Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants
Lawrence Webster Forrest (LWF), Fire Engineering and Fire Risk Management Consultants



Navigation

Client login
Forgotten password
Follow us on Twitter Follow us on Facebook Subscribe to our blog

Lawrence Webster Forrest
Legion House
Lower Road
Kenley
Surrey
CR8 5NH

Tel: +44 (0)20 8668 8663 Fax: +44 (0)20 8668 8583
E-mail: fire@lwf.co.uk

Facilities Management & Fire Safety - Gaseous Systems - Part 23

Posted by LWF: 31/08/2017 15:04

In this blog series on fire safety and fire protection methods for people who work in Facilities Management, we are looking at fixed fire-fighting systems and how they are used to protect a building and its occupants in case of fire. 

Although sprinkler systems are very commonly used, they are not the only fixed fire protection system in use in the UK and around the world. In Part 22, we talked about the use of gaseous systems over the years and what gases are in use following the wide-scale banning of halon in 2003.  In Part 23, we’re going to take a look at the clean gaseous agents which have been created since that time, which, unlike halon, don’t have a detrimental effect on the ozone layer.

The new agents which have been developed can be put into two categories –
halocarbons and inert gases. Halocarbon gases are similar in chemical composition to halon, however they are created to cool the flames of the fire rather than interrupting the chemical process of the fire. This means that while it is less harmful to the environment, it is not as efficient as halon 1301, leading to the need to use it in higher concentrations to match effectiveness. 

The agents used in halocarbon gases are hydrofluorocarbons, such as HFC 227ea (CF3CHFCF3, being the most commonly-used), and a fluorinated ketone FK-5-1-12 (CF3CF2C(O)CF(CF3)2, which is known commercially as Novec 1230. Other halocarbons are in use, but are very rarely seen in the UK.

Inert gas systems work entirely differently to halocarbon gas systems. The role of the inert gas is to reduce available the oxygen concentration in the affected area to a point where the fire simply cannot be sustained. 

The modern inert gas systems are safer than CO2 systems in areas where a CO2 system cannot be used due to the dangers for living beings, although they work largely on the same principle. The amount of oxygen left in the applicable area after the use of one of the newer inert gases is capable of sustaining life.

There are four main inert gas agents in use in an inert gaseous system. These are:

IG-541 (52 percent nitrogen, 40 percent argon and 8 percent CO2)
IG-55 (50 percent argon and 50 percent nitrogen)
IG-01 (100 percent argon)
IG-100 (100 percent nitrogen)

The chemical composition is one way in which the inert gases and the halocarbons differ, but there are other factors which will affect the choice of which type of system is most appropriate for a given situation or building.  

In Part 24 of this series, we will look at those influencing factors. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact Peter Gyere in the first instance on 0208 668 8663.

Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years' experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.

Leave a reply

  *

  *

 


CAPTCHA Image

[ Change the image ]


*Required

Subscribe to our fire safety blogs

Bulletins
Email Format
* indicates required

FIRE SAFETY BLOGS

  • Fire Engineering Design and Risk Assessment - Hazard Classifications - Part 13

    In LWF’s current blog series on Fire Engineering Design and Risk Assessment, written for architects and others in the house design and build industry, we have been looking at the use of sprinklers as part of a fire protection plan. In part 12, we discussed those areas of a build where sprinkler use might not be appropriate and how active or passive fire protection alternatives can be used instead. In Part 13, we’ll talk about...

    Read more...

  • Facilities Management & Fire Safety - Gaseous Systems - Part 26

    In LWF’s blog series for those who work in Facilities Management or who have a responsibility for fire safety as a part of their job, we have been looking recently at the use of gaseous systems as a method of fire protection. Gaseous systems are most commonly used in circumstances where sprinkler systems are not appropriate. In part 25 we talked about the use of fusible links which melt to actuate the release control of...

    Read more...

  • Fire Engineering Design and Risk Assessment - Sprinkler Design Codes - Part 12

    In this Fire Engineering Design and Risk Assessment blog series by LWF for Architects and others in the building design business, we have been discussing sprinklers and the design codes affecting installation and use. In Part 11, it was noted that there may be areas of a building in which sprinklers are not advisable but that in these cases, suitable alternative protection must be provided. With that in mind, most design codes lay out the...

    Read more...

  • Facilities Management & Fire Safety - Gaseous Systems - Part 25

    In LWF’s blog series on fire safety for those who work in Facilities Management or who have a responsibility for fire safety in the workplace, we have been looking recently at the use of gaseous systems as a fire protection method. In Part 24, we talked about the different types of gaseous system and how and where they can be used. In Part 25, we’ll discuss the design codes involved before moving on to look...

    Read more...

  • Facilities Management & Fire Safety - Gaseous Systems - Part 24

    In LWF’s blog series on fire safety for those who work in Facilities Management, we have been looking at the use of gaseous systems as a fixed fire protection system. In Part 23, we established that since halon was phased out in 2003, CO2 systems continued to be used and in recent years, two new categories of gaseous agents were established – halocarbons and inert gases. In Part 24, we’re going to look at the...

    Read more...

Case Studies

The Wohl Neuroscience Institute - Fire Safety, Strategy & Engineering
Key Facts: Client: King’s Clinical Neuroscience Institute Project Manager: MACE Ltd Designers: Devereux Architects/Allies and Morrison Approximate Size: 7,400m2 Description of the Project:...

Read more..

General Bulletins

Fire - The External Risk
When we consider fire safety, our focus is normally from within, what can we do to prevent the occurrence of fire and how we can limit its damage.  Whilst this is the correct stance to take, we m...

Read more..

Technical Bulletins

Evacuation Modelling - Factor in Human Behaviour
Evacuation of buildings can be analyzed in different ways. Approved Document B (ADB) which provides guidance on meeting the requirements of the England and Wales Building Regulations with regard to fi...

Read more..

Site map | Web development London