Difficult & Expensive to Install

Large Bottle Farms

Current state-of-the-art total flood fire protection systems typically comprise a bank of multiple pressurized bottles that hold the extinguishant, stored at high pressure using special thick-walled metal bottles to permit liquefication of the extinguishant, or increase the total mass stored if nonliquefied gases (such as nitrogen or argon) are used.

Valves, Piping and Engineer Required

They are released by high-strength, special purpose valves on the bottle when activated either manually or via an alarm control panel. A complex plumbing network has to be designed to transmit the extinguishant at masses required to meet precise extinguishing concentrations within a tight tolerance band of room concentration required to meet both the extinguishing and inhalation toxicity requirements, with independent capacities required for individual rooms in a typical multi-room protection scenario (such as a factory or high-rise building) using the same distribution network. This requires considerable effort and expense up front in the development of flow calculation methodologies to support the safe engineering of systems for such complex flow configurations.

Inflexible to Changes in the Room's "Free Volume"

It should be noted that the adequacy of this approach is predicated upon an accurate knowledge of the "free volume" (room volume minus space for equipment and furniture, etc.) anticipated over the operational life of the protected compartments, given changes in its contents, etc.; increased equipment placed in the room can easily result in an increase in discharge concentration beyond that which is safe for human exposure.

High-Cost Installation

The expense of using such a distribution network is also experienced when a system is installed at a customer site; complicated piping networks must be designed and installed on site with a notable labor expense; if the system is retrofitted into an existing building, significantly higher costs are incurred in tearing out existing drywall and other infrastructure.

Leak Prone with High Maintenance Requirements

Such high-pressure bottles are prone to leak, thereby requiring frequent inspection. If a leak is noted, the high pressure bottles may need to be sent to a central re-filling installation, resulting in protection down time at the customer site.

Vulnerable to Manmade and Natural Disasters

A system can be similarly disabled by a manmade or natural disaster, such as a gas leak explosion, tornado or earthquake, which can damage a piping network, including water sprinkler mains, thereby rendering a system virtually useless.

Effectiveness

Less Effective

Research over the last fifteen years has resulted in a myriad of "first generation" Halon replacements, including "clean" hydrofluorocarbons, which have been deployed in recent years.

These chemicals behave in a similar manner to Halon 1301, except their greatly reduced effectiveness in comparison (since they typically do not have the flame chemistry inhibition of Halon 1301) results in systems requiring from two to ten times the extinguishant mass and storage space, and being generally more expensive results in a more costly alternative from both an extinguishant and hardware perspective.

In addition, the increased storage space requirement for a large increase in extinguishant bottles poses a difficult placement problem for facility engineers, and a considerable obstacle for those wishing to retrofit an existing Halon installation with a bottle "farm" many times bigger than its Halon predecessor in a limited storage space.

Vulnerable to Environmental Legislation

Finally, most of these chemicals have been determined to have long atmospheric lifetimes, thereby making them subject to subsequent global warming legislation worldwide in line with the Kyoto Protocol over the next few years.

"Environmentally friendly" alternatives to the hydrofluorocarbons have been proposed and even fielded to a limited degree, but also suffer from their own design and operational limitations.