American Dryer Corp. ML-130 II User manual

ADC Part No. 113002
For replacement parts, contact the distributor from which the dryer
was purchased or
American Dryer Corporation
88 Currant Road
Fall River MA 02720-4781
Telephone: [phone] / Fax: [phone]
E-mail: [email protected]
WARNING: For your safety the
information in this manual must be
followed to minimize the risk of fire or
explosion or to prevent property damage,
personal injury or death.
Do not store or use gasoline or other flammable
vapor and liquids in the vicinity of this or any
other appliance.
WHAT DO YOU DO IF YOU SMELL GAS
*Do not try to light any appliance.
*Do not touch any electrical switch; do not use
any phone in your building.
*Clear the room, building or area of all
occupants.
*Immediately call your gas supplier from a
neighbor's phone. Follow the gas supplier's
instructions.
*If you cannot reach your gas supplier, call the
fire department.
Installation and service must be performed by a
qualified installer, service agency or the gas
supplier.
AVERTISSEMENT: Assurez-vous de bien
suivre les instructions données dans cette
notice pour réduire au minimum le risque
d’incendie ou d’explosion ou pour éviter tout
dommage matériel, toute blessure ou la mort.
Ne pas entreposer ni utiliser d’essence ni
d’autres vapeurs ou liquides inflammables dans
le voisinage de cet appareil ou de tout autre
appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR
DE GAZ:
*Ne pas tenter d’allumer d’appareil.
*Ne touchez à aucun interrupteur. Ne pas
vous servir des téléphones se trouvant dans
le bâtiment où vous vous trouvez..
*Évacuez la pièce, le bâtiment ou la zone.
*Appelez immédiatement votre fournisseur de
gaz depuis un voisin. Suivez les instructions
du fournisseur.
*Si vous ne pouvez rejoindre le fournisseur
de gaz, appelez le service des incendies.
L’installation et l’entretien doivent être assurés
par un installateur ou un service d’entretien
qualifié ou par le fournisseur de gaz.
ML-130
Installation Manual
070398JEV/abe

Retain This Manual In A Safe Place For Future Reference
Replacement parts can be obtained from your distributor or the ADC factory. When ordering replacement parts from the
factory, you can FAX your order toADC at [phone] or telephone your orders directly to the ADCPartsDepartmentat
[phone]. Please specify the dryermodelnumber andserialnumberin addition to thedescription andpartnumber,so
that your order is processed accurately and promptly.
Theillustrationson the following pages may not depict your particular dryer exactly. The illustrations are a composite of the
various dryer models. Be sure to check the descriptions of the parts thoroughly before ordering.
DATE OF PURCHASE MODEL NO.
DISTRIBUTORS NAME
Serial Number(s)
ML-130
“IMPORTANT NOTE TO PURCHASER”
Information must be obtained from your local gas supplier on the instructions
to be followed if the user smells gas. These instructions must be posted in a
prominent location near the dryer.
American Dryer Corporation products embody advanced concepts in engineering, design, and safety. If this product is
properly maintained, it will provide many years of safe, efficient, and trouble-free operation.
ONLY qualified technicians should service this equipment.
OBSERVEALL SAFETY PRECAUTIONS displayed on the equipment or specified in the installation/operator's manual
included with the dryer.
The following “FOR YOUR SAFETY” caution must be posted near the dryer in a prominent location.
FOR YOUR SAFETY
Do not store or use gasoline or
other flammable vapors or liquids
in the vicinity of this or any other
appliance.
POUR VOTRE SÉCURITÉ
Ne pas entreposer ni utiliser d’essence
ni d’autres vapeurs ou liquides
inflammables dans le voisinage de cet
appareil ou de yout autre appareil.
We have tried to make this manual as complete as possible and hope you will find it useful. ADC reserves the right to make
changes from time to time, without notice or obligation, in prices, specifications, colors, and material, and to change or
discontinue models.
Important
For your convenience, log the following information:

IMPORTANT
YOU MUST DISCONNECT and LOCKOUT THE ELECTRIC SUPPLY and THE GAS
SUPPLY or THE STEAM SUPPLY BEFORE ANY COVERS or GUARDS ARE
REMOVEDFROMTHEMACHINETOALLOWACCESS FORCLEANING,ADJUST-
ING, INSTALLATION, or TESTING OF ANY EQUIPMENT per OSHA (Occupational
Safety and Health Administration) STANDARDS.
CHILDREN SHOULD NOTBEALLOWED TO PLAY ON OR NEAR THE DRYER(S).
WARNING
CHILDREN SHOULD BESUPERVISED IF NEAR DRYER(S) IN OPERATION.
DRYER(S) SHOULD NEVER BE LEFT UNATTENDED WHILE IN OPERATION.
CAUTION
FOR YOUR SAFETY
DO NOT DRY MOP HEADS IN THE DRYER.
DO NOT USE DRYER IN THE PRESENCE OF DRY CLEANING FUMES.
WARNING
UNDER NO CIRCUMSTANCES should the door switch or the heat circuit devices
ever be disabled.
“Caution: Label all wires prior to
disconnection when servicing controls. Wiring
errors can cause improper operation.”
«Attention: Lordesopérationsd’entretien
des commandes étiqueter tous fils avant
de les déconnecter. Toute erreur de
câblage peut étre une source de danger et
de panne.»

WARNING
The dryer must never be operated with any of the back guards, outer tops, or service
panels removed. PERSONAL INJURY or FIRE COULD RESULT.
IMPORTANT
PLEASE OBSERVEALLSAFETY PRECAUTIONS displayed on the equipment and/or
specified in the installation and operator's manual included with the dryer.
Dryers mustnotbe installed or stored in an area where it will be exposed to water or weather.
The wiring diagram for the dryer is located in the front electrical control box area.
DRYER MUST NEVER BE OPERATED WITHOUT THE LINT FILTER/SCREEN IN
PLACE, EVEN IF AN EXTERNAL LINT COLLECTION SYSTEM IS USED.
WARNING

Table of Contents
SECTION I
IMPORTANT INFORMATION
A. Receiving and Handling ............................................................................................................... 3
B. Safety Precautions ....................................................................................................................... 4
SECTION II
SPECIFICATIONS/COMPONENT IDENTIFICATION
A. Specifications .............................................................................................................................. 7
B. Component Identification............................................................................................................. 8
SECTION III
INSTALLATION PROCEDURES
A. Location Requirements.............................................................................................................. 10
B. Unpacking/Setting Up ................................................................................................................11
C. Dryer Enclosure Requirements .................................................................................................. 13
D. Fresh Air Supply Requirements ................................................................................................. 14
E. Exhaust Requirements............................................................................................................... 15
F. Electrical Information ................................................................................................................ 21
G. Gas Information ........................................................................................................................ 27
H. Steam Information..................................................................................................................... 31
I. Preparation For Operation/Start-Up .......................................................................................... 35
J. Preoperational Tests .................................................................................................................. 36
K. Operating Instructions ................................................................................................................ 39
L. Shut Down Instructions .............................................................................................................. 40
SECTION IV
SERVICE/PARTS INFORMATION
A. Service ..................................................................................................................................... 41
B. Parts ......................................................................................................................................... 41
SECTION V
WARRANTY INFORMATION
A. Returning Warranty Card(s) ...................................................................................................... 42
B. Parts ......................................................................................................................................... 42
C. Returning Warranty Card(s) ...................................................................................................... 42

SECTION VI
ROUTINE MAINTENANCE
A. Cleaning ................................................................................................................................... 44
B. Adjustments .............................................................................................................................. 45
C. Lubrication ............................................................................................................................... 45
SECTION VII
REVERSING TIMER SPIN/DWELL ADJUSTMENTS ..................................46
SECTION VIII
PROCEDURE FOR FUNCTIONAL CHECK OF REPLACEMENT
COMPONENTS .................................................................................................47

3
SECTION I
IMPORTANT INFORMATION
A. RECEIVING and HANDLING
The dryer is shipped in a protective stretch wrap cover with protective cardboard corners and top cover
(or optional box) as a means of preventing damage in transit. Upon delivery, the dryer and/or packaging,
and wooden skidshould be visually inspected for shipping damage. If any damage whatsoever is noticed,
inspect further before delivering carrier leaves.
Dryers damaged in shipment:
1. ALL dryers should be inspected upon receipt and before they are signed for.
2. If there is suspected damage or actual damage, the trucker's receipt should be so noted.
3. If the dryer is damaged beyond repair, itshould be refused. Those dryers which were not damaged in
a damaged shipment should be accepted, but the number received and the number refused must be
noted on the receipt.
4. If you determine that the dryer was damaged after the trucker has left your location, you should call
the delivering carrier's freight terminal immediately and file a claim. The freightcompany considers
this concealed damage. This type of freight claim is very difficult to get paid and becomes extremely
difficult when more than a day or two passes after the freight was delivered. It is your responsibility
to file freight claims. Dryer/parts damaged in transit cannot be claimed under warranty.
5. Freight claims are the responsibility of the consignee, and ALL claims must be filed at the receiving
end. ADC assumes no responsibility for freight claims or damages.
6. If you need assistance in handling the situation, please contact the ADC Traffic Manager at (508)
678-9000.
IMPORTANT:The dryer must be transported and handled in an upright position at all times.

4
B. SAFETY PRECAUTIONS
WARNING:For your safety, the information in this manual must be followed to minimize the risk
of fire or explosion or to prevent property damage, personal injury, or loss of life.
WARNING: The dryer must never be operated with any of the back guards, outer tops, or
service panels removed. PERSONAL INJURY or FIRE COULD RESULT.
1. DO NOT store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
2. Purchaser/user should consult the local gas supplier for proper instructions to be followed in the event
the user smells gas. The instructions should be posted in a prominent location.
3. WHAT TO DO IF YOU SMELL GAS...
a. DO NOT try to light any appliance.
b. DO NOT touch any electrical switch.
c. DO NOT use any phone in your building.
d. Clear the room, building, or area of ALL occupants.
e. Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
f. If you cannot reach your gas supplier, call the fire department.
4. Installation and service must be performed by a qualified installer, service agency, or gas supplier.
5. Dryer(s) must be exhausted to the outdoors.
6. AlthoughADC produces a very versatile machine, there are some articles that, due to fabric composition
or cleaning method, should not be dried in it.
WARNING:Dry only water-washed fabrics. DO NOT dry articles spotted or washed in dry
cleaning solvents, a combustible detergent, or "all purpose" cleaner. EXPLOSION
COULDRESULT.
WARNING:DO NOT dry rags or articles coated or contaminated with gasoline, kerosene, oil,
paint, or wax. EXPLOSION COULD RESULT.
WARNING:DO NOT dry mop heads. Contamination by wax or flammable solvent will create a
fire hazard.
WARNING:DO NOT use heat for drying articles that contain plastic, foam, sponge rubber, or
similarly textured rubberlike materials. Drying in a heated basket (tumbler) may
damage plastics or rubber and also may be a fire hazard.

5
7. A program should be established for the inspection and cleaning of lint in the burner area, exhaust
duct work, and area around the back of the dryer. The frequency of inspection and cleaning can best
be determined from experience at each location.
WARNING:The collection of lint in the burner area and exhaust duct work can create a potential
fire hazard.
8. For personal safety, the dryer must be electrically grounded in accordance with local codes
and/or the NATIONAL ELECTRIC CODE ANSI/NFPA NO. 70-LATEST EDITION, or in Canada, the
CANADIAN ELECTRICAL CODES PARTS 1 & 2 CSA C22.1-1990 or LATEST EDITION.
NOTE:Failure to do so will VOID THE WARRANTY.
9. UNDER NO CIRCUMSTANCES should the dryer door switches, lint drawer switch, or heat safety
circuit, ever be disabled.
WARNING: PERSONAL INJURY or FIRE COULD RESULT.
10. This dryer is not to be used in the presence of dry cleaning solvents or fumes.
11. Remove articles from the dryer as soon as the drying cycle has been completed.
WARNING:Articles left in the dryer after the drying and cooling cycles have been complete can
create a fire hazard.
12. READ and FOLLOWALL CAUTION and DIRECTION LABELS ATTACHED TO THE DRYER.
WARNING: YOU MUST DISCONNECT and LOCKOUT THE ELECTRIC SUPPLY
and THE GAS SUPPLY or THE STEAM SUPPLY BEFORE ANY COVERS
or GUARDS ARE REMOVED FROM THE MACHINE TO ALLOW
ACCESS FOR CLEANING, ADJUSTING, INSTALLATION, or TESTING
OF ANY EQUIPMENT per OSHA (Occupational Safety and Health
Administration) STANDARDS.

6
IMPORTANT:Steam dryers must be provided with a clean, dry, regulated 80 PSI (+/- 10 PSI)
air supply.
NOTE:ADC reserves the right to make changes in specifications at any time, without notice or
obligation.
Gas
Electric
MAXIMUMCAPACITY(DRYWEIGHT)130 lbs. 60 kg
BASKET (TUMBLER)DIAMETER44-1/2" 113 cm
BASKET (TUMBLER)DEPTH42-1/2" 107.9 cm
BASKET MOTOR3/4 HP .560 kw
BLOWERMOTOR3 HP 2.238 kw
DOOROPENING (DIAMETER)31-3/8" 79.7 cm
BASKET (TUMBLER)VOLUME38.2 cu. ft. 1.08 cu.m.
DRYERSPER20'/40' CONTAINER3/7
DRYERSPER45'/48' TRUCK9/9
VOLTAGEAVAILABLE 208-460v 3ø 3, 4w 50/60Hz
HEATINPUT375,000 btu/hr 94,500 kcal/hr
APPROX.WEIGHT(UNCRATED)1,500 lbs. 680.4 kg
APPROX.WEIGHT(CRATED)1,725 lbs. 782.5 kg
AIRFLOW2,150 cfm 60.1 cmm
Inlet Pipe Size 1" 2.54 cm
VOLTAGEAVAILABLE 208-600v 3ø 3, 4w 50/60Hz
OVENSIZE
Kw Btu/Hr kcal/hr Airflow
72 246,150 62,030 2,150 60.1 cmm
80 273,500 68,922 2,500 70.1 cmm
VOLTAGEAVAILABLE 208-460v 3ø 3, 4w 50/60Hz
APPROX.WEIGHT(UNCRATED)1,650 lbs. 748.4 kg
APPROX.WEIGHT(CRATED)1,875 lbs. 850.5 kg
HEATINPUT13 Bhp
STEAMCONSUMPTION 450 lbs/hr 200.2 kg/hr
AIRFLOW2,750 cfm 77.9 cmm
INLET PIPESIZE 1-1/4" 2.54 cm
80 PSI COMPRESSEDAIR1/8" F.P.T. .318 cm
Shaded areas are stated in metric equivalents.
SECTION II
SPECIFICATIONS/COMPONENT IDENTIFICATION
A. SPECIFICATIONS
Steam

7
NOTE:ADCreserves the right to make changes in specifications at any time, without notice or
obligation.
Specifications
MLG-130 (Gas)
MLE-130 (Electric)
MLS-130 (Steam)
EXHAUST
DUCT DIA. DIM. "A" DIM. "B"
GAS and
ELECTRIC 12" (30.5 cm) 11-1/4" (28.6 cm) 9-1/2" (24.1 cm)
STEAM 16" (40.6 cm) 9" (22.9 cm) 9" (22.9 cm)

8
B. COMPONENT IDENTIFICATION
1. DRYER FRONT VIEW
Illus. No. Description
1Microprocessor Control/Keyboard Panel Assembly (Controls)
2Control (Top Access) Door Assembly
3Main Door Assembly
4Lint Door Assembly
5Lint Drawer
6Emergency Stop Button
7Wire Diagram (located behind Control Door)
8Top Console (Module) Assembly

9
2. DRYER REAR VIEW
Illus. No. Description
1Basket (drive) Motor Assembly
2Blower Motor Mount Assembly
3Impellor (fan/blower) Assembly
4Idler Bearing Mount Assembly
5Tumbler Bearing Mount Assembly
6* Electric Service Relay Box
7Heating Unit
8Data Label and Installation Label
* Electric service connections are made in this box.

10
SECTION III
INSTALLATION PROCEDURES
Installation should be performed by competent technicians in accordance with local and state codes. In
the absence of these codes, the installation must conform to applicable AMERICAN NATIONAL
STANDARDS:
ANSI.Z223.1-LATEST EDITION (National Fuel Gas Code)
or
ANSI/NFPA NO. 70-LATEST EDITION (National Electric Code)
In CANADA, the installation must conform to CANADIAN STANDARDS:
CAN/CGA-B149.1-M91 (Natural Gas) or CAN/CGA-B149.2-M91 (L.P. Gas) or LATEST EDITION (for
GENERAL INSTALLATION and GAS PLUMBING)
or
CANADIAN ELECTRICAL CODES PARTS 1 & 2 CSA C22.1-1990 or LATEST EDITION (for
ELECTRICAL CONNECTIONS).
A. LOCATION REQUIREMENTS
Before installing the dryer, be sure the location conforms to local codes and ordinances. In the absence of
such codes or ordinances the location must conform with the National Fuel Gas Code ANSI.Z223.1-
LATEST EDITION.
1. The dryer must be installed on a sound level floor capable of supporting its weight. It is
recommended that carpeting be removed from the floor area that the dryer is to rest on.
2. The dryer must not be installed or stored in an area where it will be exposed to water and/or weather.
3. The dryer is for use in noncombustible locations.
4. Provisions for adequate air supply must be provided as noted in this manual (refer to Fresh Air
Supply in Section D).
5. Clearance provisions must be made from combustible construction as noted in this manual (refer to
Dryer Enclosure Requirements in Section C).
6. Provisions must be made for adequate clearances for servicing and for operation as noted in this
manual (refer to Dryer Enclosure Requirements in Section C).
7. Dryer must be exhausted to the outdoors (refer to Exhaust Requirements in Section E).
8. Dryer must be located in an area where correct exhaust venting can be achieved as noted in the
manual (refer to Exhaust Requirements in Section E).
IMPORTANT:Dryer should be located where a minimum amount of exhaust duct will be
necessary.

11
B. UNPACKING/SETTING UP
Remove protective shipping material (i.e., plastic wrap, and/or optional shipping box) from dryer.
IMPORTANT: Dryer must be transported and handled in an upright position at all times.
The dryer can be moved to its final location while still attached to the skid or with the skid
removed. To un-skid the dryer, locate and remove the four (4) lag bolts securing the base of the dryer to
the wooden skid. Two (2) are at the rear base, and two (2) are located in the bottom of the lint chamber.
To remove the two (2) lag bolts located in the lint chamber area, remove the lint drawer and the three (3)
Phillips head screws securing the lint door in place.
1. LEVELING DRYER
a. To level the dryer, place 4-inch metal shims (refer to
the illustration) or other suitable material under the
base pads. It is suggested that the dryer be tilted
slightly to the rear.
2. If more headroom is needed when moving the dryer
into position, the top console (module) may be removed.
To remove the Top Console (module);
a. Rear of Dryer (refer to the illustration on page 12)...
1) Disconnect the (4) pin “EMERGENCY STOP”
Connector B .
2) Remove the Drive Motor (blue) wires C marked
1, 2, 3 from the Drive Motor Reversing Contactor
T1, T2, T3.
3) Remove the Blower Motor (red) wires D marked
1, 2, 3 from the Blower Motor Overload T1, T2,
T3.
4) Disconnect the (2) pin Rotational Sensor Connector E .
b. Front of Dryer...
1) Open the Control Door
a) Remove the Phillips head screw from the bottom right of the Phase 6 Microprocessor
Controller (computer) Keypad (touchpad) Panel Assembly.
b) Open the keypad door.
2) Disconnect the (4) pin connector.
3) Disconnect the (2) pin connector.

12
4) Disconnect the (2) pin connector from the Phase 6 Microprocessor Controller (computer).
Refer to the wiring diagram on the Control Door.
5) Disconnect the ground (GND) wire from the Phase 6 Microprocessor Controller (computer).
NOTE:b 2 and b 3 apply only to models manufactured after August 1997. Models manufactured
prior August 1997 require a Pin Extraction Tool (ADC Part No. 122800) to remove the
pins from their connectors.
c. Top of Dryer (refer to the illustration below)...
1) Remove the eight (8) sets of nuts and washers F holding the console (module) to the base.
NOTE:The MLS-130 (steam) dryer model is manufactured with a Pneumatic (piston) Damper
System which requires an external supply of clean, dry, regulated air (80 PSI +/- 10 PSI).
Refer to Steam Damper Air System connections...page 33, Section H, item 3.
2) Remove the incoming air line from the Solenoid Valve (for steam models only).
3) Lift the console (module) off of the dryer base.
IMPORTANT:The dryer must be transported and handled in an upright position at all times.

13
C. DRYER ENCLOSURE REQUIREMENTS
Even though a 12-inch clearance is acceptable, it is recommended that the rear of the dryer be positioned
approximately two (2) feet (24-inches) from the nearest obstruction (i.e., wall) for ease of installation,
maintenance, and service. Bulkheads and partitionsshould be made from noncombustible materials. The
clearance between the bulkhead header and the dryer must be a minimum of four (4) inches andmust not
extend more than four (4) inches to the rear of the front. The bulkhead facingmust not be closed in all the
way to the top of the dryer. A 2-inch clearance is required.
NOTE:Bulkhead facing should not be installed until after the dryer is in place. Ceiling area must
be located a minimum of 12-inches above the top of the dryer.
IMPORTANT:Even though a minimum of only 12-inches is required, 18-inches or more is
suggested, for steam dryers and especially in cases where sprinkler heads are over
the dryers.
NOTE:When fire sprinkler systems are located above the dryers, a minimum of 18-inches above
the dryer console (module) is suggested. Dryers may be positioned side wall to side wall
however, 1 or 2-inches is suggested for ease of installation and maintenance. Allowances
must be made for the opening and closings of the control door and the lint door.

14
IMPORTANT:Make-up air must be provided from a source free of dry cleaning solvents fumes.
Make-up air that is contaminated by dry cleaning solvent fumes will result in
irreparable damage the motors and other dryer components.
NOTE: Component failure due to dry cleaning solvent fumes will VOID THE WARRANTY.
D. FRESH AIR SUPPLY REQUIREMENTS
When the dryer is operating, it draws in room air, heats it, passes this air through the basket (tumbler), and
exhausts it out of the building. Therefore, the room air must be continually replenished from the out-
doors. 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 assure proper performance of each dryer.
An unrestricted source of air is necessary for each dryer. An air flow of 2,150 cfm (cubic feet per minute)
must be supplied to each gas dryer and electric dryer with a 72 Kw oven, 2,500 cfm (cubic feet per
minute) must be supplied to each electric dryer with an 80 Kw oven, and 2,750 cfm (cubic feet per
minute) must be supplied to each steam dryer. As a general rule, an unrestricted air entrance from the
outdoors (atmosphere) of a minimum of three (3) square feet is required for each gas dryer and 72 Kw
electric dryer and a minimum of five (5) square feet for each steam dryer and 80 Kw electric dryer.
To compensate for the use of registers or louvers used over the openings, this make-up air must be
increased by approximately thirty-three percent (33%). Make-up air openingsshould 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.
EXAMPLE: For a bank of six (6) dryers, two (2) unrestricted openings measuring 3 feet by
3 feet (18 square feet) is acceptable.
Allowances must be made for remote or constricting passageways or where dryers are located at exces-
sive altitudes or predominantly low pressure areas.

15
E. EXHAUST REQUIREMENTS
1. General Exhaust Duct Work Information
Exhaust duct work should be designed and installed by a qualified professional. Improperly sized
duct work 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) switches, burner hi-limits, or
basket (tumbler) hi-heat thermostats.
CAUTION:DRYER MUST BE EXHAUSTED TO THE OUTDOORS.
CAUTION: IMPROPERLY SIZED OR INSTALLED EXHAUST DUCT WORKCAN
CREATE APOTENTIAL FIREHAZARD.
NOTE:When a dryer is exhausted separately, it is recommended that a back draft damper be
installed.
NOTE:When dryers are exhausted into a multiple (common) exhaust line, each dryer must be
supplied with a back draft damper.
The duct workshould be laid out in such a way that the duct work travels as directly as possible to the
outdoors with as few turns as possible. Single or independent dryer venting is recommended. When
single dryer venting is used, the duct work from the dryer to the outside exhaust outlet should
not exceed (20) feet. In the case of multiple (common) dryer venting, the distance from the last dryer
to the outside exhaust outletshould not exceed (20) feet. The shape of the duct work is not so critical
so long as the minimum cross sectional area is provided. It is suggested that the use of 90º turns be
avoided; use 30º and/or 45º bends/angles instead. The radius of the elbows should preferably be
1-1/2 times the diameter of the duct. Excluding basket (tumbler)/dryer elbow connections or elbows
used for outside protection from the weather, no more than two (2) elbows should be used in the
exhaust duct run. If more than two (2) elbows are used, the cross sectional area of the duct workmust
be increased in proportion to the number of elbows used.
ALL duct work should be smooth inside with no projections from sheet metal screws or other
obstructions which will collect lint. When adding ducts, the duct to be added should overlap the duct
to which it is to be connected. ALL duct work joints must be taped to prevent moisture and lint from
escaping into the building. Inspection door should be installed at strategic points in the exhaust duct
work for periodic inspection and clean-out of lint from the duct work.
IMPORTANT:Exhaust back pressure measured by a manometer in the exhaust duct should not
exceed 0.3 inches of water column.
NOTE:Where the exhaust duct work passes through a wall, ceiling, or roof made of combustible
materials, the opening must be 2-inches larger (all the way around) than the duct. The
duct must be centered within this opening.

16
a. Outside Duct Work Protection
1) To protect the outside end of horizontal duct work from the weather, a 90° elbow bent down-
ward should be installed where the exhaust exits the building. If the duct work travels
vertically up through the roof, it should be protected from the weather by using a 180° turn to
point the opening downward. In either case, allow at least twice the diameter of the duct
between the duct opening and the nearest obstruction.
IMPORTANT:DO NOT use screens or caps on the outside of opening of exhaust duct work.
2. Single Dryer Venting
Where possible, it is suggested to provide a separate exhaust duct for each dryer. The exhaust duct
should be laid out in such a way that the duct work travels as directly as possible to the outdoors with
as few turns as possible. It is suggested that the use of 90° turns in the ducting be avoided; use 30°
and/or 45° angles instead. The shape of the exhaust duct work is not critical so long as the minimum
cross section area is provided.
IMPORTANT:Minimum duct size for a gas dryer or 72 Kw electric dryer is 14-inches for a
round duct 12.50” x 12.50” for a square duct. The minimum duct size for a
steam dryer or 80 Kw electric dryer is 16-inches for a round duct 14.50” x
14.50” for a square duct. THE DUCT SIZE MUST NOT BE REDUCED
ANYWHERE DOWN STREAM OF THE DRYER.
IMPORTANT: Exhaust back pressure measured by a manometer at each basket (tumbler)
exhaust duct area should not exceed 0.3 inches of water column.