American Dryer Corp. ML-75HS User manual

ADC Part No. 113001
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: [e-mail]
051697SL/tf
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-75HS
Installation Manual
(Gas/Electric/Steam)

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 to ADC at [phone] or telephone your orders directly to the ADC Parts Department at
[phone]. Please specify the dryer model number and serial number in addition to the description and part number, so
that your order is processed accurately and promptly.
The illustrations on 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)
“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.
OBSERVE ALL 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
REMOVED FROM THE MACHINE TO ALLOW ACCESS FOR CLEANING, ADJUST-
ING, INSTALLATION, or TESTING OFANY EQUIPMENT per OSHA (Occupational
Safety and HealthAdministration) STANDARDS.
CHILDREN SHOULD NOT BEALLOWED TO PLAY ON OR NEAR THE DRYER(S).
WARNING
CHILDREN SHOULD BE SUPERVISED IF NEAR DRYER(S) IN OPERATION.
DRYER(S) SHOULD NEVER BE LEFT UNATTENDED WHILE IN OPERATION.
CAUTION
FOR YOUR SAFETY
DO NOT DRYMOPHEADS IN THE DRYER.
DO NOT USE DRYER IN THE PRESENCE OF DRYCLEANING 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: Lor des opérations d’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 OBSERVE ALL SAFETY PRECAUTIONS displayed on the equipment and/or
specified in the installation/operator's manual included with the dryer.
Dryer(s) must not be installed or stored in an area where it will be exposed to water and/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 ............................................................................... 3
A. Receiving and Handling ............................................................................................................... 3
B. Safety Precautions ....................................................................................................................... 3
SECTION II
SPECIFICATIONS .................................................................................................... 6
A. Specifications .............................................................................................................................. 6
B. Component Identification ............................................................................................................. 8
SECTION III
INSTALLATION PROCEDURES ......................................................................... 10
A. Location Requirements .............................................................................................................. 10
B. Unpacking/Setting Up ............................................................................................................... 11
C. Dryer Enclosure Requirements .................................................................................................. 12
D. Fresh Air Supply ....................................................................................................................... 13
E. Exhaust Requirements ............................................................................................................... 14
F. Electrical Information ................................................................................................................ 19
G. Gas Information ........................................................................................................................ 27
H. Steam Information ..................................................................................................................... 30
I. Preparation For Operation/Start-up .......................................................................................... 36
J. Preoperational Tests .................................................................................................................. 37
K. Preoperational Instructions ........................................................................................................ 39
L. Shut Down Instructions .............................................................................................................. 40
SECTION IV
SERVICE/PARTS INFORMATION ...................................................................... 41
A. Service ..................................................................................................................................... 41
B. Parts ......................................................................................................................................... 41
SECTION V
WARRANTY INFORMATION .............................................................................. 42
A. Returning Warranty Card(s) ...................................................................................................... 42
B. Parts ......................................................................................................................................... 42
C. Returning Warranty Card(s) ...................................................................................................... 42

SECTION VI
ROUTINE MAINTENANCE .................................................................................. 44
A. Cleaning ................................................................................................................................... 44
B. Adjustments .............................................................................................................................. 45
SECTION VII
PROCEDURE FOR FUNCTIONAL CHECK OF REPLACEMENT
COMPONENTS ....................................................................................................... 46
SECTION VIII
REVERSING TIMER SPIN/DWELL ADJUSTMENTS ....................................49
SECTION IX
TECHNICAL INFORMATION ..............................................................................50
Data Label ..................................................................................................................................... 50

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
skid should be visually inspected for shipping damage. f 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. f there is suspected damage or actual damage, the trucker's receipt should be so noted.
3. f the dryer is damaged beyond repair, it should 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. f 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 freight company 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. t 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. f you need assistance in handling the situation, please contact the ADC Traffic Manager at
[phone].
IMPORTANT: The tumbler section of 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 bac 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 F 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. mmediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
f. f you cannot reach your gas supplier, call the fire department.
4. nstallation and service must be performed by a qualified installer, service agency, or gas supplier.
5. Dryer(s) must be exhausted to the outdoors.
6. Although ADC produces a very versatile machine, there are some articles that, due to fabric composition
or cleaning method, should not be dried in it.
WARNING: ry only water-washed fabrics. DO NOT dry articles spotted or washed in dry
cleaning solvents, a combustible detergent, or "all purpose" cleaner.
EXPLOSION COULD RESULT.
WARNING:DO NOT dry rags or articles coated or contaminated with gasoline, kerosene, oil,
paint, wax. EXPLOSION COULD RESULT.
WARNING: DO NOT dry mop heads. Contamination by wax or flammable solvents will create
a fire hazard.
WARNING:DO NOT use heat for drying articles that contain plastic, foam, sponge rubber, or
similarly textured rubber materials. rying 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 heating unit area, exhaust
duct work, and inside 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 ANS /NFPA NO. 70-LATEST ED T ON.
NOTE: Failure to do so will VOI THE WARRANTY.
9. UNDER NO CIRCUMSTANCES should the dryer door switches, lint door switch, 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 completed
can create a fire hazard.
12. DO NOT operate steam dryers with more than 125 PS steam pressure. Excessive steam pressure can
damage steam coil and/or harm personnel.
13. Replace leaking flexible hoses or other steam fixtures immediately. DO NOT operate the dryer with
leaking flexible hoses. PERSONAL INJURY MAY RESULT.
14. The normal PH level for copper type steam coils must be maintained between a value of 8.5 to 9.5.
For steel type steam coils the PH level must be maintained between a value of 9.5 to 10.5. These
limits are set to limit the acid attack of the steam coils.
IMPORTANT: Coil failure due to improper PH level will VOID THE WARRANTY.
15. READ and FOLLO ALL CAUTION and DIRECTION LABELS ATTACHED TO THE DRYER.
WARNING: YOU MUST DISCONNECT and LOCKOUT THE ELECTRIC SUPPLY and
THE GAS 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
BASKET DIAMETER 37" 94 cm
BASKET DEPTH 36" 91.5 cm
BASKET MOTOR 1 HP* .746 kw
DOOR OPENING (Diameter) 31-3/8" 79.7 cm
BASKET VOLUME 22.4 cu. ft. .634 cu.m.
DRYERS PER 20’/40’ CONTAINER 10/20
DRYERS PER 45’/48" TRUCK 24/24
VOLTAGE AVAILABLE 120-460v / 1Ø-3Ø/ 50/60 Hz
APPROX. WEIGHT (Uncrated) 721 lbs. 327 kg
APPROX. WEIGHT (Crated) 771 lbs. 349.7 kg
HEAT INPUT 200,000 btu/hr 50,400 kcal/hr
AIRFLOW 1,200 cfm 33.98 cmm
INLET PIPE SIZE 3/4** 1.91 cm
VOLTAGE AVAILABLE 208-460v / 1Ø-3Ø/ 50/60 Hz
APPROX. WEIGHT (Uncrated) 721 lbs. 327 kg
APPROX. WEIGHT (Crated) 771 lbs. 349.7 kg
AIRFLOW 1,200 cfm 33.98 cmm
VOLTAGE AVAILABLE 120-460v / 1Ø-3Ø/ 50/60 Hz
APPROX. WEIGHT (Uncrated) 757 lbs. 343.4 kg
APPROX. WEIGHT (Crated) 807 lbs. 366.1 kg
AIRFLOW 1,350 cfm 38.23 cmm
COMPRESSED AIR VOLUME .75 cfh .02 cmh
AIR CONNECTION 1/8" F.P.T. .318 cm
STEAM CONSUMPTION BOILER HP NORMAL
LOAD
238.7 lbs./hr 108.3 kg/hr 7
OPERATING STEAM PRESSURE STEAM SUPPLY STEAM SUPPLY
125 psi max 8.6 kg/sq cm 1" 2.54 cm 1" 2.54 cm
SECTION II
SPECIFICATIONS/COMPONENT IDENTIFICATION
A. SPECIFICATIONS
* For non-reversing models.
** A minimum of 3/4" pipe must be supplied to the gas inlet for each dryer.
Shaded areas are stated in metric equivalents.
IMPORTANT: Steam dryers must be provided with 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
Steam

7
NOTE: ADC RESERVES THE RIGHT TO MAKE CHANGES IN SPECIFICATIONS AT
ANY TIME, WITHOUT NOTICE or OBLIGATION.
Specifications
MLG-75HS
MLE-75
MLS-75

8
B. COMPONENT IDENTIFICATION
1. DRYER FRONT V EW
Illus. No. Description
1 Controls
2 Control (top access) Door Assembly
3 Main Door Assembly
4 Lint Compartment Area (lint screen located behind door)
5 Data Label and Installation Label (located behind control [service] door)

9
1. DRYER REAR V EW
NOTE: 1/8-inch Compressed Air Supply Inlet (for Steam Models ONLY) is located behind
the Electric Service Relay Box.
Illus. No. Description
1 Heating Unit
2 1/8" Compressed Air Supply Inlet
(behind Electric Service Relay Box for steam units ONLY)
3* Electric Service Relay Box
4 Tumbler Bearing Mount Assembly
5 Idler Bearing Mount Assembly
6 Blower Motor Assembly
7 Leveling Leg (rear)
8 Basket (Drive) Motor Assembly (Reversing Models ONLY)
9 Dryer Exhaust
* Electric service connections for Gas & Steam Models are made in this box.

10
SECTION III
INSTALLATION PROCEDURES
nstallation should be performed by competent technicians in accordance with local and state codes. n the
absence of these codes, the installation must conform to applicable American National Standards: National Fuel
Gas Code ANS .Z223.1-LATEST ED T ON and/or National Electric Code ANS /NFPA NO. 70-LATEST
ED T ON.
A. LOCATION REQUIREMENTS
Before installing the dryer, be sure the location conforms to local codes and ordinances. n the absence of such
codes or ordinances the location must conform with the National Fuel Gas Code ANS .Z223.1-LATEST
ED T ON.
1. The dryer must be installed on a sound level floor capable of supporting its weight. t 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: ryer 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: ryer 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 unskid the dryer, locate and remove the four (4) bolts securing the base of the dryer to the wooden
skid. Two (2) are at the rear base (remove the back panel for access), and two (2) are located in the bottom of
the lint chamber. To remove the two (2) bolts located in the lint chamber area, remove the lint door.
With the skid removed, to make it easier to slide the dryer into its final position, slightly lower ALL four (4)
leveling legs, so that the dryer will slide on the legs instead of the base frame.
To increase bearing life and improve efficiency, the dryer should be tilted slightly to the rear.
The basket (tumbler) is supported during shipping by a wooden block. REMOVE THIS BLOCK BEFORE
STARTING THE DRYER.
IMPORTANT: For microprocessor (computer) models, this wooden bloc must be removed
before connecting power to the dryer or irreparable damage to the bas et
(tumbler) will result.
The lint coops of ALL ML-75 dryers are supported during shipping by a bracket. REMOVE THIS BRACKET
BEFORE STARTING THE DRYER.
1. Leveling Dryer
The dryer is equipped with four (4) leveling legs, one at each corner of the base. Two (2) are located at
the rear of the dryer base, and two (2) are located in the lint chamber (coop). To increase bearing life and
improve efficiency, the dryer should be tilted slightly to the rear.

12
NOTE: Allowances must be made for opening the control door.
Dryers may be positioned side wall to side wall. However, a 1/16" minimum allowance must be made for
opening and closing of the control door and the lint door. t is suggested that the dryer be positioned about two
(2) feet away from the nearest obstruction for ease of installation, maintenance, and service (to be measured
from the back guard.) (Refer to the illustration above for details.)
NOTE: Air considerations are important for proper and efficient operation.
IMPORTANT: Even though a minimum of only 12-inches is required, 18-inches or more is
suggested. The additional clearance is advantageous for ease of installation and
service.
IMPORTANT: When fire sprinkler systems are located above the dryers, a minimum of
18-inches above the dryer console (module) is required. ryers may be
positioned side wall to side wall however, a 1/16-inch minimum allowance is
required between dryers (or wall) for ease of installation and maintenance.
Allowances must be made for the opening and closings of the control door and
the lint door.
C. DRYER ENCLOSURE REQUIREMENTS
Bulkheads and partitions should be made of noncombustible materials and must be located a minimum of
twelve (12) inches (18-inches or more is recommended for ease of installation, maintenance , and service) above
the dryer outer top, except along the front of the dryer which may be partially closed in if desired. The clearance
between the bulkhead header and the dryer must be a minimum of four (4) inches and must not extend more
than four (4) inches to the rear of the front. The bulkhead facing must not be closed in all the way to the top of
the dryer. A one (1) inch clearance is required.

13
D. FRESH AIR SUPPLY
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 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 assure proper performance of each dryer. An
unrestricted source of air is necessary for each dryer. An air flow of 1,200 cfm (cubic feet per minute) must be
supplied to each gas and electric dryer and 1,350 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 1-1/2
square feet is required for each 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 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.
EXAMPLE: For a bank of four (4) dryers, two (2) unrestricted openings measuring 2 feet by
1-1/2 feet (6 square feet) is 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 motors and other dryer components.
NOTE: Component failure due to dry cleaning solvent fumes will VOI THE WARRANTY.

14
E. EXHAUST REQUIREMENTS
1. General Exhaust Duct Work nformation
Exhaust duct work should be designed and installed by a qualified professional. mproperly
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: RYER MUST BE EXHAUSTE TO THE OUT OORS.
CAUTION: IMPROPERLY SIZED OR INSTALLED EXHAUST DUCT WORK CAN
CREATE A POTENTIAL FIRE HAZARD.
The duct work 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. Single or independent dryer venting is
recommended.
Horizontal Venting:
When single dryer venting is used, the length of duct work, from the dryer to the outside exhaust outlet,
should not exceed fifteen (15) feet. The minimum diameter of this duct work must be at least 10-inches
(even though the dryer exhaust duct for gas and electric units is only 8-inches). n the case of multiple
(common) dryer venting, the distance from the last dryer to the outside exhaust outlet should not exceed
fifteen (15) feet. The shape of the duct work is not critical so long as the minimum cross-sectional area is
provided. t is suggested that the use of 90° turns 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. ncluding 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. f more than two (2) elbows are used, the cross sectional area of
the duct work must be increased. 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. nspection doors should be installed at strategic points in the exhaust
duct work for periodic inspection and clean-out of lint from the duct work.
Vertical Venting:
When single dryer venting is used the length of the duct work from the dryer to the outside exhaust outlet
should not exceed twenty (20) feet. The minimum diameter of this duct work must be at least 12-inches
(even though the dryer exhaust duct for gas and electric units is only 8-inches) n the case of multiple
(common) dryer venting, the distance from the last dryer to the outside exhaust outlet should not exceed
twenty (20) feet. The shape of the duct work is not so critical so long as the minimum cross sectional area is
provided. t is suggested that the use of 90º turns be avoided; use 30º and/or 45º bends instead.. The
radius of the elbows should preferably be 1-1/2 times the diameter of the duct. 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. nspection doors
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.

15
IMPORTANT: Minimum duct work diameter for horizontal venting is 10-inches and for vertical
venting the minimum is 12-inches..
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.
a. Outside Duct Work Protection
1) To protect the outside end of horizontal duct work from the weather, a 90° elbow bent
downward should be installed where the exhaust exits the building. f 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. n 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. t 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 dryer that is vented horizontally is 10-inches for a round
duct or an equivalent of 80 square inches. 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.
IMPORTANT: Minimum duct size for a dryer that is vented vertically is 12-inches for a round duct or
an equivalent of 120 square inches. The DUCT SIZE MUST NOT BE
REDUCED ANYWHERE DOWN STREAM OF THE DRYER.

16
IMPORTANT: For extended duct work runs, the cross section area of the duct work can only be
increased to an extent. When the duct work approaches the maximum limits
noted in this manual, a professional heating venting air conditioning (HVAC)
firm should be consulted for proper venting information.
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. nspection doors should be installed at strategic points in the exhaust duct
work for periodic inspection and clean-out of lint from the duct work.
NOTE: Where the exhaust duct 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.
a. Outside Duct Work Protection
1) To protect the outside end of horizontal duct work from the weather, a 90° elbow bent downward
should be installed where the exhaust exits the building. f 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. n 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.