Service manual

CTH2-SERIES INSTALLATION, OPERATION AND SERVICE MANUAL
32
SECTION 8: VENTING
8.1 Venting
This heater must be vented in accordance with the
rules contained in this manual and with the following
national codes and any state, provincial or local
codes which may apply: United States: Refer to
ANSI Z223.1 (NFPA 54) - latest revision; Canada:
Refer to CAN/CGA-B149.1 and B149.2 - latest
revision.
Exhaust end of heater will accept a 4” (10 cm) vent
pipe using the vent adapter (P/N 90502700). To
prevent leakage of condensation, install the vent
adapter with the seam on top and seal the joint using
a high temperature silicone sealant.
Any portion of vent pipe passing through a
combustible wall must have an approved thimble
(P/N 90505600) to conform with the above listed
codes.
Vent pipe must be sloped downward away from the
burner 1/2” (1 cm) for every 20' (6 m).
The heater may be individually vented or common
vented. When venting horizontally, a maximum of
two heaters can be commonly vented. See Page 34,
Section 8.9. When venting vertically, a maximum of
four heaters can be commonly vented. See Page 35,
Section 8.10.
The heater may also be installed unvented in certain
circumstances according to building ventilation
codes. Refer to the above codes and Page 32,
Section 8.2 for further information. Unvented
operation also requires compliance with the
clearances to combustibles given on Page 6, Figure
10.
The bottom of the vent or air intake terminal shall not
be located less than 1' (.3 m) above grade level.
The vent shall not terminate less than 7' (2.1 m)
above grade where located adjacent to public
walkways.
Vent terminal must be installed at a height sufficient
to prevent blockage by snow and building materials
protected from degradation by flue gasses.
Secure all joints with #8 x 3/8 sheet metal screws.
Seal all joints with high temperature silicone sealant.
Vent terminal must be beyond any combustible
overhang.
8.1.1 United States Requirements
Vent must terminate at least 3' (.9 m) above any
forced air inlet located within 10' (3.1 m).
Vent must terminate at least 4' (1.2 m) below, 4'
(1.2 m) horizontally from, or 1' (.3 m) above any door,
operable window, or gravity air inlet into any building.
8.1.2 Canadian Requirements
The vent shall not terminate within 6' (1.8 m) of a
mechanical air supply inlet to any building.
The vent shall not terminate within 3' (.9 m) of a
window or door that can be opened in any building,
any non-mechanical air supply inlet to any building,
or of the combustion air inlet of any other appliance.
8.2 Unvented Operation
Sufficient ventilation must be provided in the amount
of 4 cfm per 1000 Btu/h firing rate (United States); 3
cfm per 1000 Btu/h firing rate (Canada).
Use of optional outside combustion air is not
recommended with unvented heaters.
If exhaust fans are used to supply ventilation air, an
interlock switch must be used to prevent the heater
from coming on when the fans are off. This may be
done using a pressure switch.
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 P/N 90502100 (Tjernlund
VH1-4) 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 P/N 90502101 (Tjernlund
VH1-6) 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 35, 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.
WARNING
Carbon Monoxide Hazard
Heaters installed unvented must
be interlocked with sufficient
building exhaust.
Heaters must be installed
according to the installation
manual.
Failure to follow these
instructions can result in death
or injury.