Maytag MC2 - Manual (Page 23)

C. EXHAUST REQUIREMENTS
Exhaust duct work should be designed and installed by a competent technician. Improperly sized duct work
will create excessive back pressure which will result in slow drying, increased use of energy, and shutdown
of the burner by the airflow (sail) switch, burner hi-limit or lint chamber hi-heat
protector thermostat. Refer to Figure 7 for details
NO. OF DRYERS 6 5 4 3 2 1
MINIMUM CROSS SECTION
AREA (SO.IN) FOR 12" DIA DUCTS
670 560 450 340 230 115
MINIMUM ROUND DUCT
DIA (IN.) FOR 12" DIA DUCTS
30 28 24 22 18 12
MINIMUM CROSS SECTION
AREA (SO IN.) FOR 16" DIA DUCTS
1230 1025 820 615 410 205
MINIMUM ROUND DUCT
DIA (IN ) FOR 16" DIA DUCTS
40 36 32 28 24 16
2 X D CLEARANCE
k w H r
FIGURE 7
FORMULAS TO CALCULATE DUCTING CROSS SECTIONAL AREA
785 X D WHERE D-DtAMETER
H WHERE W
CROSS SECTIONAL AREA OF A ROUND DUCT
OF DUCT.
CROSS SECTIONAL AREA OF A RECTANGULAR DUCT - W
-WIDTH AND H-HEIGHT,
Where possible, it is desirable to provide a separate exhaust air duct for each dryer. The duct for 100 lb.
dryers should be 12 inches in diameter. The duct should go as directly as possible to the outside air. Avoid
sharp 90 degree right angle turns in the ducting; use 30 degree or 45 degree angles instead. The radius of the
elbows should preferably be 1 -1/2 times the diameter of the duct. To protect the outside end of the duct from
the weather, it may be bent downward as indicated in Figure 7. Leave at least twice the diameter of the duct
clear between the duct opening and the nearest obstruction. If the exhaust duct goes through the roof, it may
be protected from the weather by using a 180 degree turn to point the opening down as indicated in Figure 8.
Allow at least twice the diameter of the duct as clearance from the nearest obstruction as indicated in
Figure 8.
CAUTION: IMPROPERLY SIZED OR INSTALLED EXHAUST DUCT WORK CAN
CREATE A POTENTIAL FIRE HAZARD.
NOTE: When a dryer is exhausted separately, it is recommended that a back draft damper be installed.
NOTE: When 1001b. dryers are exhausted into a common exhaust line, each dryer musí supplied
with a back draft damper.
Do not use screens or caps on the out side opening of the exhaust duct. The ducting 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. Provide inspection doors
for periodic clean-out of lint from the main duct.
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