Slot Diffuser - GELEC (HK)

2/1/EN/3
Slot Diffuser
Type VSD15
with 15 mm wide diffuser face

Contents
Air Diffuser Discharge Characteristics (horizontal) 2
Description 3
Air Diffuser Discharge Characteristics (alternating) 3
Construction · Dimensions 4
Materials 4
Installation of Dummy Sections 5
Installation · Assembly 6
Nomenclature 8
Acoustic Data 8
Spectral Data 8
Aerodynamic Data 9
Order Details 12
Air discharge
horizontal, right
Air discharge
horizontal, left
2

Description
The type VSD15 slot diffuser is ideal for use where
suspended ceiling panels leave narrow gaps just 16 mm
wide. As air diffusers should be invisible with this type of
ceiling design, the slot diffusers are supplied as standard in
black (RAL 9005). An anodised finish is required on VSD15,
construction Z0 can be supplied natural anodised to
E6-C-0. The type VSD15 can be used in rooms with
heights from approx. 2.60 m to 4.00 m. These diffusers are
characterised by high induction, which results in rapid
decay of supply air velocity and temperature differential.
The recommended volume flow range is 8 to 25 l/s/m with a
supply air temperature difference of up to ± 10 K. Because
of their stable discharge characteristics, slot diffusers are
suitable for use in systems with constant or variable volume
air flows.
The direction of air discharge can be adapted to the room
conditions required. The air control blades are set as
specified on the order. If the discharge direction has to be
subsequently changed, this can easily be done by rotating
the air control blades on site.
Air discharge
alternating, angled
Air discharge
alternating, horizontal
200
100
3

Construction · Dimensions · Materials
Construction · Dimensions
The diffuser is supplied with the rear-mounted plenum box,
which, if required, can be fitted with internal acoustic lining.
The plenum has circular side entry spigot into which can, if
required, be fitted volume control damper which can be
adjusted from the diffuser face. When used in continuous
linear format dummy sections can be fitted between or at
the end of active sections (see page 5).
The integral border, Z0, can be supplied for constructions
A, F and D versions. Dummy sections are not available
in Z0.
Materials
The diffuser face consists of aluminium extruded section.
The visible surfaces of VSD15 are black (RAL 9005),
powder coated.
Visible surfaces of VSD15-Z0 natural anodised (E6-C-0).
The plenum box is of galvanised sheet steel.
Lining of mineral wool.
70
40 L 1 -4
58
182
78
15
VSD15-A-M
40
VSD15-A-M-Z0
L 1
202
110 40
78
Length L 1
(mm)
600
700
800
900
1000
1100
1200
1300
1400
1500
End angle only for construction Z0
14 L 1
L 1
58
Without end angle
End angle right
15
VSD15-D-M
40
VSD15-D-M-Z0
End angle left
End angle both ends
4

Installation of Dummy Sections
Fig. 1
Two special air control blades are pushed in to the ends of
the dummy section. The assembled unit is then pressed from
below into the slot diffusers which are already suspended in
position. For lengths L 1 > 1000 mm, a central installation
subframe must also be fitted (see Fig. 3).
Fig. 2
If a dummy section terminates at a wall on one side, a
bracket fixing such as that shown must be provided by
the customer. The other side can be mounted as shown
in Fig. 1.
Fig. 3
Separate mounting of dummy sections by installation
subframes. The screw is supplied and its head is pushed
into the dummy section, and the entire unit suspended
and aligned with the installation subframes. Up to length
L 1 = 1500 mm, two installation subframes are required.
Fig. 1
Slot Diffuser
Dummy Section
Special air control blade
Fig. 2
supplied by others
Dummy section
Fig. 3
Installation subframe (30 mm wide)
Ceiling panels
supplied by others
30
100
127
5

Installation · Assembly
Fig. 4
Slot diffusers of type VSD15 are also suitable for mounting
onto the sides of light troffers. The method of fixing and
components required must be agreed. All necessary
provisions/components will then be supplied by Trox, i.e.
inserts, clamping angles etc. Fig. 4 shows an example with
clamping angle and threaded insert.
Fig. 5
Standard installation of slot diffusers using 4 suspension
brackets fitted to the plenum box. Suitable installation and
fixing accessories supplied by others.
Fig. 6
When slot diffusers are to be installed in panelled ceilings
with external radius R 10 mm, they can be mounted up
to 7 mm above the ceiling line. If the ceiling panels are
rectangular however, the profile edge of the slot diffuser
must lie flush with the ceiling line, i.e. the air control blade
projects approx. 1 mm.
Fig. 7
When slot diffusers are installed in plaster board ceilings
the diffuser can be supplied with integral border Z0 for
covering the cut opening.
Fig. 4 Fig. 6
max. 7
Light
R 10
min. 1
Threaded
insert
Clamping
angle
Fig. 7
Fig. 5
6

Installation · Assembly
Fig. 8
When slot diffusers are fitted in a linear format, connecting
pins are used to align the front face. The connecting pins
(2 per section) are first inserted into one section and then
pushed halfway into the other section.
Fig. 9
For an airtight seal on the first and last diffuser in a linear
format, an end seal must be fitted. This can be installed in
the factory or on site by others. When diffusers are installed
as single units, a seal at both ends must be used.
The end seal is not available for type Z0.
Fig. 10
The air flow rate can be adjusted from the diffuser face.
The air control blade under the spigot should be rotated
until the damper can be adjusted by a screwdriver or rod
(max. 3.5 mm, approx. 100 mm long). The control blade
can then be reset.
Fig. 8 Fig. 10
1
2
1 Connecting pin
2 Flat bar max. 1.5 mm thickness
Fig. 9
2
1
1 End seal (tube)
2 Intermediate seal
7

Nomenclature · Acoustic Data · Spectral Data
Nomenclature
V . in l/s · m: Volume flow per unit length
V . in m 3 /h · m: Volume flow per unit length
V . t in l/s: Total volume flow
V . t in m 3 /h: Total volume flow
A in m: Spacing between two diffusers
H 1 in m: Distance between ceiling and occupied zone
H 1 max in m: Max. penetration depth when heating
L in m: Distance from diffuser L = A/2 + H 1
or L = X + H 1
v–
H1 in m/s: Time average air velocity between two
diffusers at distance H 1 from the ceiling
v–
L in m/s: Time average air velocity at the wall at
distance L
v eff in m/s: Effective jet velocity
in m: Effective width of slot
s eff
t Z
t L
in K: Temperature difference between supply air
and room air
in K: Difference between core temperature and
room temperature at distance L
p t in Pa: Total pressure drop
L WA in dB(A): A-weighted sound power level
L WNC : NC rating of sound power level
L WNR : L WNR = L WNC +3
L pA , L pNC : A-weighting and NC rating of room sound
pressure level
L pA ≈ L WA – 8 dB
L pNC ≈ L WNC – 8 dB
L in dB/Oct.: Relative sound power level with respect
to L WA
L W in dB/Oct.: Octave band sound power level of
regenerated noise L W = L WA + L
in °: Damper angle
1 Sound power level and pressure drop (supply air)
Pressure drop p t in Pa
V . t
300
200
150
100
80
60
40
30
20
15
Relative Spectra L for damper angle = 0°
Length
L WNC 15 20 25 30 35 40 45 50
Effective
jet velocity
Length 600 1000 1500
20 25 30 35 40 45 50 55
L WA in dB(A)
10
8
7 10 l/s 15 20 30 40 50 60 70 80
30 m 3 /h 60 80 100 150 200
Correction to Diagram 1:
Air control damper
Correction to Diagram 1:
Extract air
Octave Band Centre Frequency
Hz
°
Damper angle 0° 45° 90°
L 1 = 600 p t x 1.0 x 1.15 x 1.3
L 1 = 1000 p t x 1.0 x 1.15 x 1.7
L 1 = 1500 p t x 1.0 x 1.25 x 2.0
L 1 L WA p t
600 – 10 x 0.20
1000 – 10 x 0.22
1500 – 10 x 0.41
mm
v eff
m/s
63 125 250 500 1000 2000 4000 8000
600 + 7 + 4 + 8 – 7 – 22 – 24 – 32 – 34
1000 3 + 12 + 3 + 8 – 7 – 22 – 23 – 31 – 34
1500 + 9 + 6 + 7 – 6 – 20 – 24 – 33 – 42
600 + 2 + 2 + 7 – 3 – 14 – 16 – 24 – 26
1000 5 + 8 + 1 + 6 – 3 – 14 – 15 – 24 – 27
1500 + 5 + 4 + 6 – 2 – 12 – 16 – 25 – 34
600 – 2 0 + 5 – 2 – 9 – 12 – 20 – 22
1000 7 + 4 – 2 + 4 – 1 – 10 – 11 – 20 – 23
1500 0 + 1 + 4 – 1 – 9 – 13 – 21 – 30
600 – 4 – 2 + 4 – 1 – 8 – 10 – 19 – 21
1000 8 + 2 – 3 + 3 – 1 – 9 – 10 – 19 – 22
1500 – 2 – 1 + 3 0 – 7 – 11 – 20 – 29
For calculation of v eff see page 9.
8

Aerodynamic Data
Air discharge: horizontal one direction
Example
Data given:
VSD15
Slot length
Total volume flow
L 1 = 1000 mm
V . t = 15 l/s
Required: Octave band sound power level for regenerated
noise L W
Octave band
centre frequency
in Hz
L WA
in dB(A)
L
in dB
L W
in dB
63
24
+ 10
34
125
24
+ 2
26
250
24
+ 7
31
500
24
– 5
19
1000
24
– 18
6
2000
24
– 19
5
4000
24
– 28
– 4
8000
24
– 31
– 7
Diagram 1:
L WA = 24 dB(A)
p t = 18 Pa
Sound power level and pressure drop
Effective jet velocity v eff :
V . t
15
v eff = = = 3.75 m/s
s eff ·L 1 · 1000 0.004 · 1 · 1000
Effective width of slot
Air discharge horizontal angled
s eff in m 0.004
2 Air velocity between two diffusers
and at the wall
H 1 = 1.0 1.2 1.6 2.0 m
Diffuser Layout
A
L
X
l/s · m (m 3 /h · m)
V . = 20 (72)
0.80
L
v–
H1 in m/s
0.50
0.40
0.30
0.20
10 (36)
8 (29)
15 (54)
0.60
0.50
0.40
0.30
v L in m/s
H 1
t – L
v L
v–
H1
t L
0.15
0.20
0.10
1.0 1.5 2.0 3.0 4.0 6.0 m
Spacing A or Distance L
3 Temperature Quotient
0.30
Effective
jet velocity
Temperature Quotient t L /t Z
0.20
0.15
0.10
0.07
V . t in l/s
V . t
v t eff =
= [m/s]
s eff ·L 1 · 1000
V . t in m 3 /h
V . t
v t eff =
= [m/s]
s eff ·L 1 · 3600
s eff
L 1
= 0.004 m
= length of slot diffuser
in m
0.05
1.0 2.0 3.0 4.0 5.0 6.0 m
Distance L
9

Aerodynamic Data
Air discharge: alternating, horizontal
Example
Data given:
VSD15; air discharge horizontal, alternating
Slot length
Volume flow per unit length
Supply air temperature differential
horizontal for cooling
Spacing between diffusers
Distance between ceiling
and occupied zone
Distance between diffuser centre
line and wall
L 1 = 1000 mm
.
V = 15 l/s · m
t Z = – 10 K
A = 2.0 m
H 1 = 1.0 m
X = 2.4 m
Diagram 4:
v–
H1 = 0.12 m/s
Diagram 5:
L = A/2 + H 1 = 1.0 + 1.0 = 2.0 m
t L /t Z = 0.09
t L = 0.09 · (– 10) = – 0.9 K
Diagram 6:
L = X + H 1 = 2.4 + 1.0 = 3.4 m
v–
L = 0.21 m/s
Air velocity between the two diffusers
Temperature Quotient
Air velocity at the wall
Diagram 1: Sound power level and pressure drop
L WA = 24 dB(A) (L WNC = 18 NC)
p t = 18 Pa
4 Air velocity between
two diffusers
H 1 = 1.0 1.2 1.6 2.0 m
Diffuser Layout
A
L
X
0.25
0.20
l/s · m (m 3 /h · m)
V . = 20 (72)
L
15 (54)
0.15
H 1
v–
H1 in m/s
0.10
v–
H1
t L
v – L
t L
10 (36)
200
8 (29)
0.05
1.0 1.5 2.0 3.0 4.0 6.0 m
Spacing A
5 Temperature Quotient 6 Air velocity at wall
0.30
0.50
l/s · m (m 3 /h · m)
V . = 20 (72)
0.40
0.20
Temperature Quotient t L /t Z
0.15
0.10
0.07
v–
L in m/s
0.30
0.20
0.15
10 (36)
8 (29)
15 (54)
0.05
1.0 2.0 3.0 4.0 5.0 6.0 m
Distance L
0.11
1.0 2.0 3.0 4.0 5.0 6.0 m
Distance L
10

Aerodynamic Data
Air discharge: alternating, angled
Example
Data given:
VSD15; air discharge alternating, angled
Slot length
Volume flow per unit length
Supply air temperature differential
Spacing between diffusers
Distance between ceiling
and occupied zone
L 1 = 1000 mm
.
V = 15 l/s · m
t Z = – 8 K
or + 8 K
A = 2.4 m
H 1 =1.2 m
Diagram 7:
v–
H1 = 0.19 m/s
Air velocity between the two diffusers
Diagram 8:
Temperature quotient for cooling
t H1 /t Z = 0.042
t H1 = 0.042 · (– 8) = – 0.336 K
for heating t z = + 8 K
Diagram 1: Sound power level and pressure drop
L WA = 24 dB(A) (L WNC = 18 NC)
p t = 18 Pa
Diagram 9:
H 1max ≈ 1.3 m
Maximal penetration depth when heating
7 Air velocity
H 1 = 1.0 1.2 1.6 2.0 m
Diffuser Layout
A
0.40
l/s · m (m 3 /h · m)
V . = 20 (72)
0.30
15 (54)
H 1
H 1max
v–
H1 in m/s
0.20
0.15
10 (36)
8 (29)
100
v–
H1
t H1
100
0.10
1.0 1.5 2.0 3.0 4.0 m
Spacing A
8 Temperature quotient when cooling 9 Max. penetration depth when heating
0.060
2.5
0.050
2.0
0.040
1.5
+ 4 K
Temperature Quotient t H1 /t Z
0.030
0.025
0.020
H 1max in m
1.0
0.7
t Z = + 8 K
+ 12 K
0.015
0.8 1.0 1.5 2.0 3.0 m
Distance H 1
V .
0.5
5 6 7 8 9 10 l/s · m 15 20 25
20 25 30 m 3 /h · m 50 60 80
11

Order Details
Specification Text
Adjustable slot diffusers with face width of 15 mm, suitable
for installation in between ceiling panels. Consists of diffuser
face with air control blades to provide adjustable discharge
direction. Blades are factory set but are adjustable on site
by others. Available with integral border type Z0. Complete
with a rear mounted plenum box fitted with circular side
entry spigot and four suspension brackets. Optionally, with
20 mm thick internal lining with glass fibre scrim covering
and/or volume control damper adjustable from diffuser face.
Dummy sections available for VSD15 without Z0.
Materials:
VSD15 diffuser face in extruded aluminium section, visible
surface type powder coated black (RAL 9005), or anodised
to European Standard E6-C-0 to C-35.
VSD15 Z0 diffuser face in of extruded aluminium section.
Visible surface natural anodised to E6-C-0 or to European
Standard E6-C-31 to C-35. Air control blades in ABS
(flame retardant), self extinguishing – tested to UL for lack
of molten droplets. Black as standard, white if required
(similar to RAL 9010). Rear plenum box of galvanised sheet
steel, mineral wool lining.
Order Code
VSD15 - A - M - Z0 / 900 / A9 /
Need not be completed for standard products
0 / P1 / RAL 9016 / WS
Plenum box
Plenum box with
lining
Dummy section 2)
Face Section
Volume control
damper M 1)
Integral border Z0
c
v
u
v
b
A
D
B
F
c
v
u
v
b
600
700
800
900
1000
1100
1200
1300
1400
1500
L 1 (mm)
c
v
u
v
b
State
colour
1)
HL Horizontal left
HR Horizontal right
WH Alternating
Horizontal (standard
construction)
WS Alternating
angled
0 standard finish
VSD15 black RAL 9005
VSD15-Z0 E6-C-0
P1 Powder coated to RAL …
S2 Anodised to European Standard
E6-C-0 to C-35
(VSD15-Z0 only E6-C-31 to C-35)
Design changes reserved · All rights reserved © Gebrüder Trox GmbH (08/2000)
Accessories
SE Special air control blades
MT Installation sub frame
1) Not available for type VSD15-B!
Please order accessories SE and MT separately.
2) Dummy sections not available for Z0 construction.
3) End angle only for Z0 construction.
Order code for end angle-pairs supplied loose
– please order separately –
End angle
VSD15-Z0-EW
Accessories:
Special air control blades for mounting dummy sections
on slot diffusers.
Installation subframe for suspending dummy sections.
1)
v
b
c
v
u
0 Not
used
Note!
Black air control blades standard.
If required state “Air control blades white
(similar RAL 9010).
Does not apply to VSD15-B.
0 Without end seals
A9 End seal both ends
c
B9 End seal right end v
u
Looking at plenum spigot
v
C9 End seal left end b
See table for end angle – mounting 3)
End angle – mounting
For
both
construction right left ends
Z0 AA BA CA
Order Example
Make: TROX
Type: VSD15 -A- M / 900 / A9 / 0 / P1 / RAL 9016 / WS
Air control blades white
Accessories: SE/MT
12