Halton PDF – Plenum

Overview

• Plenum for connecting Halton DFB 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 material
• Detachable airflow rate measurement and balancing module available.

Dimensions

Halton PDF/H

Plenum sizes for Halton DFB diffusers are shown in grey rows in table above.

Halton PDF/V

Material

Accessories

Function

The duct pressure and air velocity are reduced inside the Halton PDA plenum.
Air is supplied into the space through the diffuser, improving the air distribution quality and the noise level.

The airflow rate can be adjusted using the optional measurement and adjustment module MSM.

Installation

Key:
1.   Plenum
2.   Spigot
3.   Clips
4.   Halton DFB diffuser

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

Diffuser installation
The diffuser is attached to the plenum via clips.

Adjustment

To aid in adjusting and measuring the airflow rate, it is recommended that the diffuser is connected to a plenum equipped with a MSM.
The supply airflow is determined by measuring the pressure difference with a measurement module.

Measure the differential pressure with a manometer. The airflow rate is calculated according to the following formula:

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

The k factor for installations with different safety distances
(distance of other items from the MSM):

Adjust the airflow rate by rotating the control spindle until the desired setting is achieved.
Lock the damper in position with a screw.

Replace the tubes and spindle in the plenum, and return the diffuser to its position.

Servicing

Supply and exhaust

Detach the diffuser, clean the parts by wiping with a damp cloth.
Push the diffuser back into place by clipping the plenum.

Option: MSM

Remove the measurement and adjustment module by gently pulling the shaft; (not the control spindle or measurement tubes!).
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.
Push the diffuser back into place.

Specification

The plenum is made of galvanised steel.

The plenum comprises an airflow measurement and adjustment module.

The plenum comprises 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 Halton DFB or DFC diffuser and improve the air distribution quality and the noise level.

Order Code

PDF/S-L-H-D, IN-OM-ZT

S = Model
V     Vertical
H     Horizontal

L = Length
6, 9, 12, 15, 18, 21 or 24

H = Height 
6,  9, 12, 15, 18, 21 or 24

D = Duct connection (mm)
125, 160, 200, 250, 315, 355, 400, 450, 500

Other options and accessories

IN  =  Insulation
Y      Yes
N      No

AD = Adjustment device
NA     Not assigned

ZT = Tailored product
N        No
Y        Yes (ETO)

Code example

PDF/V-6-6-125, IN=Y, OM=Y, ZT=N