Milnor 7272TG1L, Installation And Service

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How to Size Inlet and Discharge Air Ducting
PELLERIN MILNOR CORPORATION
Pressure Drop (P.D.)= Length of Straight Duct/100 X Loss per 100'
(from table)
+ Number of short elbows X loss (from table).
+ Number of long elbows X loss (from table).
+ Maximum back pressure from lint collector.
Example (see Figure 2)
Pressure drop (P. D.) = 0.25 + 0.03 + 0.06 + 0.03 +0.18 + 0.05 +
0.25 = 0.85
Note 2: Ensure adequate duct size by always rounding up each segment's calculated Pressure drop (P. D.)
as necessary. Example: Round up 0.024 to 0.03.
Figure 2: Duct Layout Example (64058TG1 shown)
Duct example Legend
.
A. Vertical inlet duct 24"x
16" x 25' + (1) 90° elbow
(R = 23") P. D.(Pressure
drop) = (25/100) x 0.683
+ .08 = 0.25
B. Exhaust duct 26" diameter
P. D.(Pressure drop ) =
(10/100) x 0.3 = 0.03
C. Smooth round long elbow
P. D.(Pressure drop) =
0.06
D. Straight duct P.
D.(Pressure drop) =
(8/100) x 0.3 = 0.03
E. 3 Pc Round short elbow P.
D.(Pressure drop) = 0.18
F. Transition is considered
straight P. D.(Pressure
drop) = (15/100) x 0.3 =
0.05
G. Lint collector - Max
allowable P. D.(Pressure
drop) = 0.25
— End of BIPDGI01 —
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