Rotary diffuser NSRA TECHNICAL DATA - 2010 page 129
Rotary diffuser NSRA
Rotary diffuser NSRA is suitable for public premises such as offices,
hotels etc. and for those places where high inductivity diffusers might be
using. Air supplied through NSRA diffuser can be easily mixed up with air
inside the room.
Intensification of mixing with indoor air results that the primary airflow
with initial large temperature difference may be supplied into the occupied
zone, assuring people thermal comfort. Because there is no need to supply
large volume of primary air, the devices such as air handling units, heaters,
etc. might be designed in smaller sizes, which causes capital costs decrease.
Diffuser's high inductivity makes it perfect to be used also in low height
rooms.
Diffuser is made from zinc steel sheet, powder painted in RAL palette colors.
Quick selection
NSRA type
Airflow
(m3/h)
Pressure drop
Height above
(Pa)
the floor (m)
one - way
100 – 480
10 – 43
2.5 – 4.2
two - way
160 – 480
10 – 20
2.5 – 4.2
480 – 960
20 – 80
2.5 – 4.2
Fläkt Woods
PLBOV 2010.07
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Product facts
Rotary diffuser NSRA
Intended for wall installation.
One- or two-way spread pattern.
Delivered with or without connection box.
Product code example:
Rotary diffuser NSRA-1-2-1
Dedicated for assembling on ventilation duct, two-way diffusion
pattern.
The diffuser is painted in colour
RAL 9010.
Specifications are subject of alteration without further notice.
Rotary diffuser NSRA TECHNICAL DATA - 2010 page 130
Construction, dimensions
Construction
One way diffuser has an air flow range between
80 m3/h and 480 m3/h
and two way between 160 m3/h and 960 m3/h.
Installation height above the floor is between 2,5 and 4,2m.
Temperature difference depends on heat load of the
room and diffuser’s height above the floor.
Maximum temperature difference for heating: Dtp ≤ 8K,
Maximum temperature difference for cooling: Dtp ≤ 9K
1 –
2 –
3 –
4 –
5 –
6 –
Standard diffuser has a RAL 9010 (white color) finish.
Other colors are available on request. Diffuser might be
installed directly on ventilation duct or by using a plenum
box. Connection box is made from zinc steel sheet with
or without acoustical insulation. There are handles on the
box that enable hanging it under the ceiling. Manual
damper placed on the connection duct controls the airflow.
casing
air supply holes (single or double sides)
connection box
connection duct
manual damper
ventilation duct
Dimensions
Diffuser assembled directly on distribution duct
NSRA type
A (mm)
B (mm)
C (mm)
E (mm)
D (mm)
L (mm)
one - way
380
270
260
82
223
1000
two - way
380
270
260
82
223
1000
18.0
380
270
260
82
2x223
1000
(diffuser with connection box)
Fläkt Woods
PLBOV 2010.07
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Weight (kg)
Specifications are subject of alteration without further notice.
Rotary diffuser NSRA TECHNICAL DATA - 2010 page 131
Examples of positioning, selection of diffusers
4.
5
4.
0
Throw length
3.
5
3.
0
2.
5
Examples of diffusers positioning in room
Throw length L
per one side
Throw length L
One - way diffuser placed on the opposite wall of the
room.
per one side
one- and two - way diffuser
two - way diffuser
Throw length L
ffu
se
r
Two - way diffuser placed on ceiling in the middle of the
room.
di
ffu
se
r
ay
-w
tw
o
-w
ay
di
on
e
Throw length L
Example:
Total airflow
Height above the floor
Room width
Required throw length
Airflow per diffuser
Number of diffusers
Pressure drop Dp
Vc = 18000 m3/h
H = 3,6 m
12 m
L=6m
One-way diffuser.
Two - way
560 m3/h
i=
18000
560
= 32
26 Pa
Diffusers place along
the centre line of room
Fläkt Woods
Throw length L
PLBOV 2010.07
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Throw length L
One - way diffuser placed on corridor in the false ceiling.
Specifications are subject of alteration without further notice.
Rotary diffuser NSRA TECHNICAL DATA - 2010 page 132
Acoustic data, descriptive text, product code
Diffusers with uninsulated plenum box
Attenuation
One - way diffuser
Uninsulated connection box
Airflow
Pressure
Acoustic power level LW (dB)
drop
for octave bands, (Hz)
Octave bands, (Hz)
125
250
500
1000
2000
1
10
8
12
17
(m3/h)
(Pa)
LWA(dB)
125
250
500
1000
2000
120
6
21
18
-
-
-
-
180
8
22
19
-
-
-
-
240
10
23
19
16
-
-
-
300
16
28
35
28
25
20
-
125
250
500
1000
2000
360
24
30
39
29
26
22
21
2
11
10
20
24
420
32
35
42
33
31
26
23
Two - way diffuser
Airflow
Acoustic power level LW (dB)
drop
for octave bands, (Hz)
Rotary diffuser NSRA for wall installation manu­fac­tured
by Fläkt Woods.
(Pa)
LWA(dB)
125
250
500
1000
2000
400
13
25
38
23
19
-
-
500
21
31
43
29
25
23
-
600
30
36
47
38
32
30
26
700
43
39
50
40
35
31
28
800
55
45
54
44
39
37
30
900
70
48
58
49
42
40
35
Diffusers with insulated plenum box
Pressure
Acoustic power level LW (dB)
drop
for octave bands, mean frequency (Hz)
(m3/h)
(Pa)
LWA(dB)
125
250
500
1000
2000
120
6
20
16
-
-
-
-
180
8
21
17
-
-
-
-
240
10
22
17
15
-
-
-
300
16
26
34
26
24
19
-
360
24
29
38
28
25
21
20
420
32
33
41
32
29
22
22
Two - way diffuser
Pressure
Acoustic power level LW (dB)
drop
for octave bands, mean frequency (Hz)
(m3/h)
(Pa)
LWA(dB)
125
250
500
400
13
24
37
23
500
21
30
42
28
600
30
34
45
700
43
38
800
55
43
900
70
47
Product code
Rotary diffuser
NSRA-a-b-c
Installation method
1 = for assembling on ventilation duct
2 = for assembling on connection box
Diffusion pattern
1 = one-way
2 = two-way
One - way diffuser
Airflow
Octave bands, (Hz)
Descriptive text
Pressure
(m3/h)
Airflow
Insulated connection box
1000
2000
18
-
-
24
22
-
36
31
29
25
48
39
33
30
27
53
43
39
36
29
57
48
41
39
34
Colour
1 =standard RAL 9010
X = any other colour from RAL palette
Connection box
NSRS-a-b-c-d
Number of connection ducts
1 = one
2 = two
Position of connection duct
1 = from the rear
2 = at the front
3 = at the right side
4 = at the left side
5 = on the top
Damper
0 = without
1 = manual damper
Type
0 = uninsulated
1 = insulated
Fläkt Woods
PLBOV 2010.07
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Specifications are subject of alteration without further notice.