19
IMPORTANT:
For extended ductwork runs, the cross section area of the duct can only be increased
to an extent. Maximum proportional ductwork runs
cannot
exceed 20 feet (6.09
meters) more than the original limitations of 20 feet (6.09 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.
ALL
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:
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 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 nearest obstruction.
IMPORTANT:
DO NOT
use screens, louvers, or caps on the outside opening of 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 airflow and
should be
spaced at least 48-3/8 inches
(122.87 cm) apart. The main duct
should be
tapered, with the diameter increasing before each individual
14-inch (35.56 cm) minimum for gas dryers or electric dryers, or 16-inch (40.64 cm) minimum for steam
dryers (duct is added).
IMPORTANT:
The dryer
is not
provided with a back draft damper. When exhausted into
a multiple (common) exhaust line, a back draft damper
must be
installed at each dryer
duct.
IMPORTANT:
No more than four (4) dryers
should be
connected to one (1) main common duct.
Summary of Contents for ML-130 II
Page 59: ...ADC 113314 1 06 21 01 25 ...
