VAV-107 - page 6

6
*d=1.326 x Pb
°F+460
Pt =Ps +Pv
2
2
*Pv = Q = V
Ax 4005
4005
FanBHP= QxPt
= QxPs
6362 x n t
6362 x ns
For 3phasemotors: BHPoutput =
Ex I xMExPf x 1.73
746
For 3phasemotors: Kw input =
Ex I xPf x 1.73
1000
For 1phasemotors: BHPoutput = Ex I xMExPf
746
For 1phasemotors: Kw input =
Ex I xPf
1000
Toplot aSystemCurvewherePs1andQ1are known, use
the following formula to findother curvepoints:
Ps 2 = Ps1
Q
2
2
Q
1
Todetermine roundduct equivalent of rectangular duct for
same friction loss and volumetric capacity:
DR = 1.265
5
(ab)
3
a+b
* Formulas for dandPv areapplicable todry air only.
(
( ( (
( (
Symbol Definition
A
area (ft.
2
)
a
sideaof rectangular duct
b
sidebof rectangular duct
BHP brakehorsepower
Q air volume flow (ft.
3
/min.)
d
air density (lb/ft.
3
)
DR diameter of roundduct
E
volts
°F
temperature (Fahrenheit)
I
amps
KW kilowatts
ME motor efficiency (dec.)
ns
fan static efficiency (dec.)
n t
fan total efficiency (dec.)
Pb
barometric pressure
(inchesmercury)
Pf
power factor
Ps
static pressure
(inchesWG)
Pt
total pressure (inchesWG)
Pv
velocity pressure
(inchesWG)
V
velocity (ft./min)
Fan Application Formulas
Fan
Sound
Data
Chicago Blower design 47 Vane Axial
Fans have been carefully noise tested in
accordance with AMCA Standard Test
Code No. 300 for sound Rating of Air
Moving Devices. Certified Sound Rating
data is availableupon request.
Sounddata is as completeas it is possi-
ble to provide. It permits the engineer to
compare noise levels accurately with
other fans if they are also accurately
tested and rated according to theAMCA
Code. It permits the engineer to deter-
mine dBA levels quickly without calcula-
tion, and provides the information needed
todeterminedBA levels for specific instal-
lations.
Forapplications requiring lowest noise lev-
els, ChicagoBlower hasattenuatorsavail-
able designed specifically for Design 47
characteristics.VaneAxial fans are easier
and less costly to attenuate thanCentrifu-
gal fans.AnattenuatedDesign47 fan can
provide lowest noise levels at low cost
within thebuildingspace.
1,2,3,4,5 7,8,9,10,11,12,13,14,15,...16
Powered by FlippingBook