Colt 3UL Universal Louver fixed metal weather louvre system

Colt 3UL Universal Louver is a roll-formed triple bank louver system designed for applications requiring ventilation with the maximum degree of rain defence.

Product information

Generic types

Colt 3UL Universal louver is a roll-formed or extruded double bank system, used for screening and/or ventilation. It is designed for use where rain defence is of the utmost importance.

3UL is a triple bank louver system When rain defence is needed, we recommend the use of either 2UL or 3UL. When rain defence is not of primary importance, we recommend the use of 1UL.

Colt Universal louver can be uniquely configured to provide the solution to your needs.

Features and benefits of Colt Universal louver

Highly aerodynamically efficient – this reduces air resistance, allowing the plant and the aperture to be minimised thereby saving running costs.

Enhanced rain defence performance - 2UL and 3UL versions have high resistance to rain ingress. Unlike other louver types, Colt 2UL and 3UL panels have efficient drainage paths into their hollow section mullions, which in practice further increases their rain defence effectiveness.

Durable and maintenance free – UL is completely made from corrosion resistant materials.

Thermal expansion of the louvers enabled – the louvers are clipped (and not riveted or screwed) to structural supporting mullions.

Proven performance - UL has been tested to EN 13030:2001.

Easy to install – UL can either be delivered to site pre-assembled or as a kit of parts.

A wide range of options - it is available in various shapes, configurations, materials, finishes and coatings to meet the requirements of almost any project. See the options tab.

louvers can be extruded or roll-formed; either mill finish, polyester powder painted or anodised; plain, perforated or stucco embossed.

louver panels can incorporate mitred corners, special shapes and louver doors. Colt also has a range of turret units.

If noise reduction is required, acoustic louver panels may be used.


Universal louver has been tested to EN 13030:2001. See the performance tab for the test results.

We are at your service

We provide a pre-order design service. We also offer complete project management, installation, wiring and commissioning, which means that we take complete responsibility to ensure that the product is in full working order within one package of works.

Please contact us for more information relating to the application, specification, installation or servicing of this product.



Colt Universal louver is a versatile louver system providing either screening and/or rain defence in a wide variety of product options, materials and finishes.

louver blades form an aerodynamically efficient profile to achieve a high degree of rain defence. Allowance is made for thermal expansion without distortion along the length of each louver blade. Water drains efficiently onto the cill through the mullions.

Mullions are concealed at maximum 49.21" / 1250mm centres and the points of support along their length are set in accordance with prevailing site wind pressures (as calculated and specified by a structural engineer).

System Types

  • Universal louver 3UL/SH - Triple bank shallow section, front louvers at 1.96" / 50mm pitch
  • Universal louver 3UL/DH - Triple bank deep section, front louvers at 3.93" / 100mm pitch


  • Horizontal
  • Horizontal inverted
  • Vertical


  • Aluminium
  • Mild steel
  • Stainless steel


  • Plain
  • Perforated
  • Stucco embossed

Colours/ finishes options

  • Mill aluminium
  • Anodised aluminium
  • Polyester powder coated to a RAL colour, list of colours upon request
  • PVF2

Paint coverage

  • Not relevant
  • Total
  • Partial


  • None
  • Aluminium bird guard
  • Galvanised steel bird guard
  • Stainless steel bird guard
  • Aluminium fly guard
  • Stainless steel insect mesh

Blanking panels

  • None
  • Single skin aluminium panel, mill finish
  • Single skin aluminium panel with external decorative polyester powder paint finish to match louvers
  • Insulated panel

Noise control

  • None
  • Type R acoustic louver panels - Optimum acoustic performance with normal pressure drop
  • Type LP acoustic louver panels - Normal acoustic performance with minimum pressure drop


  • None
  • Visible frame double door
  • Visible frame single door
  • Concealed frame double door
  • Concealed frame single door
  • Turret unit(s)
  • Circular panel(s)
  • Triangular panel(s)


Aerodynamic performance

  • Universal louver 3UL/SH - minimum performance coefficient (Cv) of 0.277 (inlet) and 0.22 (extract). This is equivalent to Class 3 to EN 13030.
  • For data on DH (deep) versions, please contact Colt.

Rain defence performance (to EN 13030)

Class A - up to 3.5m/s suction velocity. Triple bank louvers offer maximum rain defence.

For data on DH (deep) versions, please contact Colt.


  • Tested to EN 13030:2001
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