Selection procedure – Trane Fan User Manual
Page 21
21
Selection
Procedure
Q-Fan Sound Power By Octave Band At Nominal Cfm/SP
Fan Size
63 Hz
125 HZ
250 Hz
500 Hz
1000 Hz
2000 Hz
4000 Hz
8000 Hz
16
2
3
10
16
19
20
13
12
19
2
3
10
16
19
19
13
12
21
2
4
10
16
19
19
13
11
24
3
4
10
16
19
19
13
10
27
3
5
10
16
19
19
13
9
30
4
5
10
16
19
17
13
9
36
4
6
10
16
19
15
13
9
40
5
6
11
16
19
14
12
9
44
5
6
11
16
19
14
11
9
Table S-2 — Long Plus Silencer Attenuation (2D Length)*
Q-Fan Sound Power By Octave Band At Nominal Cfm/SP
Fan Size
63 Hz
125 HZ
250 Hz
500 Hz
1000 Hz
2000 Hz
4000 Hz
8000 Hz
16
3
6
19
32
37
39
26
24
19
3
6
19
32
37
37
26
24
21
4
7
19
32
37
37
26
22
24
5
8
19
32
37
37
26
20
27
6
9
19
32
37
37
26
18
30
7
9
20
32
37
34
26
18
36
8
11 20
32
37
30
25
18
40
9
11 21
32
37
28
23
18
44
9
12 21
32
37
28
22
18
*Approximate attenuations. Use the Trane Fan Selection Program for attenuation predictions that include silencer
regenerated self-noise.
NOTE: Super Q II not available with Class III fans.
9
If inlet vane modulation was selected,
increase the rpm by 1 percent and
increase the bhp by 3 percent.
10
If the air density ratio is nonstandard
(different than 1.00), the rpm is correct
and the bhp must be multiplied by the
air density ratio.
11
If the start-up air temperature is lower
than the normal operating
temperature, adjust the fan curve bhp
for the starting temperature. The next
larger nominal hp motor is the correct
motor size.
12
If exceptional quiet is desired, choose a
short or long Q fan plus duct silencer.
The plus silencer is a low turbulence,
low pressure drop, high attenuation
duct silencer. Subtract the attenuations
given in Tables S-1 and S-2 from the
Q fan/Super Q II fan sound power
projections. If silencer regenerated
noise is a concern, contact your local
Trane sales engineer for further
information.
Table S-1 — Short Plus Silencer Attenuation (1D Length)*
7
Input the selection parameters into the
Trane fan selection program and select
the desired Q fan or proceed with a
manual selection.
8
Manual Selection:
a
Determine the air density ratio if non-
standard air is being handled by the
Q fan.
b
Adjust the external sp by the air density
ratio.
c
Use the inlet and outlet area of the fan
to calculate the inlet and outlet
velocities. Use these velocities and the
inlet and outlet Kt to correct the
external static pressure to the right
value. Reselect the fan at the right
value.
d
From the performance table, select the
desired fan.
1
Select the type of fan desired. The
Super Q II should be used where fan
radiation noise needs to be attenuated.
2
Position the Q fan to deliver air to the
system and minimize adverse Kt effects.
Straight-thru flow arrangements are
best.
3
Select the desired Q fan or Super Q II
fan options.
4
Compute the fan external static pressure
and cfm requirements.
5
Determine which Kt effects apply to the
Q fan installation.
6
If the Q fan is serving a VAV system,
select AC frequency drive or inlet vane
modulations. (AC frequency drive
modulation is considerably quieter and
more efficient than Q fan inlet vanes.)
Super Q II fans use AC frequency drive
modulation only.