Reznor CAUA Unit Installation Manual - Manual (Page 10)

Form I-CAUA, P/N 164771 R8, Page 10
3) Pipe Diameter and Length
Pipe diameter and length requirements listed in TABLE 7 are for the indoor sections of
pipe between the heater and the concentric adapter box. The diameters of the outside
(terminal) concentric pipes are listed in TABLE 8. The outdoor lengths depend on the
installation; requirements are listed in the installation instructions for the horizontal and
vertical vent/combustion air kits.
Vent pipe diameters and maximum vent lengths in TABLE 7 apply to both horizon-
tal and vertical vents. Add all straight sections and equivalent lengths for elbows.
The total length of the straight sections and elbows must not exceed the Maximum
Length. Minimum length is 5 ft (1.5M).
Vent and Combustion
Air Pipes Between
the Heater and the
Concentric Adapter
TABLE 7 - Pipe
Diameter and Length
from Heater to
Concentric Adapter Box
• Minimum length between the heater and the concentric adapter box is 5 feet
(1.5M).
Concentric Pipes
TABLE 8 - Diameter of
Outdoor Concentric
Pipes
NOTE: Length is
determined by the
installation.
Provide pipe as specified in Requirement No. 1 and seal joints as follows:
• If using Category III vent pipe run, follow the pipe manufacturer's instructions for
joining and sealing Category III vent pipe sections.
• If using single-wall, 26-gauge or heavier galvanized vent pipe run, secure
slip-fit connections using sheetmetal screws or rivets. Seal all joints with high
temperature aluminum tape or silicone sealant.
• To seal joints in the single-wall combustion air pipe, secure slip-fit connections
using sheetmetal screws or rivets. Seal all joints with aluminum tape or silicone
sealant.
• When joining the terminal section of double-wall vent pipe to the vent cap,
follow the illustrated instructions in FIGURE 4A, page 11.
When joining the terminal section of double-wall vent pipe to a single-wall or
Category III vent pipe run, follow the illustrated instructions in FIGURE 4B, page
11.
When joining two sections of terminal double-wall vent pipe in a vertical vent
installation, follow the pipe manufacturer's instructions for joining pipe sections.
5) Joints and Sealing
6.0 Mechanical
(cont'd)
6.2 Venting and
Combustion Air
(cont'd)
Pipe Diameter and Maximum Pipe Length from Heater to Concentric Adapter
CAUA
Pipe Diameter Maximum
Length
Equivalent Straight Length for a
Vent Pipe Inlet Air Pipe 90° Elbow 45° Elbow
inches mm inches mm feet M feet M feet M
150, 200 5 127 5 127 40 12.2 5 1.5 2.5 0.76
250 5 127 6 152 50 15.2 5 1.5 2.5 0.76
300, 350, 400 6 152 6 127 50 15.2 5 1.5 2.5 0.76
Diameters of Concentric (Outdoor Terminal) Pipes
Size 150 200 250 300 350 400
Inlet Air
Pipe
inches 6 6 8 8 8 8
mm 203 203 203 203 203 203
Vent
Pipe
inches 4 4 5 5 5 5
mm 152 152 152 152 152 152
4) Condensation Any length of single-wall vent pipe exposed to cold air or run through an unheated
area or an area with an ambient temperature of 45°F or less must be insulated along
its entire length with a minimum of 1/2" foil-faced fiberglass, 1-1/2# density insulation.
Where extreme conditions are anticipated, install a means of condensate disposal.