Ceiling diffusers

Ceiling diffusers
4
SPK- square diffusers
4-way square diffuser for ceiling mounting
made of white lacquered steel (RAL 9010).
The diffuser is equipped with a removable
core.
Application
As air supply and return air grille
in ventilation, air conditioning
and heating systems.
Fixation
Fixation by means of a screw in
the plenum box.
Options
D: Volume control damper with
counter-revolving blades.
RES: Plenum box with lateral
connection.
In option: insulated plenum box
is available.
© ATC
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Dimensions
Type A x A L x L B x B C x C
(mm) (mm) (mm) (mm)
288 294 147 144 222
363 369 222 219 297
438 444 297 294 372
513 519 372 369 447
595 594 447 444 522
663 669 522 519 597
738 744 597 741 672
Aticle number: SPK-4 : A04 031 1 xxx 000
(xxx = type of diffuser)
SPK-4
L x L
B x B
C x C
A x A
Options
SPK-4 + D
L x L
B x B
D: Volume control damper with counter-revolving blades. The
volume control damper is supplied separately and is mounted
on the diffuser by means of clips. Settings are done by means
of a screwdriver after taking out the diffuser core.
Article number: A04 031 2 xxx 000 (xxx = type of diffuser)
RES: Plenum box with lateral connection. Available with or
without insulation.
RES
C x C
A x A
© ATC

Technical data
Complementary information to the selection table (see back page)
• Q = air flow rate in m 3 /h.
• Veff = effective air velocity between the blades of
the diffuser in m/s.
• L0,25 = throw in m at a terminal velocity of
0,25m/s.
• ∆Pt = total pressure loss in Pa.
• NR = sound level.
• Throw correction factor for the distance between
the diffuser and the ceiling (Ch).
For adherent jets, i.e. diffuser aligned with the
ceiling, Ch = 1.
For free jets, with the diffuser separated from the
ceiling, Ch = 1,4.
• The selection table is based on laboratory tests
according to standards ISO 5219, ISO 5135 and ISO
3741.
• The diffuser is aligned with the ceiling.
• The diffuser was placed in the centre of a square
test room.
• The height of the room is 3 +/- 0,5m.
• The temperature difference between the supply
air and the room temperature is -10°C
• The NR values are based on the sound power
level without room attenuation and without
volume control damper.
The corrected throw then is: Lc = L0,25 x Ch.
• Correction factor when using a volume control
damper (D).
The volume control damper modifies the values of
the sound level and pressure loss given in the selection
tables in function of the percentage opening of
the volume control damper. The correction factors
are indicated in the following table:
Opening 100% 50% 25%
∆P X 1,5 X 2,5 X 4,5
∆NR + 0 dB + 4 dB + 10 dB
Some additional information:
• To obtain an adherent jet with cold air, it is
advisable not to exceed the maximum distance
between the diffuser and the ceiling (h. max.) in
function of the temperature difference (∆t) (difference
between room and supply air temperature)
indicated in the following table:
∆t (°C) 0 6 9 12
h max (m) 0,2 0,1 0,07 0,05
© ATC
• Minimum recommended velocity in the occupied
zone, Vz:
Due to the difference in temperature (∆t)
between air in the room and the cold supply air,
the following minimum velocities Vz are recommended
in the occupied zone:
∆t (°C) 0 6 9 12
Vz (m/s) 0,15 0,15 0,2 0,25

Selection table
Legend
Q = air flow rate in m 3 /h
Veff = effective air velocity between the blades
of the diffuser in m/s
L0,25 = throw in m at a terminal velocity of 0,25 m/s.
∆P = total pressure loss in Pa
NR = sound level
∆T=10°C Type 288 363 438 513 595 663 738
Q Ak (m 2 ) 0,0102 0,0229 0,0408 0,0637 0,0917 0,1249 0,1631
(m 3 /h)
100 Vk (m/s) 2,72 1,21
L0,25 (m) 1,00 0,70
∆P (Pa) 3,30 0,60
NR 22 5
150 Vk (m/s) 4,08 1,82 1,02
L0,25 (m) 1,60 1,80 0,75
∆P (Pa) 7,40 1,50 0,45
NR 33 15 3
200 Vk (m/s) 5,45 2,43 1,36
L0,25 (m) 2,10 1,40 1,00
∆P (Pa) 13,10 2,60 0,80
NR 41 23 10
300 Vk (m/s) 8,17 3,64 2,04 1,31
L0,25 (m) 3,10 2,10 1,60 1,20
∆P (Pa) 29,40 5,80 1,80 0,80
NR 51 33 21 11
400 Vk (m/s) 4,85 2,72 1,74 1,21
L0,25 (m) 2,80 2,10 1,70 1,40
∆P (Pa) 10,40 3,30 1,30 0,60
NR 41 28 19 11
500 Vk (m/s) 6,07 3,40 2,18 1,51 1,11
L0,25 (m) 3,50 2,60 2,10 1,70 1,50
∆P (Pa) 16,20 5,10 2,10 1,00 0,50
NR 47 34 24 16 10
700 Vk (m/s) 8,49 4,77 3,05 2,12 1,56 1,19
L0,25 (m) 4,80 3,60 2,90 2,40 2,10 1,80
∆P (Pa) 31,70 10,00 4,10 2,00 1,10 0,60
NR 56 43 33 25 18 13
1000 Vk (m/s) 6,81 4,36 3,03 2,22 1,70
L0,25 (m) 5,20 4,10 3,50 3,00 2,60
∆P (Pa) 20,40 8,40 4,00 2,20 1,30
NR 52 43 35 28 22
1500 Vk (m/s) 6,54 4,54 3,34 2,55
L0,25 (m) 6,20 5,15 4,40 3,85
∆P (Pa) 19,00 9,05 4,85 2,90
NR 53 41 39 33
2000 Vk (m/s) 8,72 6,06 4,45 3,41
L0,25 (m) 8,30 6,90 5,90 5,20
∆P (Pa) 33,50 16,10 8,70 5,10
NR 61 53 46 40
2500 Vk (m/s) 7,57 5,56 4,26
L0,25 8,60 7,40 6,50
∆P (Pa) 25,20 13,60 8,00
NR 59 52 46
3000 Vk (m/s) 6,67 5,11
L0,25 (m) 8,90 7,80
∆P (Pa) 19,60 11,50
NR 57 51
4000 Vk (m/s) 8,90 6,81
L0,25 (m) 11,80 10,40
∆P (Pa) 34,80 20,40
NR 64 58
Models can be subject to construction changes.
© ATC
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