Introduction
The proprietary plenum boxes for our Fan Coil Diffusers are designed to guarantee a good distribution of the air prior to diffusion through the terminals. Available with Side or Top Entry connections to customer-specific diameter/shape, these can be fitted with Spigot flap dampers FD, cord- or quadrant-operated, as well as 6mm acoustic lining (optional) reaction to fire class
C-s3-d0 to EN 13501-1: 2007 to avoid noise generation.
Also available with rivet fix (hem fix as standard).
Product Description
- PBHLHHigh-line Plenum box to suit FCD Fan Coil Diffusers
- PBLLHLow-line Plenum box to suit FCD Fan Coil Diffusers
- SESide Entry spigot
- TETop Entry spigot
- CCCircular connection
- RCRectangular connection
- FOFlat Oval connection
- FDCCord-operated Flap damper (optional)
- FDQQuadrant-operated Flap damper (optional)
- LINED6mm acoustic lining (optional) reaction to fire class C-s3-d0 to EN 13501-1: 2007
- BLACKPlenum painted black to prevent through vision (optional)
Features
- Galavnised steel, stitch fixed
- Available in High-Line or Low-Line to accommodate larger spigot sizes
- 1 to 4 connections – Circular, Rectangular or Flat Oval (reduced plenum height)
- Side or Top entry spigots with optional airflow control damper
- Oblong holes on top plate for easy drop rod installation
Finish
- PBHLHGalvanised sheet steel
Dimensions
- LengthFan Coil Diffuser length
- WidthFan Coil Diffuser width
- HeightSE – Spigot diameter or height + 100mm as standard
TE – as specified by customer (200mm minimum recommended)
Order
When ordering plenum chambers please specify length width & height, spigot size and position (top or side entry) and control options. Please note that the plenum height should in general be 100mm greater that the spigot diameter (side entry applications).

Product Specification
Related links
Plenum boxes installation and maintenance
FCD Fan Coil Diffusers
Plenum Insulation Thermal & Acoustic specification
Plenum lining foam Polyester