Greenwood | Low Energy Bathroom Fan, Heat Recovery System, Whole House Ventilation

HD Vent

HD Vent is a shutter style slotvent offering high equivalent area performances from two models and is available in a range of colours. Front operation only.
Features & Benefits
Models & Control Options
Download Documents
Features and Benefits


The HD Vent is a shutter style Slotvent, designed to provide background ventilation in line with current Building Regulation performance as set out in ADF 2010.  Available in a range of colours, two sizes provide up to 6800mm² equivalent area airflow performance.


Key Stats;

  • Two models available in four configurations for window profile and over-frame installation applications


  • For window profiles; 2 models offering 3200 and 6400mm² Equivalent Area (England & Wales)


  • For overframe; 2 models offering 3400 and 6800mm² Equivalent Area (England & Wales)


  • 4000 and 8000mm² Free Area (Scotland)


  • Designed to deflect air upwards when open to eliminate issues with draughts when the Slotvent is installed


  • High performing external louvered grille which offer excellent weather protection is provided as external component


  • Recessed flyscreens provided for over-frame installations


  • Front operation


  • Available in white, brown and brilliant white - RAL colours available on request


  • Fully accredited and tested
    The HD Vent has been independently tested at a third party accredited test house to all of the current British Standards.  Please see performance tab for full air permeability, Watertightness, noise and equivalent area performance information. 

Models & Control Options

Physical Specification
Product code  4000HDF  8000HDF  4000HDFF 8000HDFF 

HD Internal &

HEG Grille 

HD Internal &

HEG Grille

HD Internal &

AEF Flyscreen 

 HD Internal &

AEF Flyscreen 



 3200 6400  3400  6800 


(mm) l x h x d

 278 x 28.5 x 13 560 x 28.5 x 13  278 x 28.5 x 13  560 x 28.5 x 13 

 Slot height


18  18  18  18 

 Slot size (mm)

Length - Central gap - Length

235   235 - 20 - 235 235   235 - 20 - 235 
 Control  F F F
 Colour  W, B, BW   W, B, BW  W, B, BW   W, B, BW 

Scottish Building Regulations: Free Area Performance (see page 9 for full details). 4000HDF/HDFF = 4000mm², 8000HDF/HDFF = 8000mm². Control: Front (F). Colour: White (W), Brilliant White (BW), Brown (B).

Quick Quote

Take a few moments to try out our quote form

Copy Specs

Click here to copy this product's specification


Click here to register for our latest promotions


Facebook Twitter Pinterest Google Plus Linked In

Zehnder Group