TC18HCWL – Rytons 9×6 Cowled Ventilation Set with Hit & Miss Ventilator

General Details

TC18HCWL – Rytons 9×6 Cowled Ventilation Set with Hit & Miss Ventilator

  • Telescopic cavity liner set with external cowl for background room ventilation.
  • Allows the introduction of fresh outside air into the room to disperse moisture, odours and other airborne pollutants.
  • External cowl protects against excessive weather conditions and alleviates air blasts through the cavity.
  • Telescopic cavity liner contains a system of internal baffles to reduce light and draughts.
  • Internal hit & miss grille manually adjusted with a sliding action allowing ventilation to be controlled as required.
  • Cowl, air brick and hit & miss grille U.V. stabilised to slow down the effects of sunlight.
  • External water baffles prevent transfer of water across the cavity.
  • Position at high level (typically 1.7m above floor level) for all dwelling types and storey heights.

Equivalent Area:

  • 18,000mm² (180cm²) per set (tested to BS EN 13141-1:2004 and independently verified by the BRE).


  • Cowl: 255mm L x 154mm H x 74mm D.
  • AirLiner sleeve: 220mm W x 140mm H, extends from 250mm to 404mm L (including air brick) (see image gallery).
  • Hit & Miss grille: 271mm L x 171mm H.


  • Terracotta: TC18HTCWL.
  • Buff/Sand: TC18HBCWL.
  • White: TC18HWCWL.
  • White hit & miss grille.


  • Cowl and hit & miss grille: U.V. stabilised high impact polystyrene.
  • Multifix Air Brick: U.V. stabilised polypropylene.
  • AirLiner sleeve: Polypropylene.
  • AirLiner sleeve contains recycled plastic.


  • No special fixing required. Build in the cavity liner with fitted air brick as work proceeds. Extend the telescopic sleeve as necessary. Fasten the cowl to the brickwork. Fasten the hit & miss ventilator internally.
  • To comply with Building Regulations Part F the ventilator should be sited not less than 1.7m above floor level.

Handling Information:

  • Box quantity: 1 set.
  • Box size: 27cm W x 28cm H x 18cm D.
  • Box weight: 0.95kg.

Reference Material:

  • Equivalent area tested to BS EN 13141-1:2004 and independently verified by the BRE.
  • Also refer to: The Building Regulations 2000, Approved Document F,
  • The Building (Scotland) Regulations, Mandatory Standard 3.14,
  • The Building Regulations (Northern Ireland) 2000, Technical Booklet K,
  • British Standard BS 5250.

NBS Plus Specification: