Odyssey
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Installation and Operation Instructions - General Venting
CT80-250
14
5.0 GENERAL VENTING
Natural Draft Applications
All Odyssey models are certified as Natural Draft boilers. The Natural Draft installation draws combustion air
from the room and uses the stack effect and draft system to exhaust flue gases using a chimney.
Air Supply - Allowances for combustion air must be supplied to the appliance space, due to the fact that the
heating appliance consumes large volumes of combustion air. In most instances, a permanent opening with an
unobstructed or “free area” of 1 square inch for every 1000 BTU’s of input will provide a sufficient amount of
combustion air for the boiler to operate properly. If the building is fairly new and relatively air tight, compensate
for the air tightness by using a “free area” that is 15% larger that what was calculated above. Do not place the
boiler in, or adjacent to, a room where an exhaust fan is operating. Refer to “Combustion Air” in Section 6.0
Natural Draft Applications for more details. Installation must comply with Standard CSA B139 (Canada) and
NFPA 31 (USA).
Stack Draft - Sufficient draft by natural or mechanical means is necessary for ensuring optimal and consistent
operation. The appliance should have a stack draft sufficient to support stable operation. See Draft Settings
(Natural Draft).
Avoiding Condensation - Due to the high combustion efficiencies and low stack gas
temperatures, great care must be taken to ensure that the chimney isn’t subjected to gas
condensation. The exhaust gas temperature where the flue pipe enters the chimney must be a minimum of 240
o
F
or condensation may occur.
Draft Regulator - A draft regulator must be used and set to regulate the draft of the boiler. Make sure that the
damper is free to operate without sticking, for this will affect the boiler’s combustion system. It is important that
the draft be adequate because poor draft conditions will cause poor operation and a possible hazardous condition.
Draft Settings (Natural Draft) -
The Odyssey is designed to operate with a -.03” w.c.
draft in the flue breaching; therefore, ensure there is enough natural or mechanical draft
for proper operation. Due to the design of the Odyssey it may operate at a positive over fire pressure up to +.20 at
a -.03 draft.
Direct Vent Applications
Odyssey models C85-150 are also certified for direct vent applications. The Direct Vent installation uses a special
venting system where exhaust gases are vented directly to the outside using a special venting system which
equalizes the pressure between the air inlet and the flue outlet resulting in a balanced flue system. Refer to Section
7.0 Direct Vent Applications for more details. Installation must comply with Standard CSA B139 (Canada) and
NFPA 31 (USA).
Draft Settings (Direct Vent) -
Due to the design of the balanced flue system, the Odyssey
will operate at a positive draft pressure and a positive over fire pressure at all times. It is
designed to operate with a maximum stack draft of 0.25” w.c and a maximum over fire draft of 0.33” w.c. when
little or no wind is present. In extreme wind conditions, the maximum stack draft is 0.35” w.c. and the maximum
over fire draft is 0.45” w.c.
