Reznor UDBS Option - Installation - Separated Combustion Venting - Manual (Page 6)

Form I-UD-V-SC, PN195676R17, Page 6
Applies to: Residential or Commercial/Industrial Installation
NOTE: Only UDAS 30, 45, 60, 75, 100, and 125 are certified for residential use.
1.0 Venting and Combustion Air Requirements (cont’d)
1.7 Condensation On units with long vent runs (over 50% of maximum vent length allowed) or
installed in low ambient conditions (below 50°F), it is recommended that vent
pipes be fitted with a tee, a drip leg, and a clean out cap to prevent any mois-
ture in the vent pipe from entering the unit. The drip leg should be inspected and
cleaned out periodically during the heating season.
On all Model Sizes, 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 50°F or less,
must be insulated along its entire length with a minimum of 1/2” foil-faced fiber-
glass, 1-1/2# density insulation.
On horizontal vent runs, the flue pipe
must be pitched down toward the outlet 1/4”
per foot for condensate drainage. Slope applies to entire length of horizontal vent run.
Failure to pitch vent run properly may damage unit due to condensate running back
into the unit.
1.8 Concentric
Adapter Box
FIGURE 4 - A
Concentric Adapter
Box is a Required
Part of all Model
UDAS and UDBS
Installations
View of
Heater
Connection
Side
Collar for attaching outside
concentric portion of the
combustion air pipe
Collar for connecting indoor
portion of the combustion air
pipe
Opening for exhaust vent
pipe to pass through the box
(See NOTE in FIGURE 6.)
View
of Vent
Terminal
Connection
Side
CAUTION:
Exceeding the
specified vent
pipe diameter and
length may result
in condensate
forming in the vent
pipe.
End View
showing airflow Gray Arrows
show Flow of
Combustion Air
Vent (exhaust gas) flows through
the field-supplied vent pipe
that extends straight through
the concentric adapter box.
(Collar for attaching indoor
combustion air pipe)
(Collar for attaching outdoor
combustion air pipe)
FIGURE 5 -
Concentric Adapter
Box Airflow
All UDAS and UDBS installations require a concentric adapter box designed to allow
both combustion air and venting with only one building penetration. The concentric
adapter box is included in the vent/combustion air terminal kit. Components and
instructions depend on whether the vent terminal is horizontal (Option CC6) or vertical
(Option CC2).
The illustrations below apply to the concentric adapter box in both the horizontal termi-
nal vent/combustion air kit (Option CC6) and the vertical terminal vent/combustion air
kit (Option CC2). All dimensions are the same except for the opening for the vent pipe
(See NOTE in FIGURE 6).
NOTE: A Model UDAS or UDBS 30, 45, 60, or 75 with a horizontal vent may use
Option CC14 instead of Option CC6. Option CC14 is a more aesthetic concentric vent
terminal/combustion air kit that terminates flush with the wall. If installing Option CC14,
follow the instructions in the option package (Form I-UDAS/UDBS/UEAS-ASC).