User guide

Tips about the ductwork
Check with your local building code
to determine the maximum allowable
duct length.
Only use rigid or flexible metal duct
for exhausting. Non-metallic flexible
hose should not be used, it is a
potential fire hazard.
Rigid metal or flexible aluminum
ducting is preferred. Flexible foil
ducting may move and bounce due
to the high airflow of the dryer. This
could lead to a thumping or grinding
noise.
Non-metallic flexible hose should not
be used. It is a potential fire hazard.
In the United Stated foil-type flexible
ducts should only be used if
identified for use by the manufacturer
as compliant with the Outline for
Clothes Dryer Transition Duct,
Subject ANSI/UL 2158A.
In Canada, only flexible metal
(foil-type) ducts specifically identified
for use by the manufacturer should
be used.
For best drying results avoid extra
long ducting with too many bends,
angles or tight corners.
Do not assemble the duct with
screws or other fastening devices
that extend into the duct and catch
lint.
The shorter the exhaust ductwork,
the more efficient the dryer will be.
Expelled air is slowed down in the
ducts due to friction against the inner
walls. The shorter and smoother the
inner walls are, the less friction will
be created.
An elbow or bend creates more
friction than a straight duct. An
additional duct length factor must be
added for each elbow or bend (see
Table). This factor expresses the
resistance of the bend in terms of a
straight length of duct.
The additional length factor is then
added to the existing duct to give the
effective duct length.
A larger duct diameter helps to
reduce friction. Therefore duct
diameter should be increased if
longer duct lengths are required.
Ducting
20