Lindab CHA Semicircular Perforated Diffuser User Manual
- June 4, 2024
- Lindab
Table of Contents
Perforated diffuser – semicircular
CHA

Description
Comdif CHA is a semicircular perforated displacement diffuser for installation against a wall or column. Behind the perforated front plate, CHA is equipped with individually adjustable nozzles, making it possible to alter the geometry of the near zone. The diffuser can be turned and has a circular duct connection (MF measure), so the diffuser can be connected at the top or bottom. The diffuser is suitable for the supply of large volumes of moderately cooled air.
- The diffuser is suitable for the supply of large volumes of air.
- The geometry of the near zone can be adjusted using adjustable nozzles.
- Duct covers, plinths, and wall brackets can be supplied as accessories.
Maintenance
The front plate can be removed from the diffuser, making it possible to clean the nozzles. The visible parts of the diffuser can be wiped with a damp cloth.
Order code

Order – accessories
| Cover: | CHAZ – 0 – size |
|---|---|
| Plinth: | CHAZ – 2 – size |
| Wall bracket: | CHAZ – 3 – size |
Dimension

Size| A
mm| ØD
mm| H
mm| Weight
kg
---|---|---|---|---
1207| 250| 125| 710| 6,50
1607| 300| 160| 710| 7,50
2010| 330| 200| 970| 13,0
2510| 400| 250| 970| 18,0
3115| 520| 315| 1490| 35,0
4020| 630| 400| 2010| 58,0
5020| 730| 500| 2010| 78,0
6320| 830| 630| 2010| 106
Accessories
Can be supplied with duct cover, plinth, and bracket for wall mounting.
Materials and finish
| Diffuser: | Galvanised |
|---|---|
| Nozzles: | Black |
| Front plate: | 1 mm galvanized steel |
| Standard finish: | Powder-coated |
| Standard color: | RAL 9003 or RAL 9010 – white, gloss30 |
The diffuser is available in other colors. Please contact Lindab’s sales department for further information.
Technical data

Recommended maximum volume flow.
The near zone is given at an under-temperature of -3 K to a maximum terminal
velocity of 0.20 m/s.
Conversion to other terminal velocities – see table 1, correction of the near
zone for -3 K and -6 K respectively.
Sound effect level
Sound effect level
Center frequency Hz
Size| 63| 125| 250| 500| 1K| 2K| 4K| 8K
1207| 11| -4| 1| 1| -9| -16| -28| -34
1607| 9| -2| 2| 0| -8| -16| -28| -34
2010| 10| -2| 3| 0| -7| -16| -28| -39
2510| 11| 0| 4| -2| -7| -15| -27| -37
3115| 13| 1| 3| -1| -7| -17| -29| -42
4020| 7| 3| 2| -1| -5| -14| -19| -14
5020| 7| 3| 2| 0| -6| -16| -19| -17
6320| 7| 3| 2| 0| -6| -16| -29| -17
Sound attenuation
Sound attenuation ΔL [dB] including end reflection.
Centre frequency Hz
Size| 63| 125| 250| 500| 1K| 2K| 4K| 8K
1207| 19| 14| 5| 3| 2| 1| 2| 1
1607| 16| 12| 4| 1| 2| 1| 2| 2
2010| 12| 8| 4| 2| 3| 2| 2| 2
2510| 12| 8| 5| 2| 1| 1| 1| 1
3115| 11| 8| 3| 2| 1| 1| 2| 2
4020| 9| 6| 1| 1| 1| 1| 1| 1
5020| 7| 5| 0| 1| 1| 1| 1| 2
6320| 5| 3| 1| 1| 0| 0| 0| 0
Nearzone


Table 1
Correction of the near zone (a0.2, b0.2)
Under- temperature
Ti-Tr| Maximum velocity
m/s| Mean velocity
m/s| Correction
factor
---|---|---|---
-3K| 0.20
0.25
0.30
0.35
0.40| 0.10
0.12
0.15
0.17
0.20| 1.00
0.80
0.70
0.60
0.50
-6K| 0.20
0.25
0.30
0.35
0.40| 0.10
0.12
0.15
0.17
0.20| 0.10
0.12
0.15
0.17
0.20
Lindab reserves the right to make changes without prior notice
2021-01-05
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