Installation guide

66840/035-20003-001Rev.B(1205)
GAS
GABLE VENT
OPTIONAL TOPABOVE
SOFFIT OUTLET
J
_:_ VENTILATED E_
CRAWL SPACE
AIR SUPPLY OPENINGS AND DUCTS
1. An opening may be used in lieu of a duct to provide to provide the outside air
supply to an appliance unless otherwise permitted by the authority having
jurisdiction• The opening shah be located within 12" (30.5 cm) horizontally from,
the burner level of the appliance. Refer to "AIR SOURCE FROM OUTDOORS
AND VENT AND SUPPLY AIR SAFETY CHECK" in these instructions for
additional information and safety check procedure•
2. The duct shah be either metal, or a material meeting the class 1
requirements of CAN4-S110 Standard for Air Ducts•
3. The duct shah be ]east the same cross-sectional area as the free
area of the air supply inlet opening to which it connects.
4 The duct shah terminate within 12 in (30.5 cm) above, and
• within 24 in (61 cm) horizontally from, the burner ]eve] of
the appliance having the largest input•
GAS
GAS
VENT
AIR (b) AIR (a)
WATER
INLET
HEATER INLET
,R/a)
COMBUSTION AIR SOURCE FROM OUTDOORS
1. Two permanent openings, one within 12 in (30.5 ram) of the top and
one within 12 in (30.5 ram) of bottom of the confined space, Two
GABLE VENT
5. A square or rectangular shaped duct shall only be used vSO_ _
when the required free area of the supply opening is 2.
9 in2 (58•06 cm2) or larger• When a square or rectangular
duct is used, its small dimenstanshall not be less than
3 in (7•6 cm).
6. An att tiger supply fr td hall be equipped with _.... ..... _ _!
a means to prevent the direct entry of rain and wind•
Such means shall not reduce the required free area of
the air supply opening•
7. An air supply inlet opening from the outdoors shall 3.
be located not less than 12" (30•5 cm) above the _As
WATER
outside gradelevel• INLET H_TER NLET 4.
AR b AIR(a)
permanent openings, shall communicate directly or by means of ducts
with the outdoors, crawl spaces or attic spaces•
One permanent openings, commencing within 12 in (30.5 ram)of the
top of the enclosure shall be permitted where the equipment has
clearances of at least 1 in (2.54 cm) from the sides and back and
6 in (15.24 cm) from the front of the appliance. The opening shall
communicate directly with the outdoors and shall have a minimum
free area of:
a. 1 square in per 3000 Btu per hour (6.45 cm20.879 kW) of the total
input rating of all equipment located in the enclosure•
b. Not less than the sum of all vent connectors in the confined space•
The duct shall be least the same cross-sectional area as the free
area of the air supply inlet opening to which it connects•
The blocking effects of louvers, grilles and screens must be given
consideration in calculating free area. If the free area of a specific
louver act grille is not known•
FIGURE 29: Outside and Ambient Combustion Air
kWARNING
When a Category I fumace is removed or replaced, the original
venting system may no longer be correctly sized to properly vent
the attached appliances.
An improperly sized vent system can cause CARBON MONOXIDE
to spill into the living space causing personal injury, and or death.
Ventilated Combustion Air
The ventilated attic space or a crawl space from which the combustion
air is taken must comply with the requirements specified in "AIR
SOURCE FROM OUTDOORS" in this instruction or in Section 5.3, Air
for Combustion and Ventilation of the National Fuel Gas Code, ANSI
Z223.1 (latest edition). This type installation requires a pipe that
extends from the furnace vent connection (top right of unit) to the exte-
rior of the building. Follow all notes, procedures and required materials
in the COMBUSTION AIR SUPPLY section in these instructions when
installing the unit and into a ventilated attic space or crawl space. DO
NOT terminate vent pipe in an Attic or Crawl Space.
Vent and Supply (Outside) Air Safety Check Procedure
For Category I furnaces, vent installations shall be in accordance with
Parts 7 and 11 of the National Fuel Gas Code, ANSI Z223.1/NFPA 54,
and or Section 7 and Appendix B of the CSA B149.1, Natural Gas and
Propane Installation Codes, the local building codes, furnace and vent
manufacture's instructions.
Multistery or common venting systems are permitted and must be
installed in accordance with the National Fuel Gas Code, ANSI Z223.1/
NFPA 54 and / or the CSA B149.1, Natural Gas and Propane Installa-
tion Codes, local codes, and the manufacture's instructions.
Vent connectors serving Category I furnaces shall not be connected
into any portion of mechanical draft systems operating under positive
pressure•
Horizontal portions of the venting system shall be supported to prevent
sagging using hangers or perforated straps and must slope upwards
not less than !/4" per foot (0.635 cm/m) from the furnace to the vent ter-
minal.
It is recommended that you follow the venting safety procedure below•
This procedure is designed to detect an inadequate ventilation system
that can cause the appliances in the area to operate improperly causing
unsafe levels of Carbon Monoxide or an unsafe condition to occur.
Unitary Products Group 19