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Oxygen Reduction Fire Prevention

Oxygen-reduction fire prevention is a revolution in fire safety, and the world’s latest technological innovation in fire prevention. It has the unique ability to create an environment of breathable, controlled oxygen-reduced air that prevents fire ignition. Oxygen-reduction systems prevent fire proactively instead of suppressing a fire after it has started and damage and business interruption has occurred.

Oxygen-reduction fire prevention uses a technology that produces oxygen-reduced (hypoxic) air by partly filtering out oxygen from ambient atmospheric air. Normal atmosphere contains 21 percent oxygen. The hypoxic air injected into a protected space is 15 percent oxygen and 84 percent nitrogen (1 percent is made up of argon, carbon dioxide and other gases). A fire cannot start in this environment. Common flammable solid materials and liquids cannot be ignited with an oxygen level below 16 percent.

Safe for People and Safe for the Environment
Oxygen-reduction fire prevention uses ambient air to produce breathable air for fire prevention. It is safe for people and safe for the environment – no chemicals or gases are involved. The oxygen-reduction fire prevention agent is simply oxygen-reduced (hypoxic) air.

Hypoxic environments created for the purpose of fire prevention are precisely controlled and monitored reduced-oxygen environments. They should not be confused with other environments where hypoxic conditions can occur in an uncontrolled, unwanted or unexpected way. Oxygen-reduction fire prevention systems are clean-air systems. There has been extensive medical research in the UK, Europe and Australia to support the safety of working in a hypoxic environment of oxygen at 16 percent and below.

At sea level, 15 percent oxygen content is equivalent, in terms of human physiology, to normal atmospheric air at an elevation of around 2,700 metres above sea level or being on a commercial flight. Millions of people around the world live at altitudes equivalent to exposure at or below 15 percent oxygen concentration at sea level. Hypoxic air environments are currently used for physical training and rehabilitation of athletes, as well as in medical research.

What are the Suitable Environments?
Oxygen-reduction fire prevention is best suited to any situation that requires the highest levels of fire prevention, and where uninterrupted operation is essential including high-value technical installations such as data centres, server rooms, and electrical switch rooms.

Hypoxic air has no detrimental effect on equipment. The oxygen-reduced environment slows oxidation and is perfect for preservation of irreplaceable items such as archived documents, museum exhibits, artworks and rare artefacts.

Typically, applications include: data centres; server rooms; electrical switch rooms; power correction rooms; control rooms in power plants; telecommunication rooms; laboratories; libraries; museums; archive rooms; warehouses; hazardous materials storage; food storage areas; deep freeze environments; and cold storage rooms.

How does the System Control Oxygen Monitoring?
The system is designed to enable the oxygen concentration levels to be monitored on a continual basis by a minimum of two independent oxygen sensors, in different locations, in each protected space. The monitoring units are typically placed at eye level, at an appropriate distance from the door of the room. This is to provide for monitoring of oxygen conditions and alert if doors are wedged open or not closed properly, while minimising the amount of false, high oxygen alarms. The oxygen sensors transmit to monitoring and control points (for example, the fire alarm panel and the building management system), as required.

Performance indicators show, as a minimum, for each protected space:

  • Oxygen concentration level as indicated by every oxygen sensor.
  • High and low oxygen alarm conditions.
  • An output indicating the operation of any other system alarms.
Ambient air environment compared to oxygen-reduced environment

Ambient air environment compared to oxygen-reduced environment

Health & Safety
The design aim of any oxygen-reduction fire prevention system is to create and maintain an atmosphere in an enclosure that is capable of preventing ignition of combustibles found within the protected area while simultaneously remaining safe for the occupants.

A risk assessment, in accordance with AS/NZS ISO 31000-2009, Risk management – Principles and guidelines, should be carried out prior to any installation of an oxygen-reduction fire prevention system to ensure safety of both people within the protected area and those outside the protected area that may be exposed to output air from the oxygen-reduction fire prevention system.

Such an assessment shall detail:

1The safeguards employed for people having access to the protected space and oxygen-reduction fire prevention system equipment.

2Limitations to the number of people allowed in the protected enclosure and the level and duration of physical activity permitted to be undertaken.

Oslo Museum of Cultural History, University of Oslo, Norway
The Museum of Cultural History is one of Norway’s largest cultural history museums. It holds the country’s largest prehistoric and medieval archaeological collections, including the Viking ships at Bygdøy, Norway. The museum also has a comprehensive ethnographic (study of people and their cultures) collection that includes objects from every continent, as well as Norway’s largest collection of historical coins. An oxygen-reduction fire prevention system is protecting six areas of approximately, 14,000 cubic metres.

Ministry of Defence Pension Fund, Muscat, Oman
Muscat is the capital of Oman. The city lies on the Arabian Sea, along the Gulf of Oman. It is one of the Middle East’s oldest cities. An oxygen- reduction fire prevention system is protecting nine areas in the Muscat Data Centre.

Sydney Adventist Hospital, Sydney, Australia
Sydney Adventist Hospital (SAH) is NSW’s largest single campus private hospital, a multi-award winning facility offering access to world-class doctors, nurses and other health professionals. With approximately 2,300 staff, 500 volunteers and 750 accredited medical practitioners, SAH offers comprehensive surgical, medical, and emergency services to more than 53,000 inpatients and 180,000 outpatients each year.

An oxygen-reduction fire prevention system is protecting several rooms at the SAH, including the power factor correction room and the hospital’s main switch room that feeds the operating theatres; a volume of approximately 500 cubic metres.

Installation
Oxygen-reduction fire prevention systems come readily mounted and tested. Once on site, the system is connected to the room sensors and to the power supply. The system is then connected to the rooms via the installed tubing. The by-product oxygen-enriched air is vented outside.

Oxygen-reduction fire prevention systems have a smaller footprint compared with conventional gaseous suppression systems and do not require rigid piping within the protected spaces. The only requirement is simple; minimal pressure piping to each protected area and to the ambient air, along with wiring of the oxygen monitoring units in the protected areas.

It is recommended that protected areas be equipped with highly sensitive smoke detectors such as very early smoke detection apparatus (VESDA) or equivalent. This is to ensure that any smouldering combustion from cable faults, for example, is reported in its incipient stages.

A comfortable, breathable atmosphere is created inside the protected space by the ongoing ventilation with fresh, hypoxic air. The highly reliable hypoxic air generators require very little maintenance – a maintenance cycle of six months is typical. Regular monthly inspections are recommended to ensure a fire preventative atmosphere is maintained.

Oxygen-reduction fire prevention systems can be implemented as an alternative, but also as a complementary or supplementary option that enhances the conventional fire-safety means without interfering with their performance.

System Configuration

System Configuration

Sealing the Rooms
It is essential the protected area is well sealed in order to minimise the permanent leakage of air in and out of the room. The key factor relating to running costs (energy consumption and maintenance) of an oxygen-reduction fire prevention installation is the leakage. This is the sum of permanent leakage of the protected area and the temporary leakage created by door openings. Investing in improving the sealing of the protected areas will have a direct impact on running costs, as they are directly proportional to the leakage rate achieved. Typically, the payback for such improvements is less than one year. All spaces in the protected area must have split-type air cooling or closed, dedicated air recirculation systems.

To evaluate the current leakage of the area to be protected, it is recommended to perform an integrity fan test (accurately predicts the room’s pressurisation and identifies any leaks in the room), prior to any works being commenced.

Venting/Cooling
The area where the compressors and filtration units are housed is required to be well-vented in order to allow a permanent supply of fresh, ambient air to the compressors. Alternatively, the room can be cooled with chillers; this will also require a supply of fresh air. There is a requirement for a small drain in the machine room for the wastewater of the condensate cleaner.

Maintenance
The oxygen-reduction fire prevention generators are highly reliable passive units that can operate for decades with proper maintenance. This normally includes, as a minimum, changing the filters after every 3,000 operating hours or at latest after 12 months. This cycle applies if the supplied fresh air is compliant with the required quality. If the air quality is lower (in the event of dust, humidity, temperature etc.) the cycle of filter changes needs to be reduced. The compressors require regular maintenance with a cycle of 2,000 running hours.

Inspections

  • Acceptance test
    The operator/operating company must subject the oxygen-reduction fire prevention system to an acceptance test by a qualified person after installation or after any significant modification to the system. This test must take place prior to commissioning.
  • Regular Inspections
    The operators /operating companies must have the proper function of the oxygen-reduction fire prevention systems tested by a qualified person at least once per year. Special operational circumstances may make it necessary to carry out more frequent inspections.
  • Record of Inspections
    The results of the inspections must be recorded in an inspection report. The records of the acceptance tests must be kept throughout the operating time of the oxygen-reduction fire prevention system. The records of the regular inspections must be kept for at least four years. These may be stored on computer data carriers. The documents must be presented to the competent supervisory authorities upon request.

Limitations on Installation
Oxygen-reduction fire prevention systems should not be installed for use in areas where:

  • Sufficient infiltration control cannot be achieved.
  • An alternative source of oxygen is present.
  • Oxidizing agents exist that have the potential to reduce oxygen concentration by chemical reaction (for example, chlorine).
  • Substances or processes exist that evolve gases capable of modifying the atmosphere such that the oxygen concentration is reduced (for example, toxic displacement).

Benefits of Oxygen-Reduction Fire Prevention

  • Certainty of avoiding the outbreak and spread of fire.
  • Continuous fire prevention without any interruption; no refilling or replacement required.
  • Straightforward installation process compared with a sprinkler system or a traditional fire suppression system.
  • Very small footprint and little building space required.
  • Environmentally friendly – no chemicals used.
  • Simple to install and maintain.
  • Easily installed into existing premises as well as newly built spaces.
  • Retaining access to protected areas at any time.
  • Scalable to fit any sized area, large or small.
  • Slows oxidation and reduces deterioration of materials, equipment, documents and artefacts.

Oxygen-reduction fire prevention systems provide unmatched fire safety and achieve the ultimate goal in fire protection – fire prevention.

Martin McGettrick is ARA General Manager Special Hazards

Martin McGettrick is ARA General Manager Special Hazards

For further information, go to www.arafirepass.com.au 

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