not exceed
(negative) 0.1" w.c.
If using a power venter for any type of Category I
venting, the draft should be set between (negative)
0.01 and 0.10" w.c.
2.2.3 Common Venting Systems
Pennant units are Category I fan-assisted when
vented vertically and adhering to all applicable codes.
Pennant units are not allowed to be vented into a
common horizontal vent system, unless a properly
sized vent fan is used, and the common vent system is
properly designed by the vent fan manufacturer or a
qualified engineer. When common venting Pennant fan-
assisted unit with other appliances through one shared
vertical duct called a “common vent”, special care
must be taken by the installer to ensure safe operation.
In the event that the common vent is blocked, it is
possible, especially for fan-assisted devices, to vent
backwards through non-operating appliances sharing
the vent, allowing combustion products to infiltrate
occupied spaces. If the appliances are allowed to
operate in this condition, serious injury or death
may occur.
WARNING
Operation of appliances with a blocked common
vent may lead to serious injury or death. Safety
devices must be implemented to prevent blocked
common vent operation. If safe operation of all
appliances connected to a common vent cannot be
assured, including prevention of spillage of flue
gasses into living spaces, common venting should
not be applied, and appliances should each be
vented separately.
It is for this reason that, in addition to following
proper vent sizing, construction and safety
requirements from the National Fuel Gas Code, ANSI
Z223.1 or in Canada, from CSA B149.1 as well as all
applicable local codes, it is required that installers
provide some means to prevent operation with a
blocked common vent. It is suggested that a blocked
vent safety system be employed such that if the switch
from one appliance trips due to excessive stack spill
or backpressure indicating a blocked vent condition,
that all appliances attached to the vent be locked out
and prevented from operating. Note that the Pennant is
equipped with a blocked vent safety (pressure) switch,
as shipped. However, this safety switch has only been
designed and tested to be effective in installations
where the Pennant is vented separately and NOT
common vented with other appliances. As an
additional precaution, it is recommended that a Carbon
Monoxide (CO) alarm be installed in all enclosed
TERM
DESCRIPTION
Pipe
Single-wall galvanized steel pipe, 24 gauge
minimum (either insulated or non-insulated)
Joint
Permanent duct tape or aluminum tape
Sealing
Table 4. Required Combustion Air Piping Material.