Raypak AVIA 264A Installation And Operation Manual page 16

Horizontal Through-the-Wall Venting
(Category III)
Installation
These installations utilize the heater's internal blower to
vent the combustion products to the outdoors. Combustion
air is taken from inside the room and the vent is installed
horizontally through the wall to the outdoors. Adequate
combustion and ventilation air must be supplied to the
equipment room in accordance with the NFGC (U.S.) or
B149 (Canada).
The total length of the horizontal through-the-wall flue
system should not exceed 75 equivalent ft (22.86 m) in
length. If horizontal run exceeds 75 equivalent ft (22.86
m), an appropriately-sized variable-speed extractor must
be used. Each elbow used is equal to 12 ft (3.6 m) of
straight pipe.
The vent cap is not considered in the overall length of the
venting system.
The vent must be installed to prevent flue gas leakage.
Care must be taken during assembly to ensure that all
joints are sealed properly and are airtight. The vent must
be installed to prevent the potential accumulation of
condensate in the vent pipes. It is recommended that the
vent be insulated. Insulation is required for installations in
cold environments (i.e. below 40°F or 4°C). It is required
that:
The vent must be installed with a condensate drain
located in proximity to the heater as directed by the vent
manufacturer.
The vent must be installed with a slight upward slope of
not less than 1/4 inch per foot of horizontal run to the vent
terminal.
Termination
The vent cap MUST be mounted on the exterior of the
building. The vent cap cannot be installed in a well or
below grade. It must be installed at least 12" (305 mm)
above ground level and above normal snow levels. The
vent terminal must be located NO CLOSER than 12" (305
mm) off the wall.
For factory approved vent termination caps, refer to the
Illustrated Parts List (IPL) section of this manual. See
page 66.
Certified
Model
Vent
No.
Material
264/404 Category III
* Subtract 12 ft (3.6 m) per elbow.
** Schedule 40 in PVC or CPVC.
16
Vent Maximum
Size Vent Length
ft (m) ft (m)*
4 (1.2) 75 (22.86)
Table K. Category III Horizontal Vent & Horizontal Direct Vent
FLUE EXHAUST
VENT CAP
12" MIN
(305 mm)
12" MIN
(305 mm)
CONDENSATION
Figure 10. Horizontal Through-the-Wall Venting
CAUTION: This venting system requires the installation
of a condensate drain in the vent piping per the vent
manufacturer's instructions. Failure to install a condensate
drain in the venting system will cause damage which will
not be covered under warranty.
WARNING: No substitutions of flue pipe or vent
A
cap material are allowed. Such substitutions would
jeopardize the safety and health of inhabitants.
Direct Vent - Horizontal Through-the-Wall
Installation
These installations utilize the heater's internal blower to
draw combustion air from outdoors and vent combustion
products to the outdoors, see Table K.
NOTE: Use of B-vent on such a system does not meet
direct-vent requirements.
The exhaust and intake systems must be installed to
prevent the potential accumulation of condensate. It is
recommended that they be insulated. Insulation is required
for installations in cold environments (i.e. below 40°F (4°C).
The flue termination cap is not considered in the overall
length of the venting system.
Combustion Air Intake
Pipe Material**
Galvanized Steel,
PVC,
ABS,
CPVC
INSULATED EXHAUST
VENTING
HEATER
TRAP
Air Intake Max. Length*
ft (m)
4" Ø
75 (22.86)