Ventilation Louvres:
1UL Universal Louvre Vent System

1UL ventilation louvres are a roll-formed Single Bank Louvre System designed for screening or cladding and ventilation applications when rain defence is not a priority.

The 1UL is available either in deep or shallow section, as a horizontal or vertical louvre, with a wide variety of effects such as perforated or stucco embossed. It may be combined with other Colt products such as rooflights and glazed facades.

For rain defence applications, see 3UL, ERD or 2UL (for plant room ventilation).


There are two front louvre vent profiles:

  • Shallow (50mm pitch)
  • Deep (100mm pitch)

There are two arrangements:

  • Horizontal
  • Vertical

Both arrangements can also be inverted. Both arrangements can be inverted for roof screens, which is important when wishing to hide items which are high up, such as plant rooms.

There are three options for the principal components:

  • Aluminium
  • Galvanised Mild Steel
  • Stainless Steel

Perforated, stucco and pre-coated materials are also available and can be used to singular effect (subject to material specification and quantity).

There are many decorative finish options, including:

  • Mill Finish (aluminium)
  • Stoved Polyester Powder Paint
  • Anodised (aluminium)

Perforated, Stucco and Pre-Coated Ventilation Louvres are also available on request for larger applications.

The applied finishes can be supplied in two coverage levels:

  • Total (all principal components)
  • Partial (front louvres and frames only).

There are a large selection of optional accessories such as:

  • Mitred Corners
  • Blanking Panels
  • Special Shapes
  • Acoustic Modules
  • Guards (bird/ insect/ security)*
  • Doors
  • Turrets

* With all guards, particularly insect mesh, the design should allow for additional resistance to airflow and reduced flow rate performance.

Performance specification

The 1UL louvre vent system achieves minimum performance coefficients (Cv) of 0.43 (inlet) and 0.38 (extract). These have been established as the result of full-scale wind tunnel tests.

Single bank louvres are ideally applied in sheltered locations or where rain penetration may be acceptable. The louvre vent system will achieve Class D1 when tested at all velocities to EN 13030:2001.

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