• Plenum for connecting SLM linear slot diffuser supply/exhaust unit to ductwork
• Ensures proper function of the supply air diffuser
• Access for ductwork cleaning

PRODUCT MODELS & ACCESSORIES

• Model with sound attenuation material
• Detachable airflow rate measurement and balancing module.

The plenum shall be made of galvanised steel.

The plenum shall comprise an airflow measurement and adjustment module.

The diffuser shall be detachable in order to provide access to the measurement and adjustment module in the plenum.

The plenum shall comprise sound attenuation material made of mineral wool.

The plenum reduces duct pressure and air velocity in order to supply air throughout the entire face area of the linear diffuser and improve the air distribution quality.

• Introduction
• Dimensions
• Material
• Accessories
• Function
• Installation
• Adjustment
• Servicing
• Specification
• Product Code

Introduction ▲

PLM

Plenum for SLM Linear slot diffuser

 

• Plenum for connecting SLM linear slot diffuser supply/exhaust unit to ductwork
• Ensures proper function of the supply air diffuser
• Access for ductwork cleaning

Product Models & Accessories

• Model with sound attenuation material
• Detachable airflow rate measurement and balancing module.
   

Dimensions ▲

DIMENSIONS

 

Slots	H	K	K1	ØD
1	235	130	59	160
2	275	181	110	200
3	325	232	161	200
4	325	283	212	250

 

Standard dimensions for SLM+PLL

Diffuser active length (mm)	572	872	1172	1472	1772
L (mm)	571	871	1171	1471	1771
L1 (mm)	286	436	586	368	443
Duct connections (pcs)	1	1	1	2	2

In addition to standard linear slot diffuser sizes, other sizes can be ordered.
The maximum length is 2000 mm.
Continuous plenums with modular design are also available for installation lengths greater than 2000 mm.
 

Material ▲

 

 

MATERIAL AND FINISHING

PART	MATERIAL	NOTE
Plenum box / spigot	Galvanised steel	Spigot equipped with rubber gasket
Sound attenuation material	Mineral wool	The mineral wool is fixed with nails

Accessories ▲

 

 

ACCESSORIES

ACCESSORY	CODE	DESCRIPTION
Sound attenuation material	IN	Mineral wool in the PLM plenum on 2 sides (IN=2)
Sound attenuation material	IN	Mineral wool in the PLM plenum on 5 sides (IN=5)
Airflow measurement and adjustment unit	OM	For supply installation

Function ▲

 

 

FUNCTION

The duct pressure and air velocity are reduced inside the PLL plenum box.
Air is supplied into the space through the diffuser, improving the air distribution quality.
The airflow rate can be adjusted using the optional measurement and adjustment module MSM.

Installation ▲

 

INSTALLATION

CODE DESCRIPTION
1  PLENUM
2  MEASUREMENT AND ADJUSTMENT MODULE

The PLM is installed into the suspended ceiling with M8 drop rods (not supplied in the delivery) and connected to the ductwork with a spigot equipped with an integral rubber gasket.
When equipped with a measurement and adjustment module, the recommended safety distance upstream of the device is at least 3D, in order to ensure a reliable airflow rate measurement.
The units control spindle must not be excessively bent.
 

Adjustment ▲

 

 

ADJUSTMENT

In order to enable airflow adjustment and measurement of airflow rate, it is recommended that the diffuser be connected to the plenum equipped with the MSM module.
The supply flow rate is determined by using the measurement and adjustment module MSM.

Detach the diffuser and pass the tubes and control spindle through the diffuser.
Replace the diffuser.

Measure the differential pressure using a manometer. The flow rate is calculated using the formula below.


 

where:

∆Pm is the measured pressure (Pa)
k is a factor given as a function of mounting and diameter
Qv is the airflow rate (l/s)

 

Adjust the airflow rate by rotating the control spindle until the desired setting is achieved.
Lock the damper position with a screw.
Replace the tubes and spindle into the plenum and replace the diffuser.

K-factor for installations with different safety distances (D= duct diameter)

 

	Safety distance
Sigot Diameter	> 6XD	min 3XD
160	19	22
200	49	32
250	51	51

Servicing ▲

SERVICING

Remove the measurement and adjustment module by gently pulling the shaft; (not the control spindle).
Wipe the parts with a damp cloth, instead of immersing in water.
Reassemble the measurement and adjustment module by pushing the shaft back into place until the module meets the stopper.

Specification ▲

SUGGESTED SPECIFICATIONS

• The plenum shall be made of galvanised steel.
• The plenum shall comprise an airflow measurement and adjustment module.
• The diffuser shall be detachable in order to provide access to the measurement and adjustment module in the plenum.
• The plenum shall comprise sound attenuation material made of mineral wool.
• The plenum reduces duct pressure and air velocity in order to supply air throughout the entire face area of the linear diffuser and improve the air distribution quality.
  
   

Product Code ▲

PRODUCT CODE

PLM/S-L-D-N

   S = Number of slots    1, 2, 3, 4

   L = Length
    372, +1, .., 50000

   D = Diameter of duct connection
    S=1: 160
    S=2 or S=3: 200
    S=4: 250

   N = Number of duct connections
    1, +1, .., ((L-30)/(D+30)1)

Specifics and accessories

   IN = Sound attenuation material    

    N  No attenuation material
    2  Sound attenuation material on 2 sides
    5  Sound attenuation material on 5 sides

   OM = Measurement/Adjustment module MSM
    N  No measurement and adjustment module
    Y  MSM installed in each duct connection
 

 

Code example

   PLM/1-400-160-1, IN=N, OM=N