J801X Installation Manual

9
• Sheet metal fasteners should be used to secure the vent
pipe to the furnace flue. However, the NFGC states that
alternative vent products may be attached according to
the vent manufacturers instructions.
• When an existing furnace is removed from a vent system
serving other appliances, the existing vent system may no
longer be sized to properly vent the remaining appliances.
An improperly sized venting system can result in the
formation of condensate, leakage, or spillage. The existing
vent system should also be checked to make sure it remains
in compliance with NFGC. If it isn’t, the vent system must
be brought into compliance before installing the furnace.
Horizontal Venting
• Horizontal vent systems must be sealed with a high
temperature sealant that can withstand temperatures of
450° F. Recommended sealants: Dow Corning Sealant
736 RTV; GE 106 RTV; High Tech Ind., High TEMP RED.
• This furnace is not approved for horizontal venting without
the use of an add-on power venter. Power venters establish
negative pressure in the vent piping and the furnace
operates as if connected to a Category I vertical vent. The
power venter is only for use when exhausting through an
exterior wall.
• The power venter must be installed according to the
instructions provided by the power venter manufacturer
and applicable requirements of local codes. For Canadian
installations please refer to the Canadian Installation Code
(CAN/CSA-B149.1 or 2) and/or local codes.
• The outlet of the vent must be at least 12 inches above
the highest expected snow accumulation.
Flexible Vent Systems
Flexible venting systems are approved for use providing
they are listed for the application and meet all local Code
requirements. These systems are primarily used to line
existing masonry chimneys. They must be sized to the
application according to the sizing tables in the National
Fuel Gas Code, including the required 20% reduction in
maximum capacity.
Flexible venting systems are permitted to be used as the
vent connector. However, great care must be taken to ensure
that there are no sags in the venting system which could
accumulate condensate. The flexible vent system must be
supported at no more than 5 foot intervals and maintain a
minimum slope of ¼ inch per foot of horizontal run.
CIRCULATING AIR REQUIREMENTS
WARNING:
Do not allow combustion products to enter the
circulating air supply. Failure to prevent the
circulation of combustion products into the
living space can create potentially hazardous
conditions including carbon monoxide poisoning
that could result in personal injury or death.
All return ductwork must be secured to the
furnace with sheet metal screws. For installations
in confined spaces, all return ductwork must be
adequately sealed. When return air is provided
through the bottom of the furnace, the joint
between the furnace and the return air plenum
must be air tight.
The surface that the furnace is mounted on must
provide sound physical support of the furnace
with no gaps, cracks or sagging between the
furnace and the floor or platform.
Return air and circulating air ductwork must
not be connected to any other heat producing
device such as a fireplace insert, stove, etc. This
may result in fire, explosion, carbon monoxide
poisoning, personal injury, or property damage.
Plenums & Air Ducts
• Plenums and air ducts must be installed in accordance with
the Standard for the Installation of Air Conditioning and
Ventilating Systems (NFPA No. 90A) or the Standard for
the Installation of Warm Air Heating and Air Conditioning
Systems (NFPA No. 90B).
• On upflow furnaces, if the maximum airflow is 1,600 CFM
or more, two openings shall be used for return air to comply
with government mandated efficiency standards.
• It is recommended that the outlet duct contain a removable
access panel. The opening should be accessible when the
furnace is installed in service and shall be of a size that
smoke or reflected light may be observed inside the casing
to indicate the presence of leaks in the heat exchanger.
The cover for the opening shall be attached in such a
manner as to prevent leaks.
• If outside air is used as return air to the furnace for
ventilation or to improve indoor air quality, the system must
be designed so that the return air is not less than 60° F
(15° C) during operation. If a combination of indoor and
outdoor air is used, the ducts and damper system must
be designed so that the return air supply to the furnace is
equal to the return air supply under normal, indoor return
air applications.
• When a cooling system is installed which uses the furnace
blower to provide airflow over the indoor coil, the coil must
be installed downstream (on the outlet side) of the furnace
or in parallel with the furnace.
• If a cooling system is installed in parallel with the furnace, a
damper must be installed to prevent chilled air from entering
the furnace and condensing on the heat exchanger. If a