Halton PLL – Plenum for linear slot diffuser

Overview

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

Product models and accessories

• Model with sound attenuation, mineral wool or polyester fibre
• Detachable airflow rate measurement and balancing module available.

Dimensions

^*) When reduced plenum height option (PH=R) is selected, H=D+65 mm

Standard dimensions for linear slot diffusers

In addition to standard linear slot diffuser sizes, other sizes can be ordered.
The maximum active length of one piece is 2000 mm. The minimun is 372 mm.

Continuous plenums with modular design are also available for installation lengths greater than 2000 mm.

Material

Accessories

Function

The duct pressure and air velocity are reduced inside the Halton 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

Key:
1.  Plenum
2.  Measurement and adjustment module

The Halton PLL 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 unit s control spindle must not be excessively bent.

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:

∆p_m      Measured pressure [Pa]
k           The k factor given as a function of mounting and diameter
q_v         Airflow rate [l/s]

The k-factor for installations with different safety distances
(D= duct diameter):

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.

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

The plenum is made of galvanised steel.

The plenum comprises an airflow measurement and adjustment module.

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

The plenum comprises sound attenuation material made of mineral wool or polyester fibre.

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.

Order code

PLL/S-L-D-N, IN-ST-OM-ID-ZT

S = Number of slots
1, 2, 3, 4, 5, 6

L = Active length (mm)
372, +1, .., 49972

D = Duct connection size (mm)
125, 160, 200, 250

N = Number of duct connections
1, +1, …, 322

Other options and accessories

PH  = Plenum height
S        Standard
R        Reduced (D+65 mm)

IN = Sound attenuation
N         No
2W     2 sides, mineral wool
5W     5 sides, mineral wool
2P       2 sides, polyester fibre
5P       5 sides, polyester fibre

ST  = Spigot type
G        With gasket (standard)
W       Without gasket

OM = Measurement/adjustment module (MSM)
N        No
Y        Yes (in each connection)

ID  = Diffuser assembled with plenum
N          No
Y          Yes

ZT = Tailored product
N       No
Y       Yes (ETO)

Code example

PLL/1-400-125-1, PH=S, IN=2W, ST=G, OM=Y, ID=N, ZT=N