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This section addresses the narrow range of fire protection applications that were served by the halons, prior to their phase out under the Montreal Protocol. The range of these specialized fire protection applications includes:

• Building fire protection, where high value equipment is involved and personal safety needs to be considered. In these situations, water or dry chemicals could damage or destroy the equipment, while halons and other alternatives can effectively suppress the fire without damaging the equipment and endangering personnel who might require a significant part of a minute to exit the space. Computer rooms and data centers are a prototypical example of this application
• Suppression of fire/explosion of flammable vapor in air, for example, in aircraft jet engines and at gasoline service stations
• Hand held fire extinguishers (streaming), where valuable equipment would be damaged by water or dry chemicals

HFCs are important halon substitutes primarily in occupied areas where space and weight are constrained, or speed of suppression is important. HFC emissions from fire fighting are approximately 0.006% of all GHG emissions.

HFC use for fire fighting represents a very small share of total use. About 50% of the previous halon uses have been replaced with not-in-kind, non-ODP alternatives. These include water-based systems, foam, dry powder, and fire-protection engineering approaches involving risk analysis, prevention steps and early detection systems combined with portable extinguishing equipment. About 25% have been replaced with non-halocarbon gaseous agents such as inert gas mixtures or carbon dioxide. Despite the consumption phaseout in developed countries, there remain some critical halon uses in existing and new applications, such as civil and military aircraft, military vehicles, and other specialized high-risk situations. Critical use halon comprises 3 - 4% of the fire fighting market. Only about 20% of the former halon market has been replaced by HFCs.

Several HFCs are currently being sold commercially for fixed fire suppression applications as shown in Table 12-1. HFC-227ea and HFC-236fa are also offered as streaming agents for portables usage.

These materials both replace halon 1301 and halon 1211 in fire protection systems. HFC growth is limited by high system cost compared to other choices.

Table 12-1: HFC Alternatives for Fixed Fire Suppression

In contrast to the refrigeration and air conditioning equipment discussed in previous sections of this report, fire suppression systems are essentially passive systems that sit idly while awaiting the mishap against which they are intended to protect. The fire detection system consumes a low level of electrical power, and small amounts of energy are consumed during periodic operating tests.

The systems are material intensive, and can include a significant amount of steel pressure vessels to store the fire suppression agent and steel piping to distribute the fire suppressant. The embodied energy in these materials, as well as the embodied energy in manufacturing and compressing the HFC or inert gas fire suppression material is the most significant energy input over the life cycle.

Emissions of the fire suppressant can be categorized as routine losses over time and releases of the fire suppressant to extinguish a fire. Routine losses include leakage and accidental discharge. Current practices hold emissions, both fire and non-fire related, to 1-3% annually of the installed base. Releases to suppress a fire in practice do not occur very frequently and currently are estimated to be approximately 1.5% of the installed bank. Over the 10 to 25 year typical system useful life, the vast majority of these systems are never called upon to suppress a fire. At the end of the useful life of a system, the fire suppressant can be recovered for recycling or reclaimed for transformation into non-GWP substances.

HFCs are extremely effective in the basic fire suppression function. Speed of fire suppression using HFCs provides inherent safety benefits.

The acute toxicity of HFC fire suppression agents has been studied extensively and a methodology has been accepted as installation guidance for system installers. The guidance allows the safe usage of HFCs in the fire protection application.

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