6
Dryer Enclosure Requirements
___
Bulkheads and partitions should be made of
noncombustible material.
A. The requirement to allow the dryer door to open completely
is 29" (74 cm).
B. A minimum overhead clearance of 12" (30.48 cm) is
required.
C. Dryer should be positioned a minimum of 12" (30.48 cm)
away from the nearest obstruction. 24" (60.96 cm) is
recommended for ease of installation, maintenance, and
service.
D. 1/16" (1.5875 cm) minimum is required.
E. Flooring should be level or below dryer cabinet for ease of
removing panels during maintenance.
F. Dryers may be positioned sidewall to sidewall, however a
1/16" (1.5875 cm) minimum allowance must be made for
the opening and closing of the control door, along with the
removal of panels during maintenance.
G. 4" (10.16 cm) maximum.
Fresh Air Supply Requirements __
When the dryer is operating, it draws in room air, heats it,
passes this air through the 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. Fresh air
ventilation openings shall not be blocked and/or sealed. As
a general rule, an unrestricted air entrance from the outdoors
of 1.0 ft
2
(0.093 m
2
) is required for each dryer. (Based on 1 inch
2
[6.5 cm
2
] per 1,000 Btu [252 kcal].)
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 four dryers, 2 unrestricted openings
measuring 12" by 24" (30.48 cm by 60.96 cm) are acceptable.
To compensate for the use of registers or louvers used over the
openings, this area must be increased by approximately 33%.
Make-up air openings should not be located in an area directly
near where exhaust vents exit the building.
Allowances must be made for remote or constricting
passageways or where dryers are located at high
altitudes or predominantly low pressure areas.
IMPORTANT:
Make-up air must be 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.
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, and shutdown of the burner by the
airflow (sail) switch, burner hi-limits, or lint chamber hi-limit
protector thermostat. The dryer must be installed with a proper
exhaust duct connection to the outside.
As per the National Fuel Gas Code, “Exhaust ducts for type
2 clothes dryers shall be constructed of sheet metal or other
noncombustible material. Such ducts shall be equivalent in
strength and corrosion resistance to ducts made of galvanized
sheet steel not less than 26 gauge (0.0195" [0.50 mm]) thick.”
D
F
A
B
E
C
G
MAKE-UP AIR OPENINGS
A=12
"
(30.48 cm)
B=24
"
(60.96 cm)
A
B
B
A
