American Dryer Corp. ML-175DR Phase 7 User manual

ML-175DR Installation Manual
Phase 7 / Non-Coin / DSI
with Fire Suppression System
AmericanDryerCorporation
88Currant Road
FallRiverMA02720-4781
Telephone:[phone] / Fax:[phone]
E-mail:[e-mail]
www.amdry.com
ADCPartNo.113406
WARNING: Foryoursafetytheinformationin
thismanual mustbe followedto minimizethe
riskof fireor explosionor toprevent property
damage,personalinjury or death.
— Donot storeoruse gasolineor other flammable
vapors and liquids in the vicinity of this or any
otherappliance.
— WHATTODO IFYOUSMELLGAS:
• Donottryto lightany appliance.
• Donottouch anyelectricalswitch;do not
useanyphoneinyourbuilding.
• Cleartheroom, building orareaofall
occupants.
• Immediatelycallyourgassupplierfroma
neighbor’s phone. Followthegassupplier’s
instructions.
• Ifyoucannotreach yourgas supplier,call
thefiredepartment.
— Installationand servicemustbe performedby a
qualified installer, service agency or the gas
supplier.
AVERTISSEMENT: Assurez-vous de bien
suivrelesinstructionsdonnéesdanscettenotice
pourréduire auminimumle risqued’incendie
ou d’explosion ou pour éviter tout dommage
matériel,touteblessureou lamort.
— Ne pas entreposer ni utiliser d’essence ni
d’autres vapeurs ou liquides inflammables à
proximité de cet appareil ou de tout autre
appareil.
— QUEFAIRESIVOUSSENTEZUNEODEUR
DEGAZ:
• Nepastenter d’allumerd’appareils.
• Netouchez àaucun interrupteur. Nepas
vousservirdes téléphonessetrouvant dans
lebâtiment.
• Évacuezlapièce,le bâtimentoulazone.
• Appelezimmédiatementvotrefournisseur
degazdepuisunvoisin. Suivezles
instructionsdufournisseur.
• Sivousnepouvezrejoindrelefournisseur
degaz,appelez leservicedes incendies.
— L’installationetl’entretiendoiventêtreassuréspar
uninstallateurou unserviced’entretienqualifié
ouparle fournisseurdegaz.

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 efficient, trouble free, and most importantly, safe 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.
“IMPORTANTNOTETOPURCHASER”
Informationmustbeobtainedfromyourlocalgassupplierontheinstructions
tobefollowed iftheusersmells gas. Theseinstructionsmustbeposted ina
prominentlocationnearthedryer.
FORYOUR SAFETY
Donot storeor usegasoline or
otherflammablevaporsand
liquidsinthevicinityofthisor
anyotherappliance.
POURVOTRESÉCURITÉ
Nepas entreposer niutiliserd’essence
nid’autresvapeursouliquides
inflammablesàproximitédecet
appareilou detoutautre 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. The illustrations included in this manual may not depict your particular dryer exactly.
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. Whenordering replacementparts fromthe factory,
you can FAX your order to ADC at [phone] or telephone your order directly to the ADC Parts Department at (508)
678-9000. Pleasespecify the dryermodel numberand serial numberin addition to thedescriptionand partnumber,sothat
your order is processed accurately and promptly.
ML-175DR Phase 7

CHILDRENSHOULDNOTBEALLOWEDTOPLAYONORNEARTHEDRYER(S).
WARNING
CHILDRENSHOULDBESUPERVISEDIFNEARDRYER(S)INOPERATION.
DRYER(S)SHOULDNEVERBELEFTUNATTENDEDWHILEINOPERATION.
CAUTION
FORYOURSAFETY
DONOTDRYMOPHEADSINTHEDRYER.
DONOTUSEDRYERINTHEPRESENCEOFDRYCLEANINGFUMES.
“Caution: Label all wires prior to
disconnection when servicing controls. Wiring
errors can cause improper operation.”
«Attention: Lordesopérations d’entretien
des commandes étiqueter tous fils avant
de les déconnecter. Toute erreur de
câblage peut étre une source de danger et
depanne.»
WARNING
UNDER NO CIRCUMSTANCESshouldthe dryerdoorswitch,thelintdrawerswitch,
or the heat safety circuit ever be disabled.
IMPORTANT
YOUMUSTDISCONNECTANDLOCKOUTTHEELECTRICSUPPLYANDTHEGAS
SUPPLY OR THE STEAM SUPPLY BEFORE ANY COVERS OR GUARDS ARE
REMOVED FROM THE MACHINE TO ALLOW ACCESS FOR CLEANING,
ADJUSTING, INSTALLATION, OR TESTING OFANY EQUIPMENT PER OSHA
(OccupationalSafetyand HealthAdministration)STANDARDS.

WARNING
The dryer must never be operated with any of the back guards, outer tops, or service
panelsremoved. PERSONALINJURYORFIRECOULDRESULT.
IMPORTANT
PLEASEOBSERVEALLSAFETYPRECAUTIONSdisplayedontheequipmentand/or
specified in the installation manual included with the dryer.
WARNING
DRYERMUSTNEVER BE OPERATEDWITHOUTTHELINTFILTER/SCREENIN
PLACE,EVENIFANEXTERNALLINTCOLLECTIONSYSTEMISUSED.
Dryer mustnotbe installed or stored in an area where it willbe exposed to water or weather.
The wiring diagram for the dryer is located in the front electrical control box area.
IMPORTANT
Dryer must be installed in a location/environment, which the ambient temperature
remains between 40° F (4.44° C) and 130° F (54.44° C).

Table of Contents
SECTION I
SAFETY PRECAUTIONS ..............................................................................................................................2
SECTION II
SPECIFICATIONS ..........................................................................................................................................4
A. Specifications.......................................................................................................................................... 4
SECTION III
INSTALLATION PROCEDURES ................................................................................................................6
A. Location Requirements........................................................................................................................... 6
B. Unpacking/Setting Up............................................................................................................................. 7
C. Dryer Enclosure Requirements .............................................................................................................. 9
D. FreshAir Supply Requirements ............................................................................................................ 10
E. Exhaust Requirements.......................................................................................................................... 11
F. Electrical Information ........................................................................................................................... 17
G. Gas Information .................................................................................................................................... 20
H. Steam Information ................................................................................................................................ 24
I. Preparation for Operation/Start-Up...................................................................................................... 28
J. Preoperational Tests ............................................................................................................................. 29
K. Compressed Air Requirements............................................................................................................. 31
L. Shutdown Instructions .......................................................................................................................... 32
SECTION IV
SERVICE/PARTS INFORMATION ...........................................................................................................33
A. Service .................................................................................................................................................. 33
B. Parts...................................................................................................................................................... 33
SECTION V
WARRANTY INFORMATION ...................................................................................................................34
A. Returning Warranty Cards ................................................................................................................... 34
B. Warranty ............................................................................................................................................... 34
C. Returning Warranty Parts..................................................................................................................... 34
SECTION VI
ROUTINE MAINTENANCE ......................................................................................................................36
A. Cleaning ................................................................................................................................................ 36
B. Adjustments .......................................................................................................................................... 38
C. Lubrication ............................................................................................................................................ 38
SECTION VII
MANUAL RESET BURNER HI-LIMIT INSTRUCTIONS ..................................................................39
SECTION VIII
DATA LABEL INFORMATION .................................................................................................................40
SECTION IX
PROCEDURE FOR FUNCTIONAL CHECK OF REPLACEMENT COMPONENTS ...................41
SECTION X
FIRE SUPPRESSION SYSTEM ..................................................................................................................43

2 American Dryer Corp. 113406-1
SECTIONI
SAFETYPRECAUTIONS
WARNING: Foryoursafety,theinformationinthismanualmustbefollowed to minimizetherisk of
fireorexplosion ortopreventproperty damage,personalinjury,or loss oflife.
WARNING: Thedryermust never beoperated with anyofthe backguards,outer tops,or
servicepanelsremoved. PERSONALINJURYORFIRECOULD 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 ALLoccupants.
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. 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. DONOTdryarticles spottedor washedin dry
cleaningsolvents, a combustibledetergent,or“all purpose”cleaner. EXPLOSION
COULDRESULT.
WARNING: DONOT dry rags orarticles coatedorcontaminated withgasoline, kerosene, oil,paint,
orwax. EXPLOSION COULDRESULT.
WARNING: DONOTdrymopheads. Contamination bywaxor flammablesolventswill createa
firehazard.
WARNING: DONOT useheat for dryingarticles thatcontainplastic, foam,spongerubber,or
similarlytexturedrubberlikematerials. Dryinginaheatedbasket(tumbler)maydamage
plasticsor rubberandmay bea firehazard.

113406-1 www.amdry.com 3
7. A program shouldbeestablished for the inspection and cleaning of lint in the burner area, exhaust ductwork,
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 collectionoflintinthe burnerareaandexhaust ductworkcancreateapotential 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 in Canada, the Canadian Electrical
Codes Parts 1 & 2 CSA C22.1-1990 or LATEST EDITION.
NOTE: Failuretoelectricallygroundthe dryer properlywillVOIDTHEWARRANTY.
9. UNDER NO CIRCUMSTANCES should the dryer door switch, the lint drawer switch, or the heat
safety circuit ever be disabled.
WARNING: PERSONALINJURYOR FIRECOULD RESULTSHOULDTHEDRYER
DOORSWITCH,THELINTDRAWER SWITCH,ORTHE HEATSAFETY
CIRCUITEVER BEDISABLED.
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 leftin thedryerafterthedryingand coolingcycles havebeencompletedcan
createa firehazard.
12. DO NOT operate steam dryers with more than 125 psi (8.62 bar) steam pressure. Excessive steam
pressure can damage the steam coil and/or harm personnel.
13. Replace leaking flexible steam hoses or other fixtures immediately. DO NOT operate the dryer with
leaking flexible hoses. PERSONAL INJURY MAY RESULT.
14. READ AND FOLLOW ALL CAUTION AND DIRECTION LABELS ATTACHED TO THE DRYER.
15. For safety, proper operation, and optimum performance, the dryer must not be operated with a load less
than sixty-six percent (66%), 112 lbs (51 kg) of its rated capacity.
WARNING: YOUMUSTDISCONNECTANDLOCKOUTTHEELECTRIC SUPPLYAND
THEGASSUPPLYORTHE STEAMSUPPLYBEFOREANYCOVERSOR
GUARDSAREREMOVEDFROMTHE MACHINETOALLOWACCESS
FORCLEANING,ADJUSTING,INSTALLATION,ORTESTINGOFANY
EQUIPMENTPEROSHA(OccupationalSafetyandHealthAdministration)
STANDARDS.
IMPORTANT: Dryer mustbeinstalledinalocation/environment,whichthe ambient
temperatureremains between40°F (4.44°C) and130°F (54.44°C).

4 American Dryer Corp. 113406-1
SECTIONII
SPECIFICATIONS
A. SPECIFICATIONS
Shaded areas are stated in metric equivalents
IMPORTANT: Gasdryers andsteam dryersmust beprovided witha clean,dry, regulated80 psi+/-
10 psi (5.51 bar +/- 0.68 bar) air supply.
NOTE: ADCreserves therighttomakechanges inspecifications atanytimewithoutnotice or
obligation.
MAXIMUMCAPACITY(DRYWEIGHT) 170 lb 77.11 kg
TUMBLERDIAMETER 51-1/2” 130.81 cm
TUMBLER DEPTH 42-3/4” 108.59 cm
TUMBLERVOLUME 51.50 cu ft 1.458 cu m
TUMBLER/DRIVE MOTOR 3 hp 2.24 kW
BLOWER/FAN MOTOR 7-1/2 hp 5.59 kW
DOOR OPENING(DIAMETER) 31-3/8” 79.71 cm
DOOR SILLHEIGHT 36-1/2” 92.71 cm
WATER CONNECTION 3/4”-11.5 NH
DRYERS PER 20’/40’ CONTAINER 3 / 7
DRYERS PER 48’/53’ TRUCK 8 / 8
VOLTAGE AVAILABLE 208-575v 3ø 3,4w 50/60 Hz
APPROX. NET WEIGHT 1,848 lb 838.24 kg
APPROX. SHIPPING WEIGHT 2,014 lb 913.54 kg
AIRFLOW 3,700 cfm 104.77 cmm
HEATINPUT 395,000 Btu/hr 99,538 kcal/hr
EXHAUST CONNECTION (DIAMETER) 12” 30.48 cm
COMPRESSED AIR CONNECTION 1/4” Quick Connection
COMPRESSED AIR VOLUME 4.25 cfh 0.12 cmh
INLET PIPE CONNECTION 1-1/2” F.N.P.T.
VOLTAGE AVAILABLE
N / A
APPROX. NET WEIGHT
APPROX. SHIPPING WEIGHT
AIRFLOW
EXHAUST CONNECTION (DIAMETER)
COMPRESSED AIR CONNECTION
COMPRESSED AIR VOLUME
OVEN SIZE
kW Btu/hr kcal/hr
VOLTAGE AVAILABLE
N / A
APPROX. NET WEIGHT
APPROX. SHIPPING WEIGHT
AIRFLOW
STEAM CONSUMPTION
OPERATING STEAM PRESSURE
EXHAUST CONNECTION (DIAMETER)
COMPRESSED AIR CONNECTION
COMPRESSED AIR VOLUME
BOILER HP (NORMAL LOAD)
SUPPLYCONNECTION
RETURN CONNECTION
GasSteam Electric

113406-1 www.amdry.com 5
NOTE: ADCreserves therighttomakechanges inspecifications atanytimewithoutnotice or
obligation.
SPECIFICATIONS – GASAND STEAM

6 American Dryer Corp. 113406-1
SECTIONIII
INSTALLATIONPROCEDURES
Installation should be performed by competent technicians in accordance with local and state codes. In the
absence of these codes, the installation mustconform to applicableAmerican National Standards:ANSI Z223.1-
LATEST EDITION (National Fuel Gas Code) orANSI/NFPANO. 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 CSAC22.1-1990 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 installation must conform to applicable 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).
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: “Thedryermustbeinstalledonnoncombustiblefloorsonly.”
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
Requirements in Section D).
5. Clearance provisions mustbe 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. The dryer must be installed with a proper exhaust duct connection to the outside 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: Dryershouldbelocatedwherea minimumamountofexhaust ductwill be necessary.
9. The dryer must be installed with adequate clearance for air openings into the combustion chamber.

113406-1 www.amdry.com 7
CAUTION: Thisdryer producescombustiblelint andmustbeexhausted tothe outdoors. Every6
months,inspecttheexhaustductingandremoveanylintbuildup.
IMPORTANT: Dryer mustbeinstalledinalocation/environment,whichthe ambient
temperatureremains between40°F (4.44°C) and130°F (54.44°C).
B. UNPACKING/SETTING UP
Remove protective shipping material (i.e., plastic wrap and/or optional shipping box) from dryer.
IMPORTANT: Dryermustbetransported andhandledinan uprightpositionatALLtimes.
The dryer can be moved to its final location while still attached to the skid or with the skid removed. To remove
skid from 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 (10.16 cm) square metal shims or other suitable material under the base
pads (refer to the illustration above). It is suggested that the dryer be tilted slightly to the rear.
b. The V-belts are disconnected from the basket (tumbler) drive motor for shipping. Reconnect V-belts
before starting the dryer.

8 American Dryer Corp. 113406-1
2. If more headroom is needed when moving the dryer into position, the top console (module) may be removed.
To RemoveTop Console (module):
a. Disconnect the ground wire (A in the illustration below) located at the rear upper left corner of the
dryer.
b. Remove the eight (8) sets of nuts and washers (B in the illustration below) holding the console
(module) to the base.
c. Disconnect the white plug connector (C in the illustration below) located on the top of the rear
electric service/relay box (provides power to the heat circuit).
d. Disconnect air connection from the 3-way micro valve.
e. Lift the console (module) off of the dryer base.
IMPORTANT: Thedryermustbe transportedand handled inanupright position atALLtimes.

113406-1 www.amdry.com 9
C. DRYER ENCLOSURE REQUIREMENTS
Even though a 12-inch (30.48 cm) clearance is acceptable, it is recommended that the rear of the dryer be
positioned approximately 24-inches (60.96 cm) from the 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 front. A2-inch (5.08 cm) clearance is required between
the bulkhead facing and the top of the dryer.
NOTE: Bulkheadfacing shouldnotbeinstalleduntilafter thedryeris in place. Ceilingareamustbe
locateda minimum of12-inches(30.48 cm)abovethe dryertopconsole(module) and
18-inches(45.72 cm)forsteam models.
NOTE: Whenfiresprinkler systemsarelocatedabove thedryers,aminimum of18-inches(45.72cm)
abovethedryer console(module)isrequired. Dryers maybepositionedsidewall tosidewall,
however,1or 2-inches(2.54 or 5.08cm) issuggestedfor easeof installationand
maintenance. Allowancesmustbemadeforthe opening andclosingof thecontroldoor and
thelintdoor.

10 American Dryer Corp. 113406-1
D. FRESH AIR SUPPLYREQUIREMENTS
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. The dryer
must be installed with provisions for adequate combustion and make-up air supply.
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 4 square feet (0.37 square meters) is required for each gas dryer and a
minimum of 4.75 square feet (0.44 square meters) for each steam 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 six (6) dryers, two (2) unrestricted openings measuring 3 feet by 4 feet (0.91 meters
by 1.22 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-upairmustbeprovidedfrom asourcefree ofdrycleaning solventfumes.
Make-upairthatiscontaminatedbydrycleaningsolventfumeswillresultin
irreparabledamage tothemotors andotherdryer components.
NOTE: ComponentfailureduetodrycleaningsolventfumeswillVOIDTHEWARRANTY.

113406-1 www.amdry.com 11
E. EXHAUST REQUIREMENTS
1. General Exhaust Ductwork Information
Exhaust ductwork shouldbe 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. The dryer must be installed with a proper exhaust duct connection to the outside.
CAUTION: Thisdryer producescombustiblelint andmustbeexhausted totheoutdoors.
CAUTION: IMPROPERLY SIZEDORINSTALLEDEXHAUSTDUCTWORKCAN
CREATEAPOTENTIALFIREHAZARD.
NOTE: When a dryer isexhausted separately, itis recommendedthat a back draftdamper be
installed.
NOTE: Whendryersare exhaustedintoamultiple (common)exhaustline,each dryer mustbe
suppliedwith abackdraft 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 should not
exceed 15 feet (4.57 meters). In the case of multiple (common) dryer venting, the distance from the last
dryer to the outside exhaust outlet should not exceed 15 feet (4.57 meters). The shape of the ductwork
is not critical as 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 three (3) elbows should be used in the exhaust duct
run. If more than three (3) elbows are used, the cross-sectional area of the ductwork must be increased
in proportion to the number of elbows used.
ALL ductwork shouldbe 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 ductwork joints must 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: Exhaustback pressuremeasuredby amanometer intheexhaust ductmustbenoless
than 0 and mustnot exceed0.3 inches (0.74 mb) of water column (W.C.).
NOTE: Whentheexhaust ductwork passesthroughawall,ceiling, orroofmadeofcombustible
materials,the opening mustbe2-inches (5.08cm)larger thantheduct (all thewayaround).
Theductmustbecenteredwithinthisopening.

12 American Dryer Corp. 113406-1
NOTE: Asper theNationalFuel GasCode, “ExhaustductsforType2 clothesdryers shallbe
constructedofsheetmetalor othernoncombustible material. Suchductsshallbeequivalentin
strengthandcorrosion resistancetoducts made ofgalvanizedsheet steelnotlessthan 26
gauge(0.0195-inches[0.5mm]) thick.”
IMPORTANT: Itis recommendedthatexhaustor boosterfans notbe usedinthe exhaustductwork
system.
Outside Ductwork Protection
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.
IMPORTANT: DONOT usescreens, louvers,or capson theoutside openingof the exhaust
ductwork.
2. Single DryerVenting
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 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° and/or 45° angles
instead. The shape of the exhaust ductwork is not critical as long as the minimum cross section area is
provided.
IMPORTANT: Theminimumduct sizeforagas unitis12-inches(30.48 cm)foraround ductand
10-inchesx 10-inches(25.4cm x25.4cm) forasquare duct. Theminimumduct size
fora steamunit is20-inches(50.80 cm)for around duct and18-inches x
18-inches (45.72 cm x 45.72 cm) for a square duct. THE DUCTSIZEMUST
NOTBE REDUCEDANYWHEREDOWNSTREAMOFTHEDRYER.

113406-1 www.amdry.com 13
IMPORTANT: Exhaustback pressure measuredbya manometerateach basket(tumbler)exhaust
duct area mustbeno less than 0 and must not exceed0.3 inches (0.74 mb) of water
column(W.C.).
It is suggested that the ductwork from each dryer not exceed 15 feet (4.57 meters) with no more than three
(3) elbows (excluding dryer connections). If the ductwork exceeds 15 feet (4.57 meters) or has numerous
elbows, the cross-sectional area of the ductwork must be increased in proportion to the length and number
of elbows in it. In calculating duct size, the cross-sectional area of a square or rectangular duct must be
increased twenty percent (20%) for each additional 15 feet (4.57 meters). The diameter of a round
exhaust duct should be increased ten percent (10%) for each additional 10 feet (3.04 meters). Each 90º
elbow is equivalent to an additional 40 feet (12.19 meters), and each 45º elbow is equivalent to an additional
20 feet (6.09 meters).
IMPORTANT: Forextended ductworkruns, thecross sectionarea oftheductwork canonly be
increasedto an extent. Maximumproportionalductwork runscannotexceed 15feet
(4.57meters)more thanthe originallimitationsof15 feet(4.57meters)withthree (3)
elbows. Whentheductworkapproachesthe maximum limitsas notedinthismanual,
aprofessionalheating,ventilating,andair-conditioning(HVAC)firmshouldbe
consultedforproperventinginformation.
ALL ductwork shouldbe 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 ductwork joints must 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.

14 American Dryer Corp. 113406-1
NOTE: Whentheexhaust ductwork passesthroughawall,ceiling, orroofmadeofcombustible
materials,the openingmust be2-inches(5.08 cm)largerthan the duct(allthe wayaround).
Theductmustbe centeredwithinthis opening.
Outside Ductwork Protection
To protect the outside end of the 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
eithercase, allow at least twice the diameterof theduct between theduct openingand thenearest obstruction.
IMPORTANT: DONOT usescreens, louvers,or capson theoutside openingof the exhaust
ductwork.
3. Multiple Dryer (Common) Venting
If it is not feasible to provide separate exhaust ducts for each dryer, ducts from individual dryers may be
channeled into a “common main duct.” The individual ducts should enter the bottom or side of the main
duct at an angle not more than 45° in the direction of the flow and should be spaced at least 55-3/4”
(141.61 cm) apart. The main duct should be tapered, with the diameter increasing before each individual
18-inch (45.72 cm) duct is added.
IMPORTANT: Thedryer isnotprovidedwitha backdraftdamper. Whenexhausted into amultiple
(common)exhaust line,aback draftdampermustbeinstalledat eachdryerduct.
IMPORTANT: Nomore than three (3) dryersshouldbe connected toone (1)main commonduct.
The main duct may be any shape or cross-sectional area, as long as the minimum cross section area is
provided. The illustrations on page 16 show the minimum cross section area for multiple dryer round or
square venting. These figures must be increased 10 square inches (64.52 square centimeters) when
rectangular main ducting is used, and the ratio of duct width to depth should not be greater than 3-1/2 to
1. These figures must be increased in proportion if the main duct run to the last dryer to where it exhausts
to the outdoors is unusually long (over 15 feet [4.57 meters]) or has numerous elbows (more than three [3])
in it. In calculating ductwork size, the cross-sectional area of a square or rectangular duct must be
increased twenty percent (20%) for each additional 20 feet (6.09 meters). The diameter of a round
exhaust must be increased ten percent (10%) for each additional 20 feet (6.09 meters). Each 90° elbow
is equivalent to an additional 40 feet (12.19 meters) and each 45° elbow is equivalent to an additional 20
feet (6.09 meters).
IMPORTANT: Forextended ductworkruns, thecross sectionarea oftheductwork canonly be
increasedto an extent. Maximumproportionalductwork runscannotexceed 15feet
(4.57meters)more thanthe originallimitationsof15 feet(4.57meters)withthree (3)
elbows. Whentheductworkapproachesthe maximum limitsas notedinthismanual,
aprofessionalheating,ventilating,andair-conditioning(HVAC)firmshouldbe
consultedforproperventinginformation.
IMPORTANT: Exhaustback pressuremeasuredby amanometer intheexhaust ductmustbenoless
than 0 and mustnot exceed0.3 inches (0.74 mb) of water column (W.C.).

113406-1 www.amdry.com 15
The ductwork 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 ductwork joints must 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.
NOTE: Whentheexhaust ductwork passesthroughawall,ceiling, orroofmadeofcombustible
materials,the openingmust be2-inches(5.08 cm)largerthan the duct(allthe wayaround).
Theductmustbecenteredwithin thisduct.
Outside Ductwork Protection
To protect the outside end of the horizontal ductwork from the weather, a 90° elbow bent downward
should be installed where the exhaust exits the building. If the exhaust 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.
IMPORTANT: DONOT usescreens, louvers,or capson theoutside openingof the exhaust
ductwork.

16 American Dryer Corp. 113406-1
MULTIPLE DRYER VENTING (GAS DR MODELS)
WITH 12” (30.48 CM) DIAMETER (3700 CFM [104.77 CMM]) CONNECTIONSAT COMMON DUCT
MULTIPLE DRYERVENTING (STEAM MODELS)
WITH 20” (50.8 CM) DIAMETER (4400 CFM [124.59 CMM]) EXHAUST CONNECTIONAT COMMON DUCT