Rheem HB Duct Ready Series Use & Care Manual page 13

NOTICE: These
seven questions
should be answered
to ensure correct duct
configuration.
See Ducting Example.
Rigid Adjustable
Elbow
Flex Duct
Insulation Extented
over Rigid Ducting
and secured with
Duct Tie
Rigid Duct
secured with 4
screws to unit
ange
Ducting Example:
Exhaust/Inlet or both? Both, Inlet and Outlet
Ducting to outside of building or another room? Outside building.
Length of duct from water heater to termination? 20 ft.
Flexible or Rigid ducting? Flexible.
Diameter of ducting used? 8 in. Diameter
Diameter of wall penetrations? 5 in. Diameter
Number of elbows/bends? 3 Total – One on inlet and Two on Outlet
I. Does calculated ducting length exceed maximum allowable table?
a. 20 ft. (Outlet duct length)
b. 10 ft. (1 rigid elbow and 1 bend on outlet)
c. 20 ft. (reduced diameter termination outlet)
d. 20 ft. (Inlet duct length)
e. 5 ft. (1 Bend on inlet)
f. 20 ft. (reduced diameter termination inlet)
g. Total = 20+10+20+20+5+20 = 95 ft.
Using flexible 8 in. diameter duct, the maximum duct length allowed is 125
ft.; therefore, because 95 ft. is less than 125 ft., this is an acceptable ducting
configuration.
Accesory Kits SP20887 (2 Kits), SP20889 (2 Kits) and SP20890 (1 Kit) should
be purchased for this installation.
Flex Duct secured and
sealed with Duct tie
(2 places on Inlet)
(1 place on Outlet
to secure Flex Duct to unit ange)
8" Insulated
Flex Duct
6" Clearance
8" to 5"
for lter
Duct Reducers
8" Insulated
Flex Duct
Flex Duct Insulation
extended over reducers
and secured with Duct tie
Horizontal Duct
Installation
Once the duct terminal
location has been
determined, make a hole
through the exterior wall
to accommodate the UL
Certified Termination.
Termination must exit
Air Inlet
exterior wall horizontally
only.
Complete rest of the
UL Certi ed
terminations duct pipe installation to
the water heater's duct
connector fitting.
If necessary, support
horizontal run as
Cold
previously mentioned.
Air Exhaust
HVAC tape used
to seal Reducer
and termination joints
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