12
American Dryer Corp.
113335 - 12
EXAMPLE: For a bank of 6 gas dryers, 2 openings measuring
3 feet by 3 feet (0.91 meters by 0.91 meters) are acceptable.
Allowances must be made for remote or constricting
passageways or where dryers are located at excessive
altitudes or predominantly low pressure areas.
IMPORTANT: Make-up air must be provided from a source
free of dry cleaning solvent fumes. Make-up air that is
contaminated by dry cleaning solvent fumes will result in
irreparable damage to the motors and other dryer
components.
Fresh Air Supply Requirements ______
When the dryer is operating, it draws in room air, heats it,
passes this air through the tumbler, and exhausts it out of
the building. Therefore, the room air must be continually
replenished from the outdoors. If the make-up air is
inadequate, drying time and drying efficiency will be adversely
affected. Ignition problems and sail switch “fluttering”
problems may result, as well as premature motor failure from
overheating.
Air supply (make-up air) must be given careful consideration
to ensure proper performance of each dryer. An unrestricted
source of air is necessary for each dryer. As a general rule,
an unrestricted air entrance from the outdoors (atmosphere)
of a minimum of 3 square feet (0.28 square meters) is required
for each gas, electric, and steam dryer.
To compensate for the use of registers or louvers used over
the openings, this make-up air area must be increased by
approximately thirty-three percent (33%). Make-up air
openings should not be located in an area directly near where
exhaust vents exit the building.
It is not necessary to have a separate make-up air opening
for each dryer. Common make-up air openings are
acceptable. However, they must be set up in such a manner
that the make-up air is distributed equally to all the dryers.
The dryer must be installed with provisions for adequate
combustion and make-up air supply.
NOTE: Component failure due to dry cleaning solvent
fumes will void the warranty.
Exhaust Requirements _______________
General Exhaust Ductwork Information
Exhaust ductwork should be designed and installed by a
qualified professional. Improperly sized ductwork will create
excessive back pressure, which results in slow drying,
increased use of energy, overheating of the dryer, and
shutdown of the burner by the airflow (sail) switch, burner hi-
limit, or tumbler hi-heat thermostat. The dryer must be
installed with a proper exhaust duct connection to the outside.
CAUTION: This dryer produces combustible lint and must
be exhausted to the outdoors.
Improperly sized or installed exhaust ductwork can create
a potential fire hazard.
NOTE: When a dryer is exhausted separately, it is
recommended that a back draft damper be installed.*
When dryers are exhausted into a multiple (common)
exhaust line, each dryer must be supplied with a back draft
damper.*
* Models manufactured as of September 24, 2001, have a damper in the dryer
as a standard item.
IMPORTANT: Exhaust back pressure measured by a
manometer at each tumbler exhaust duct area must be no
less than 0 and must not exceed 0.3 in wc (0.74 mb).
The exhaust ductwork should be laid out in such a way that
the ductwork travels as directly as possible to the outdoors
with as few turns as possible. Single or independent dryer
venting is recommended. It is suggested that the use of
90° turns in ducting be avoided; use 30° and/or 45° angles
instead. The radius of the elbows should preferably be
1-1/2 times the diameter of the duct. The shape of the exhaust
ductwork is not critical as long as the minimum cross-sectional
area is provided.
IMPORTANT: It is recommended that exhaust or booster
fans not be used in the exhaust ductwork system.
NOTE: As per the National Fuel Gas Code, “Exhaust ducts
for type 2 clothes dryers shall be constructed of sheet
metal or other noncombustible material. Such ducts shall
be equivalent in strength and corrosion resistance to ducts
made of galvanized sheet steel not less than 26 gauge
(0.0195-inches [0.50 mm]) thick.”
All ductwork should be smooth inside with no projections from
sheet metal screws or other obstructions, which will collect
lint. When adding ducts, the ducts to be added should overlap
the duct to which it is connected. All ductwork joints must be
taped to prevent moisture and lint from escaping into the
building. Additionally, inspection doors should be installed
at strategic points in the exhaust ductwork for periodic
inspection and cleaning of lint from the ductwork.
IMPORTANT: Exhaust back pressure measured by a
manometer at the dryer exhaust duct area must be no less
than 0 and must not exceed 0.3 in wc (0.74 mb).
