American Dryer Corp. ML-96D User manual

ADCPartNo.113125
For replacement parts, contact the reseller from which the dryer
was purchased or
AmericanDryerCorporation
88Currant Road
FallRiverMA02720-4781
Telephone:[phone] / Fax:[phone]
E-mail:[e-mail]
www.amdry.com
020200RF/pb
WARNING: Foryoursafetythe
informationinthismanualmustbe
followedtominimizetheriskoffireor
explosionortopreventpropertydamage,
personalinjuryor death.
Donotstoreoruse gasoline orotherflammable
vaporandliquidsinthevicinityofthis orany
otherappliance.
WHAT DOYOU DO IFYOU SMELLGAS
* Donottry to lightanyappliance.
* Donottouchanyelectrical switch; do notuse
anyphoneinyourbuilding.
* Cleartheroom,building orareaofall
occupants.
* Immediatelycallyourgassupplierfroma
neighbor'sphone. Followthegas supplier's
instructions.
* Ifyoucannotreach yourgassupplier, callthe
firedepartment.
Installationandservicemust beperformedbya
qualifiedinstaller,serviceagencyorthe gas
supplier.
AVERTISSEMENT: Assurez-vousde bien
suivrelesinstructions donnéesdanscette
noticepourréduireauminimumlerisque
d’incendieoud’explosion oupourévitertout
dommagematériel,toute blessureoulamort.
Nepasentreposerniutiliser d’essence ni
d’autresvapeursouliquidesinflammablesdans
levoisinagedecetappareiloudetoutautre
appareil.
QUEFAIRE SIVOUSSENTEZ UNE ODEUR
DEGAZ:
* Nepastenterd’allumerd’appareil.
* Netouchezàaucuninterrupteur. Ne pas
vousservirdestéléphonesse trouvant dans
lebâtimentoùvousvoustrouvez.
* Évacuezlapièce,le bâtimentoulazone.
* Appelezimmédiatementvotrefournisseurde
gazdepuisunvoisin. Suivezlesinstructions
dufournisseur.
* Sivousnepouvezrejoindrele fournisseur
degaz,appelezleservice des incendies.
L’installationetl’entretiendoiventêtreassurés
paruninstallateurouunserviced’entretien
qualifiéouparlefournisseurde gaz.
ML-96D
Installation Manual

Retain This Manual In ASafe Place For Future Reference
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 manual included with
the dryer.
The following “FOR YOUR SAFETY” caution must be posted near the dryer in a prominent location.
ML-96D
FORYOUR SAFETY
Donotstore or use gasoline or
otherflammablevaporsor
liquidsinthevicinityofthisor
anyotherappliance.
POURVOTRESÉCURITÉ
Nepasentreposerniutiliserd’essence
nid’autresvapeursouliquides
inflammablesdans levoisinagedecet
appareiloudeyoutautreappareil.
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:
DATEOFPURCHASE ____________________________ MODELNO. __________________________________________
RESELLER’SNAME _______________________________________________________________________________________
Serial Number(s) ________________________________________________________________________________________
________________________________________________________________________________________
________________________________________________________________________________________
Replacement parts can be obtained from your reseller or the ADCfactory. When ordering replacementparts from thefactory,
you can FAX your order to ADC at [phone] or telephone your order directly to the ADC Parts Department at
[phone]. Pleasespecifythe dryer modelnumber andserialnumberin addition to thedescriptionandpartnumber,so
that your order is processed accurately and promptly.
“IMPORTANTNOTETOPURCHASER”
Informationmustbeobtainedfromyourlocalgassupplierontheinstructions
tobefollowedifthe user smellsgas. Theseinstructionsmustbepostedina
prominentlocationnearthedryer.

IMPORTANT
YOUMUSTDISCONNECTandLOCKOUTTHEELECTRICSUPPLYandTHEGAS
SUPPLYBEFOREANYCOVERSorGUARDSAREREMOVEDFROMTHEMACHINE
TOALLOWACCESS FORCLEANING,ADJUSTING,INSTALLATION,orTESTING
OF ANY EQUIPMENT per OSHA (Occupational Safety and Health Administration)
STANDARDS.
CHILDRENSHOULDNOTBEALLOWEDTOPLAYONORNEARTHEDRYERS.
WARNING
CHILDRENSHOULDBESUPERVISEDIFNEARDRYERSINOPERATION.
DRYER(S)SHOULDNEVERBELEFTUNATTENDEDWHILEINOPERATION.
CAUTION
FORYOURSAFETY
DONOTDRYMOPHEADSINTHEDRYER.
DONOTUSEDRYERINTHEPRESENCEOFDRYCLEANINGFUMES.
WARNING
UNDER NO CIRCUMSTANCES should thedryerdoorswitches, lintdoorswitch,heat
safety circuit ever be disabled.
“Caution: Label all wires prior to
disconnection when servicing controls. Wiring
errors can cause improper operation.”
«Attention: Lordes opérationsd’entretien
des commandes étiqueter tous fils avant
de les déconnecter. Toute erreur de
câblage peut étre une source de danger et
depanne.»

WARNING
The dryer must never be operated with any of the back guards, outer tops, or service
panelsremoved. PERSONALINJURYorFIRE COULDRESULT.
IMPORTANT
PLEASEOBSERVEALLSAFETYPRECAUTIONSdisplayedontheequipmentand/or
specified in the installation manual included with the dryer.
Dryersmust not be 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.
DRYERMUSTNEVER BEOPERATEDWITHOUTTHELINTFILTER/SCREENIN
PLACE,EVENIFANEXTERNALLINTCOLLECTIONSYSTEMISUSED.
WARNING

Table of Contents
SECTION I
IMPORTANT INFORMATION............................................................................... 3
A. ReceivingandHandling ............................................................................................................... 3
B. SafetyPrecautions ...................................................................................................................... 4
SECTION II
SPECIFICATIONS/COMPONENT IDENTIFICATION........................................... 6
A. Specifications ............................................................................................................................. 6
B. ComponentIdentification ............................................................................................................ 8
SECTION III
INSTALLATION PROCEDURES ..........................................................................10
A. LocationRequirements ............................................................................................................. 10
B. Unpacking/SettingUp ............................................................................................................... 11
C. DryerEnclosureRequirements .................................................................................................. 13
D. FreshAirSupply....................................................................................................................... 14
E. Exhaust Requirements .............................................................................................................. 15
F. ElectricalInformation ................................................................................................................ 19
G. GasInformation ........................................................................................................................ 22
H. PreparationForOperation/Start-Up ......................................................................................... 25
I. PreoperationalTests ................................................................................................................. 26
J. OperatingInstructions ............................................................................................................... 27
K. ShutDownInstructions ............................................................................................................. 28
SECTION IV
SERVICE/PARTS INFORMATION.......................................................................29
A. Service ..................................................................................................................................... 29
B. Parts ........................................................................................................................................ 29
SECTION V
WARRANTY INFORMATION ...............................................................................30
A. ReturningWarrantyCard(s) ...................................................................................................... 30
B. Warranty .................................................................................................................................. 30
C. ReturningWarrantyPart(s)........................................................................................................ 30
SECTION VI
ROUTINE MAINTENANCE...................................................................................32
A. Cleaning ................................................................................................................................... 32
B. Adjustments ............................................................................................................................. 33
C. Lubrication ............................................................................................................................... 33

SECTION VII
PROCEDURE FOR FUNCTIONAL CHECK OF REPLACEMENT
COMPONENTS .......................................................................................................34
SECTION VIII
DATA LABEL/LOCATION INFORMATION......................................................36
SECTION IX
BURNER and BASKET (TUMBLER)/LINT CHAMBER MANUAL RESET
HI-LIMIT INSTRUCTIONS...................................................................................38

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 packaging, and wooden
skid should 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, 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. 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 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. It is your responsibility to file freight claims. Dryer
or 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 theADC Traffic Manager at [phone].
IMPORTANT:The basket (tumbler) section of the dryer must be transported and handled in an
upright position at ALLtimes.

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 or 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. Dryers must be exhausted to the outdoors.
6. Although ADC produces a very versatile dryer, 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 COULD RESULT.
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 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. 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 heating unit area, exhaust
ductwork, 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 ductwork 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 Electrical Code ANSI/NFPA NO. 70-LATEST EDITION or CAN/CGA-B149.2-M91 (Liquid
Propane [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).
NOTE:Failure to do so will VOID 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. READ and FOLLOWALLCAUTIONandDIRECTIONLABELSATTACHEDTOTHEDRYER.
13. For safety, proper operation, and optimum performance, the dryer must not be operated with a load less
than sixty-six percent (66%), 62 pounds (28 kg) of its rated capacity.
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
SECTION II
SPECIFICATIONS/COMPONENT IDENTIFICATION
A. SPECIFICATIONS
IMPORTANT: Dryer must be supplied with clean, dry, and regulated air pressure at 80 PSI ± 10
PSI (5.51 bars ± 0.68 bars).
NOTE:ADCreserves the right to make changes in specifications at any time without notice or
obligation.
GAS
MAXIMUM CAPACITY (DRY WEIGHT) 95 lbs. 43.1 kg
BASKET (TUMBLER) DIAMETER 42" 106.7 cm
BASKET (TUMBLER) DEPTH 29-1/4" 74.3 cm
BASKET (TUMBLER) MOTOR 1/2 HP 0.373 kw
BLOWER MOTOR 3 HP 2.238 kw
DOOR OPENING (DIAMETER) 30-3/4" 78.1 cm
BASKET (TUMBLER) VOLUME 23.5 cu. ft. 0.67cu. m.
DRYERS PER 20'/40' CONTAINER 10/20
DRYERS PER 45'/48' TRUCK 24/24
VOLTAGE AVAILABLE 208-460v 3ø 3, 4w 50/60 Hz
APPROX. WEIGHT (UNCRATED) 878 lbs. 453.6 kg
APPROX. WEIGHT (CRATED) 1,000 lbs. 544.3 kg
HEAT INPUT 350,000 btu/hr 88,200 kcal/hr
AIRFLOW 2,700 cfm 76.5 cmm
INLET PIPE CONNECTION* 1" N.P.T.
COMPRESSED AIR VOLUME 4 cfh 0.12 cmh
COMPRESSED AIR CONNECTION 1/8" F.P.T.
Shaded areas are stated in metric equivalents
*Size of piping varies with installation conditions.

7
NOTE:ADCreserves the right to make changes in specifications at any time without notice or
obligation.
Specifications
ML-96D

8
B. COMPONENT IDENTIFICATION
1. Dryer Front View
Illus. No. Description
1Microprocessor Control/Keyboard (touch pad) Panel Assembly (controls)
2Control (top access) Door Assembly
3Main Door Assembly
4Lint Panel Assembly
5Lint Door
6Wire Diagram (located behind control door)
7Top Console (module) Assembly

9
Illus. No. Description
1Electrical Service Connections
2Top Console
3Heating Unit
4Relay/Wiring Box
5Data Label and Installation Label
6Air Connection
7Exhaust Transition Piece
8Optional Exhaust Damper Assembly - if damper option was purchased at time dryer order was
placed; the damper must be installed at time of dryer installation. If damper option was
purchased, the damper is shipped inside the dryer basket (tumbler).
2. Dryer Rear View

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 toapplicable American NationalStandards:ANSIZ223.1-
LATEST EDITION (National Fuel Gas Code) or ANSI/NFPA NO. 70-LATEST EDITION (National Electrical
Code) or in Canada, the installation must conform to applicable Canadian Standards: CAN/CGA-B149.1-M91
(Natural Gas) or CAN/CGA-B149.2-M91 (Liquid Propane [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, or in Canada, the Canadian Installation Codes: CAN/CGA-B149.1-M91 (Natural Gas) or CAN/
CGA-B149.2-M91 (L.P. Gas) or LATEST EDITION.
1. The dryer must be installed on a sound level floor capable of supporting its weight. Carpeting must be
removed from the floor area that the dryer is to rest on.
IMPORTANT: “The dryer must be installed on noncombustible floors only.”
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 Supplyin
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 as noted in this manual (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 this 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 optional shipping box) from dryer.
IMPORTANT:Dryer must be transported and handled in an upright position at ALLtimes.
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.
To increase bearing life and improve efficiency, the dryer should be tilted slightly to the rear.
The ML-96 is not provided with a back draft damper. The damper is available as a dryer "cost" option. If this
damper option was purchased, for shipping purposes the 16-inches (40.64 cm) butterfly damper assembly is
shipped in the basket (tumbler) of the dryer. For assembly of this damper assembly (refer to the illustrationon
page 9).

12
1. Leveling Dryer
To level dryer, place 4-inch (10.16 cm) square metal shims (refer to the illustrationon page 11) or other
suitable material under the base pads. It is suggested that the dryer be tilted slightly to the rear. If more
headroom is needed when moving dryer into position, the top console (module) may be removed.
a. To remove top console (module).
NOTE:DO NOT have power connected when separating the top console.
1) Disconnect the ground wire (A) at the rear of dryer.
2) Remove the six (6) sets of nuts and washers (B) holding the console (module) to base. (Located
within control boxes.)
3) Open control door and control panel then disconnect the following:
a) On the right side box, disconnect the 4-pin and 2-pin plug. Also remove the air connection at the
union.
b) On the left side box, disconnect the drive and blower motor wires, along with the two (2) "red"
and "black" wires.
4) Lift the console (module) off of the dryer base (C).
IMPORTANT:The dryer must be transported and handled in an upright position at ALLtimes.

13
C. DRYER ENCLOSURE REQUIREMENTS
Even though a 30-inch (76.2 cm) clearance is acceptable, it is recommended that the rear of the dryer be
positioned approximately 36-inches (91.44 cm) from nearest obstruction (i.e. wall) for ease of installation,
maintenance and service. Bulkheads and partitions should be made from noncombustible materials. The
clearance between the bulkhead header and the dryer must be a minimum of 4-inches (10.16 cm) and must not
extend more than 4-inches (10.16 cm) to the rear of the dryer front. The bulkhead facing mustnot be closed in
ALL the way to the top of the dryer. A 2-inch (5.08 cm) clearance is required.
NOTE:Bulkhead facing should not be installed until after dryer is in place. Ceiling area must be
located a minimum of 12-inches (30.48 cm) above the top of the dryer.
NOTE:When fire sprinkler systems are located above the dryers, a minimum of 18-inches (45.72 cm)
above the dryer console (module) is suggested. Dryers may be positioned sidewall to sidewall
however, 1 or 2 inches (2.54 cm or 5.08 cm) is suggested between dryers (or wall) for ease of
installation and maintenance. Allowances must be made for the opening and closing of the
control and lint doors.

14
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 airmust 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 airflow of 2,700 cfm (cubic feet per minute) - 76.45
cmm (cubic meters per minute) - must be supplied to 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 dryer.
To compensate for the use of registers or louvers used over the openings, this make-up airmust beincreased 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 six (6) dryers, two (2) unrestricted openings measuring 3 feet by 3 feet
(0.91 meters by 0.91 meters), 18 square feet (1.67 square meters) 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 the motors and other dryer components.
NOTE:Component failure due to dry cleaning solvent fumes will VOID THE WARRANTY.

15
E. EXHAUST REQUIREMENTS
1. 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) switches, burner hi-limits, or basket (tumbler) hi-heat
thermostats.
CAUTION:DRYER MUST BE EXHAUSTED TO THE OUTDOORS.
CAUTION:IMPROPERLY SIZED or INSTALLED EXHAUSTDUCTWORKCAN
CREATE APOTENTIALFIREHAZARD.
NOTE:When a dryer is exhausted separately, it is recommendedthat a back draft damper be
installed.
NOTE:When dryers are exhausted into multiple (common) exhaust lines, each dryer must be supplied
with a back draft damper.
The 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. When single
dryer venting is used, the ductwork from the dryer to the outside exhaust outlet must not exceed20 feet
(6.1 meters). In the case of multiple (common) dryer venting, the distance from the last dryer to the outside
exhaust outlet must not exceed20 feet (6.1 meters). The shape of the ductwork is not critical so long as
the minimum cross section area is provided. It is suggested that the use of 90º turns in ducting be avoided;
use 30º or 45º angles instead. The radius of the elbows should preferably be 1-1/2 times the diameter of
the duct. Excluding basket (tumbler) or dryer elbow connection in the exhaust duct run. If more than two
(2) elbows are used, the cross section area of the ductwork must be increased in proportion to the number
of elbows added.
ALL ductwork should be smooth inside with no projections from the 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 ductwork jointsmust be taped to prevent moisture and lint from escaping into the building.
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 each basket (tumbler) duct area
must not exceed 0.3 inches (0.75 mb) of water column (W.C.).
IMPORTANT:When the exhaust ductwork passes through a wall, ceiling, or roof made of
combustible materials, the opening must be 2-inches (5.08 cm) larger than the duct
(ALL the way around). The duct must be centered within this opening.
a. Outside Ductwork Protection
1) To protect the outside end of horizontal ductwork from the weather, a 90° elbow bent downward
should be installed where the exhaust exits the building. If the ductwork 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.

16
2. Single Dryer Venting
Where possible, it is suggested to provide a separate exhaust duct for each dryer. The exhaust ductshould
be laid out in such a way that the ductwork 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° or 45° angles instead.
The shape of the exhaust ductwork is not critical so long as the minimum cross section area is provided.
IMPORTANT: Minimum duct size for a dryer is 16-inches (40.64 cm) for a round duct or 14-1/4"
(36.2 cm) for a square duct. THE DUCT SIZE MUST NOT BE REDUCED
ANYWHERE DOWNSTREAM OF DRYER.
IMPORTANT: Exhaust back pressure measured by a manometer at each basket (tumbler) exhaust
ductwork area must not exceed 0.3 inches (0.75 mb) of water column (W.C.).
It is suggested that the ductwork from each dryer be a minimum of 16-inches (40.64 cm) for horizontal runs
with no more than one (1) elbow and 18-inches (45.72 cm) for vertical runs with no more than three (3)
elbows without exceeding 20 feet (6.1 meters) (excluding dryer connections and outside exhaust outlets). If
the duct exceeds 20 feet (6.1 meters) or has numerous elbows, the cross section area of the ductwork must
be increased in proportion to the length and number of elbows in it. In calculating duct size, the cross
section area of a square or rectangular ductmust be increased by twenty percent (20%) for each additional
20 feet (6.1 meters). The diameter of a round exhaust duct should be increased ten percent (10%) for
each additional 15 feet (4.57 meters). Each 90º elbow is equivalent to an additional 36 feet (10.97 meters),
and each 45º elbow is equivalent to an additional 18 feet (5.48 meters).
IMPORTANT:DO NOT use screens, louvers, or caps on the outside opening of the exhaust
ductwork.