Conventional Combustion Air Supply - Raypak XTherm Series Installation & Operating Instructions Manual

B149 (Canada), and all local codes.
Air Filter
Fig. 9: Air Filter
An air filter is supplied standard with the heater.
Direct Vent/TruSeal
Combustion air may be ducted directly to the heater
using PVC, CPVC or sealed single-wall galvanized
ducting. The resulting installation meets the requie-
ments for a direct-vent installation.
CAUTION: Use TruSeal combustion air if damaging
airborne contaminants are or may be present in
the heater area. See the Appendix of this manual
regarding air contamination.
Fig. 10: D-22
1. Install the Air Intake Assembly (sales order option
D-22) over the combustion air intake port on the
back of the unit. See Fig. 10. Three intake ports
are available: left side, right side and rear. Install
the air intake collar on the selected port, and use
®
the supplied covers to seal the other two ports. Air
filter is accessed for inspection or replacement by
removing other side panel (unused side).
2. Install combustion air duct to the Air Intake
Assembly, as illustrated in Fig. 38 (horizontal duct)
or Fig. 39 (vertical duct) of this manual. Seal the
joint and fasteners with RTV (not supplied). All
ducting shall be self-supporting.
3. In cold climates, and to mitigate potential freeze-
up, Raypak highly recommends the installation
of a motorized sealed damper to prevent the
circulation of cold air through the heater during
non-operating hours.
4. Ventilation of the room occupied by the heater(s)
is required and can be provided by an opening(s)
for ventilation air within 12" of the highest practical
point communicating with the outdoors. The total
cross-sectional area of these openings shall be
at least 1 square inch free air space per 20,000
BTUH (111 mm
all equipment in the room, when the opening
is communicating directly with the outdoors or
through vertical duct(s). The total cross-sectional
area shall be at least 1 square inch of net free air
space per 10,000 BTUH (222 mm
input rating of all equipment in the room, when
the opening is communicating with the outdoors
throughhorizontal duct(s). Damage to the equip-
ment due to inadequate ventilation of the space is
not a warrantable failure.
Motorized Combustion Air Dampers or
Louvers
When motorized dampers or louvers are used for
combustion air, they must be interlocked with each
appliance in the equipment room, to ensure proper
operation. See Field Wiring Connection section of
this manual for proper wiring instructions, using Fan/
CAUTION: All ducting should be self-supported.
Damper dry contacts and external interlock.
Conventional Combustion Air
Supply
U.S. Installations
All Air from Inside the Building
The confined space shall be provided with TWO
per-manent openings communicating directly with
12
per kW) of total input rating of
2
per kW) of total
2