Tumble Dryer Installation/Operation Maintenance Manual

ManualsBrandsAlliance Laundry Systems ManualsDryer250 C.F.M.

M414545

• Collector Venting

While it is preferable to exhaust tumblers individually

to the outdoors, a main collector duct may be used if it

is sized accordingly. Refer to Figure 5. This

illustration indicates minimum diameters, and should

be increased if the collector length exceeds 20 feet

(6.1 m). The collector duct may be rectangular in cross

section, as long as the area is not reduced. Provisions

should be made for lint removal and cleaning of the

collector duct.

The collector duct must be tapered. Refer to Figure 5.

The individual tumbler ducts must enter the collector

duct at a 45° angle in the direction of airflow. Never

connect a tumbler duct at a 90° angle to the collector

duct. Doing so will cause excessive back pressure,

resulting in poor performance. Never connect two

tumbler exhaust ducts directly across from each

other at the point of entry to the collector duct.

The collector system must be designed so the static

back pressure measured 12 inches (30.5 cm) from the

exhaust thimble does not exceed the maximum

allowable pressure specified on the installation sticker

on the rear of the tumbler. This must be measured with

all tumblers running that are vented into the collector.

MAKE-UP AIR

A tumbler is forced air exhausted and requires provisions

for make-up air to replace the air exhausted by the

tumbler.

IMPORTANT: Do not obstruct the flow of

combustion and ventilation air.

Recommended make-up air opening to the outside is

144 inches

(928 cm

At a minimum, the National Fuel Gas Code requires

tumblers to have at least one square inch (6.5 sq. cm)

of opening for every 1000 BTU/hr. of input rating for

proper combustion.

Example: A tumbler with a rated input of 120,000

BTU/hr. requires 120 square inches of free

opening.

The additional opening recomended by the

manufacturer is required for optimum drying and

reliability.

Protective louvers in the opening to the outdoors can

reduce air movement by approximately 40 percent. The

opening must compensate for the area taken up by the

louvers.

The make-up air openings for a room containing

tumbler(s) and/or gas fired hot water heater or other

gravity vented appliances must be increased sufficiently

to prevent downdrafts in any of the vents when all

tumblers are in operation. Do not locate gravity vented

appliances between tumbler(s) and make-up air

openings. If it is necessary to duct make-up air to the

tumbler(s), increase the area of the duct work by 25

percent to compensate for any restriction in air

movement.