American Dryer Corp. AD-236, Installation Manual

Page: 16 / 48

12 American Dryer Corp. 113047 - 21
E. EXHAUST REQUIREMENTS
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 shut down of the burner by the airflow (sail) switches, burner hi-limits, or basket (tumbler) hi-limit thermostats.
The dryer must be installed with a proper exhaust duct connection to the outside.
The design of the flue system shall be such that any condensate formed when operating the appliance from cold
shall either be retained and subsequently re-evaporated or discharged.
CAUTION: This dryer produces combustible lint and must be exhausted to the outdoors.
CAUTION: IMPROPERLY SIZED OR INSTALLED EXHAUST DUCTWORK CAN
CREATE A POTENTIAL FIRE HAZARD.
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. When single dryer venting is used, the length of ductwork from the dryer to the
outside exhaust outlet must not exceed 20 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 exceed 20 feet (6.1 meters). The shape
of the ductwork is not critical so long as the minimum cross-sectional area is provided.
1. Single Dryer Venting
Where possible, it is suggested to provide a separate exhaust duct for each dryer. The exhaust ductwork
should be laid out in such a way that the ductwork travels as directly as possible to the outdoors with as
few turns as possible. It is suggested that the use of 90° turns be avoided; use 30° and/or 45° bends
instead. The radius of the elbows should preferably be 1-1/2 times the diameter of the duct. The shape
of the ductwork is not critical so long as the minimum cross-sectional area is provided.
IMPORTANT: Exhaust back pressure measured by a manometer/magnehelic in the exhaust duct
must be no less than 0 and must not exceed 0.3 in WC (0.74 mb) with both baskets
(tumblers) operating.
NOTE: It is recommended that exhaust or booster fans not be used in the exhaust ductwork system
except where necessary to maintain exhaust back pressure (in the exhaust duct) between zero
and 0.3 inch water column with both baskets (tumblers) operating. Where employed, booster
fans must not activate the dryer airflow proving switch (sail switch) when the dryer is not in
operation.
It is suggested that the ductwork from each dryer must not exceed 20 feet (6.1 meters) with no more than
two (2) elbows. If the ductwork exceeds 20 feet (6.1 meters) or has numerous elbows, the cross-sectional
area of the ductwork must be increased in proportion to the length or number of elbows in it.
IMPORTANT: For extended ductwork runs, the cross-sectional area of the ductwork can only be
increased to an extent. Maximum proportional ductwork runs cannot exceed 20 feet
(6.1 meters) more than the original limitations of 20 feet (6.1 meters) with two (2)
elbows. When the ductwork approaches the maximum limits as noted in this manual,
a professional heating, venting, and air conditioning (HVAC) firm should be consulted
for proper venting information.