CTH3-SERIES INSTALLATION, OPERATION AND SERVICE MANUAL
32 of 71
8.3 Horizontal Venting
In noncombustible walls only, vent terminal
(P/N 02537801-1P) may be used.
For 4" (10 cm) vents in either combustible or
noncombustible walls, use Tjernlund VH1-4 (P/N
90502100) or equivalent, insulated vent terminal.
Follow the manufacturer's instructions for proper
installation.
For 6" (15 cm) common vents in either combustible or
noncombustible walls, use Tjernlund VH1-6 (P/N
90502101) or equivalent, insulated vent terminal.
Follow the manufacturer's instructions for proper
installation.
8.4 Vertical Venting
For 4" (10 cm), an approved vent cap
(P/N 90502300) must be used.
For 6" (15 cm) common vent, an approved vent cap
(P/N 90502302) must be used.
For common vertical venting of more than two heaters,
See Page 34, Section 8.10.
A vent shall not extend less than 2' (.6m) above the
highest point where it passes through a flat roof of a
building.
8.5 Unvented Operation Tube Termination
Turndown type vent terminal with a screen must be
installed at the exhaust end of the tube. Vent terminal
design shall not incorporate backdraft flap.
FIGURE 20: Tube Termination
8.6 Length Requirements
The maximum vent length allowed is 45' (13.7 m). The
maximum outside air supply duct length allowed is 45'
(13.7 m).
The total vent length, plus outside air duct length and
any extensions to minimum heat exchanger lengths,
cannot exceed 65' (19.8 m).
Vent length should be limited to less than 20' (6 m).
If using extended heater lengths or vent lengths
greater than 20' (6 m), condensation will form in the
vent pipe. Insulation and additional sealing measures
(high temperature silicone at all seams) are required.
Optional heat exchanger beyond minimum lengths are
considered as vent length for length determination.
Subtract 15' (4.6 m) of maximum allowed vent or duct
length per vent elbow if more than two are used.
8.7 Horizontal Ventilation 4" (10 cm) Pipe
4" (10 cm)
Single Wall Pipe
Vent Adapter
Vent Terminal
Combustible or
Non-Combustible Wall
Vent Adapter
18" (46 cm)
Min.
Vent Terminal
4" (10 cm) Single Wall Pipe
Non-Combustible Wall Only
SIDE VIEW
Description Part Number
Vent Terminal (Comb. Wall) 90502100
Vent Terminal 02537801-XX