Skip to main content
Facilitate Magazine: Informing Workplace and Facilities Management Professionals - return to the homepage Facilitate magazine logo
  • Search
  • Visit Facilitate Magazine on Facebook
  • Visit Facilitate Magazine on LinkedIn
  • Visit @Facilitate_Mag on Twitter
Visit the website of the Institute of Workplace and Facilities Management Logo of the Institute of Workplace and Facilities Management

Main navigation

  • Home
  • News
    • Comment
    • People
    • Reports
    • Research
  • Features
    • Analysis
    • Features
    • Round Tables
    • Webinars
  • Outsourcing
    • Contract Finder
    • Contracts
    • FM Business Models
    • Interviews
    • Mergers & Acquisitions
    • Opinion
    • Procurement
    • Trends
  • Know-How
    • Explainers
    • Legal Updates
    • White Papers
  • Jobs
  • Topics
    • Workplace Services
      • Hospitality
      • Catering
      • Cleaning
      • Front of House
      • Grounds Maintenance
      • Helpdesk
      • Mailroom
      • Manned Guarding / Security
      • Pest Control
      • Washroom Services
      • Disaster Recovery
      • Specialist Services
    • Professional Performance
      • Behavioural Change
      • Continual Professional Development
      • Education
      • Management
      • Recruitment
      • Training
    • Workplace Performance
      • Benchmarking
      • Health & Wellbeing
      • Operational Readiness
      • Procurement
      • Security
      • Workplace User Experience
      • Workplace Culture
    • Compliance
      • Health & Safety
      • Risk & Business Continuity
      • Standards
      • Statutory Compliance
    • Building Services
      • Architecture & Construction
      • Asset Management
      • Building Controls
      • Building Fabric
      • Drinking Water
      • Fire Protection
      • HVAC
      • Landscaping
      • Mechanical & Electrical
      • Building Security
      • Water, Drainage & Plumbing
    • Technology
      • Building Information Modelling
      • CAFM
      • Data & Networks
      • Document Management
      • Information Management
      • Internet of Things (IoT)
      • Software & Systems
    • Energy management
      • Energy Management Systems
      • Electricity
      • Gas
      • Solar
      • Wind
    • Sustainability
      • Environmental Quality
      • Social Value
      • Waste Management
      • Recycling
    • Workspace Design
      • Agile Working
      • Fit-Out & Refurbishment
      • Inclusive Access
      • Lighting
      • Office Interiors
      • Signage
      • Space Planning
      • Storage
      • Vehicle Management / Parking
      • Washroom
    • Sectors
      • Corporate Office
      • Education
      • Healthcare
      • Manufacturing
      • International
      • Retail
      • Sports & Leisure
      • Regions
  • Buyers' Guide
Quick links:
  • Home
  • Topics
Know How
Compliance
Health & Safety

Louvre window systems

Open-access content Wednesday 4th September 2013 — updated 1.53pm, Tuesday 5th May 2020
At a time where demand for environmental efficiency is ever-increasing, Simon Hunter outlines how important louvres can be in meeting environmental legislation requirements.


6 September 2013

It is estimated that 45 per cent of the UK's carbon dioxide emissions come from buildings, principally from space heating and cooling, water heating and lighting.


In an effort to demonstrate corporate social responsibility towards the environment, building owners are increasingly seeking to improve the environmental credentials
of both new and existing building stock.

A good way of improving energy performance is to ensure that a building's louvre system is as efficient as possible.

Louvres are window shutters with horizontal slats, which are angled to admit light and air, but to keep out rain, direct sunshine and noise.

Improving its efficiency means specifying the most appropriate louvres for a new building or replacing ageing louvres with new, high performing systems.

This is because, as well as allowing natural ventilation to a building, an efficient louvre system can improve air flow while protecting these openings against rain ingress. As a result, less power is needed to move the volumes of air required and, in the case of HVAC systems, improved energy efficiency can sometimes mean a smaller and less powerful system is required for space heating and cooling.

Louvre design is continually developing in response to demand for better water protection and, as a result, the latest systems are a long way from the simple screening louvres of the past.


Multi-use

Screening louvres are still suitable for locations where water penetration will not cause significant problems (such as screening of rooftop plant or in a multi-storey car park). They typically have simple blade shapes, which allow good air flow, but give limited defence against rain. Standard drainable blades, on the other hand, give good air flow and some rain defence, but do not perform as well with wind-driven rain. They are used when occasional ingress is not a major concern and where some drainage of cascading water is required.

Storm-resistant or performance louvres typically provide moderate -to-good air flow with excellent defence against wind-driven rain. They are used when high levels of ventilation and maximum protection from the rain is needed, for instance when sensitive equipment such as HVAC plant is behind the louvre.

The type of louvre system chosen will depend on the balance being struck between air flow and water ingress. All louvres restrict the passage of air. This resistance is called a 'pressure drop'. Too high a pressure drop and not enough air will be allowed through, which can cause a rapid temperature rise inside a building, in turn causing problems with generators and HVAC equipment.


Specification

Louvre specification needs to consider a number of factors, including site location, prevailing weather conditions (in particular wind direction) and the location and exposure of the louvres (which will dictate air flow rate and the amount of potential wind-driven rain).

These factors should then be balanced with the required air flow, the maximum acceptable pressure drop, the degree and depth of acceptable water penetration and finally, the building's exterior design.

As louvres are an integral part of the building envelope, aesthetics are important, but it is essential performance is not compromised. Louvres come in a wide range of designs, colours and finishes to suit most buildings. They can be hidden behind features or perforated panels (which can also act as bird and insect screens), but this can obviously increase resistance to air flow. Additionally, most performance louvres can be shaped (for example to create curves) but this can impact on drainage capabilities.

A well-designed louvre will reduce the pressure drop, allowing a larger volume of air through and thus cutting the amount of fan power needed to deliver the required air flow. Conversely, poor specification can lead to rainwater ingress, not enough ventilation, wasted energy and poor performance, not only of the equipment being ventilated, but of the entire building.

Louvres are an excellent way of helping facilities managers meet ever-more demanding environmental legislation and client requirements for sustainable buildings, playing an important role in improving energy efficiency, lowering power consumption and reducing carbon emissions. However, to help improve a building's energy performance and get the best possible results from a louvre system, it is crucial that it is correctly specified.


Louvre specification
Traditionally, louvres are specified based on free area (typically 50%), calculated by measuring the clear distance between the blades and multiplying it by the width of the louvre panel (or height, if the blades are arranged vertically).

Free area is dictated by the size of the louvre, with industry commonly using a 1m by 1m louvre when quoting free area. However louvres are never precisely this size. Free area is also affected by other factors, such as additional structural support, or if bird screens or insect
meshes are fitted.

There is a need to move away from specifying louvres purely on free area. A number of factors need to be considered, including site location, prevailing weather conditions (in particular wind direction) and the location and exposure of the louvres (which will dictate airflow rate and the amount of potential wind-driven rain).


Simon Hunter, product manager of louvres at Construction Specialties
Also filed in:
Topics
Know How
Content
Compliance
Health & Safety

You might also like...

Share
  • Twitter
  • Facebook
  • Linked in
  • Mail
  • Print

Today's top reads

 

Latest Jobs

Project Leader (Maternity Cover One Year Contract)

Cambridge
Circa £50,000 Pro Rata + Benefits & Opportunities
Reference
56378

Maintenance Supervisor

Surrey
Up to £43,000 + Excellent Package & Opportunities
Reference
56376

Regional Facilities Manager

South West England
Circa £40,000 + Benefits & Opportunities
Reference
56375
See all jobs »

 

 

Sign up to our newsletter

News, jobs and updates

Sign up

Subscribe to print

Sign up to receive our bi-monthly magazine

Subscribe
Facilitate magazine cover, June 2020
​
FOLLOW US
@Facilitate_Mag
Facilitate Magazine
Facilitate Magazine
CONTACT US
Contact us
Tel: 020 7880 6200
​

IWFM

About IWFM
Become a member
Qualifications
Events

Information

Privacy Policy
Terms & Conditions
Cookie Policy
Think Green

Get in touch

Contact us
Advertise with us
Subscribe to Facilitate Magazine
Write for Facilitate Magazine

General

IWFM Jobs
Help

© 2022 • www.facilitatemagazine.com and Facilitate Magazine are published by Redactive Media Group. All rights reserved. Reproduction of any part is not allowed without written permission.

Redactive Media Group Ltd, 71-75 Shelton Street, London WC2H 9JQ