Skip to main content

Internal Metal Grilles

Internal metal ventilation grilles are a range of metal louvre grilles, hit and miss vents and return air grilles manufactured in high quality pressed aluminium. (Please note that hit & miss grilles must not be used for ventilation in connection with gas appliances).

Available in three types of finish: plain aluminium (A), brass anodised (BA) and polished brass (PB).

Louvre grilles are a permanently open vent with no flyscreen or closing method but with visible airflow marking to comply with the requirements of BS5440 Part 2 2000 and BS EN 13141-1 2004 (suitable for gas appliance ventilation).

Adjustable (hit & miss) grilles can be open or closed with an integral flyscreen (not suitable for gas appliance ventilation).

Attractive products for sustaining airflow and reducing draughts.

For more information call 01405 765567 Free next day delivery *

View product range & add to quote

Features & Benefits

  • Aesthetically pleasing
  • Simple screw fixing
  • Excellent airflow properties


  • Backgroung ventilation
  • Heat producting appliance ventilation (open louvre grilles only)

Technical Information

Please see the Product Detail range table for ‘equivalent area’ data.

Installation Advice

Through the wall ventilators provide passive ventilation through external walls into habitable rooms. It is important to differentiate between a ventilator which is required to provide general background ventilation and one which provides air into a room which contains a heat producing appliance, such as a central heating boiler or gas fire.

If only general background ventilation is required, then product selection is less critical.

A habitable room requires a free airflow of 8000mm² in order to comply with Building Regulations. This can be provided by using two Timloc airbricks complete with cavity sleeves and internal louvre or hit and miss grilles. Alternatively, any one of the anti-draught ventilator products can be used.

If the room contains a heat producing appliance, the provision of constant and reliable ventilation is vitally important. The anti-draught ventilator products are strongly recommended for this application, as they fully comply with legislation governing gas and heating appliances.

The size and number of anti-draught ventilator products required, will be dictated by the requirements of the particular heating appliance, it is strongly recommended that advice is sought from the manufacturer.

General recommendations for the specification and use of through the wall ventilation are detailed below:

  • always check that the appropriate size and number of through the wall ventilators are used to suit the application
  • never just fit an airbrick - a cavity sleeve must always be fitted to the back of the airbrick to ensure that the air is transmitted effectively through the wall and into the room
  • hit and miss grilles may only be used for general background ventilation, they must never be used to ventilate any kind of gas or heating appliance
  • internal grilles should be positioned over the internal opening of the cavity sleeve and fixed to the wall using screws and wall plugs
  • ventilators used to provide air for gas or heating appliances must be permanently open, there must be no facility to block or close the ventilator ( they also must not contain any kind of fine mesh or insect screen)
  • through the wall ventilators should always be fitted well above the external ground level, so as to ensure that rain and snow water cannot enter the ventilator
  • it is recommended that a section of horizontal cavity tray is installed directly above the through the wall ventilator, to prevent water from tracking across the cavity sleeve from the outer leaf to the inside of the building
  • in order to help reduce the effect of draughts, it is worth considering positioning the through the wall ventilator close to any heating appliance, rather than at the opposite side of the room,
  • positioning the ventilator at a higher level, rather than close to the floor will also be of assistance.

Material and Colour Choices

  • Manufactured in high quality pressed aluminium
  • Available in 3 types of finish – plain aluminium, brass anodised and polished brass
  • nbs plus
  • riba

Web Design by Bluestorm