Consider the ancillaries when specifying weather louvres

Posted by Paul Compton on 03/05/16 12:00

Royal_Mail_2UL.jpgWhen specifying weather louvres, it is important to consider an often neglected part of the louvre specification: the ancillaries. I have previously written about the key considerations when specifying louvres, which guides you through some important areas when specifying louvre. However, once these requirements have been met, you must also consider the following:

Blanking Panel

Used to cover areas of louvre where ventilation is not required, it is often written into the specification, but the description is usually vague.

It is important to be specific about your U-Value requirements: stating insulated blanking panel will not guarantee that you get the U-Value that you want.

Insulated blanking panel can be made to any thickness, from many different materials, and the U-Values vary considerably. If the required U-Value is unknown, a safe option is to state 0.3W/m2K, as this prevents suppliers from providing an insulated panel with a poor U-Value.

Bird or Insect Guard?

It may seem like a good idea to have both, however they restrict air flow and raise the pressure drop through the louvre. This means that the louvres may need to increase to accommodate these options.

Insect guard is a finer mesh than bird guard and will create a greater restriction. When specifying, it is worthwhile considering a compromise and asking yourself whether insect mesh is important or birdguard will suffice.


Attenuators will provide varying degrees of sound reduction: to enable a proper calculation, your specification should provide the sound spectrum of the noise source and the acceptable noise level at the distance from the louvre.

Fire Resistance

Providing fire resistance can be difficult because louvres are designed to provide ventilation, not restrict it. Fortunately it is not a common requirement and it can be achieved by providing a fire damper or an insulated fire resistant panel behind the louvre. 

The fire resistance requirements should be stated clearly, for example in terms of time against integrity, insulation or radiation.

Some resources to aid you when specifying weather louvres:

Webinar - Key considerations when specifying weather louvres - 13th May 2016

Join Conor Logan, Technical Manager at Colt UK, from 12.30-13.30 GMT on Friday 13th May 2016, as he presents a free CPD webinar on the design considerations when specifying weather louvres.

This webinar has been developed to help Architects and Service Engineers ensure that specifications adequately reflect design requirements and performance expectations.

Watch the webinar

Louvre selection tool

Over the years we have helped many customers with their selection of the correct louvre system. We’ve created a tool to assist with this, based on what level of weather protection and aerodynamic performance is really needed.  

Download UL Selection tool

Paul Compton Paul Compton is Technical Director for Colt, experienced in smoke control, HVAC, solar shading and louvre systems.

Contact me now  New Call-to-action Connect on LinkedIn

Topics: Natural ventilation, Louvre