6
Figure 3
Equipment Located in Confined Spaces; All
Air from Outdoors Through Ventilated Attic.
See 5.3.3-b.
3. When communicating with the outdoors through hori-
zontal ducts, each opening shall have a minimum free
area of 1 square inch per 2,000 BTU per hour of total
input rating of all equipment in the enclosure. (Figure 4)
*If the appliance room is located against an outside wall and the air openings communicate
directly with the outdoors, each opening shall have a free area of not less than one square inch
per 4,000 BTU per hour of the total input rating of all appliances in the enclosure.
Figure 4
Equipment Located in Confined Spaces; All
Air from Outdoors. See 5.3.3-b.
4. When ducts are used, they shall be of the same cross-
sectional area as the free area of the openings to which
they connect. The minimum dimension of rectangular
air ducts shall not be less than 3 inches.
5.3.4 Specially Engineered Installations:
The requirements of 5.3.3 shall not necessarily govern
when special engineering, approved by the authority hav-
ing jurisdiction, provides an adequate supply of air for
combustion, ventilation, and dilution of flue gases.
5.3.5 Louvers and Grilles:
In calculating free area in 5.3.3, consideration shall be
given to the blocking effect of louvers, grilles or screens
protecting openings. Screens used shall not be smaller
than 1/4 inch mesh. If the area through a design of louver
or grille is known, it should be used in calculating the size
of opening required to provide the free area specified. If the
design and free area is not known, it may be assumed that
wood louvers will have 20-25 percent free area and metal
louvers and grilles will have 60-75 percent free area.
Louvers and grilles shall be fixed in the open position or
interlocked with the equipment so that they are opened
automatically during equipment operation.
5.3.6 Special Conditions Created by Mechanical Ex-
hausting or Fireplaces:
Operation of exhaust fans, ventilation systems, clothes
dryers, or fireplaces may create conditions requiring spe-
cial attention to avoid unsatisfactory operation of installed
gas utilization equipment.
IV. Category I Venting (Vertical Venting)
WARNING
To prevent possible death or personal injury
due to asphyxiation, Amana Non-
Condensing Gas Fired Warm Air Furnaces
must be Category I vented. Do not vent any
of these furnaces using Category III venting.
Category I Venting is venting at a non-positive pressure. A
furnace vented as Category I is considered a fan-assisted
appliance and does not have to be “gas tight.” NOTE:
Single stage gas furnaces with induced draft blowers draw
products of combustion through a heat exchanger allowing
in some instances common venting with natural draft appli-
ances (i.e. water heaters).
All installations must be vented in accordance with National
Fuel Gas Code, NFPA 54/ANSI Z223.1 - latest edition. In
Canada, the furnaces must be vented in accordance with
the National Standard of Canada, CAN/CGA B149.1 and .2
- latest editions and amendments.
NOTE: The vertical height of the Category I venting system
must be at least as great as the horizontal length of the
venting system.
WARNING
To prevent possible death or personal injury
due to asphyxiation, common venting with
other manufacturer’s induced draft
appliances is not allowed.
Common venting with specific Amana Category I 80%
furnaces is allowed with the addition of a common vent kit
(CVK) for each appliance. Contact the local installing dealer,
distributor or Amana directly for more information.
