I.C.E. MTI 11-300 - Manual (Page 5)

5
CONNECTING THE FLUE (VENTING)
OUTDOORS INSTALLATIONS
AIR FOR COMBUSTION
Openings for combustion air must be provided in a panel (door) with direct access to the
vestibule area where the burners and draft inducer are located. This air opening must be of
sufficient size to provide a suitable supply of air for combustion to the burner compartment,
but not less than one (1) square inch free area per every 8000 Btu per hour of the specified
maximum input rate. The minimum dimension of any air opening should not be less than 3
inches. Heating appliance must be installed so that air access to inlet opening is
unobstructed.
VENTING
The vent termination must be located in accordance with the National Fuel Codes (ANSI
Z223.1) in the US or CAN/CGA-B149 Installation code in Canada.
The venting system for outdoor units is a Category 111, with ve nt products at positive
pressure and up to 500
°
F. The cross-section area of the vent duct or pipe must be at least
equal to the discharge area of the draft inducer.
The discharge opening must always be located in the same pressure zone as the combustion
air inlet.
o For horizontal discharge, the outlet should be located on the same side of the
unit as the combustion air inlet. Never locate the vent outlet on the opposite
side from the combustion air inlet opening.
o For Horizontal discharge where the flue gases need to be vented vertically,
the preferred flue gas discharge should terminate in an exterior flue riser that
extends at least to the top of the cabinet and is open at the top and bottom.
This riser must be located on the same side of the appliance as the
combustion air opening.
INDOOR INSTALLATIONS
AIR FOR COMBUSTION
The furnace must be installed in a location with adequate clearances to provide for an
adequate combustion air space, service and inspection, and proper clearance for
combustible construction. The furnace shall be located in such a manor that it does not
interfere with the circulation of air in the heated space.
All fuel burning equipment must be supplied with air that enters into the combustion
process and is then vented outdoors. Sufficient air must enter the appliance location to
replace the air exhausted through the vent system. Do not install appliances in a confined
space without providing wall opening to and from this space, if building construction is
such that the normal infiltration does not provide sufficient air for combustion and venting,
outside air must be introduced in accordance with ANSI Z223.1 (Sect. 1.3.4.2 and 1.3.4.3).
Install air openings that provide that provides a total free area in accordance with the
following: