We recommend with few exceptions that water sprinklers be installed in all facilities to provide structural protection. However, we also recommend that additional suppression agents and detection systems be considered for contents/asset protection.

For the structures housing sensitive electronic areas we recommend that a double interlock pre–action sprinkler system be considered. This method would require a loss of supervisory pressure in the sprinkler piping network and an electric smoke and/or thermal detection before water would be released into the protected area.

Property damage exposure in sensitive electronic areas may be as high as 50 times that of manufacturing or warehousing. Not only are the physical assets themselves of value but of greater importance are the services they may perform and support. It is imperative in such highly concentrated value areas, that a fire be quickly detected and extinguished.

From a copy of a full scale fire test performed on computer equipment in Europe using sprinklers, Halon, and CO₂. "The tests have shown quite clearly that sprinkler systems are unsuitable for protecting the false floor. This result can also be read across completely to the computer room itself. It is not possible to protect electronic equipment by means of automatic water extinguishing systems. Their value for protecting buildings, however, remains undisputed."  

Because Inergen is stored as a gas, it cannot be discharged to achieve rapid buildup of total flooding concentration. Discharge times in excess of one minute and as long as three minutes have been noted. Additionally, because Inergen is stored as a very high pressure gas, as opposed to FM-200 which is stored as a liquid, its storage efficiency is low. Substantial numbers of containers are necessary to store enough Inergen for even the smallest hazards. The additional floor space required to accommodate the numerous Inergen cylinders along with added service costs to maintain, weigh and check all these cylinders must also be considered.

Carbon Dioxide suppression systems are another clean agent alternative to Halon. When released the stored pressure acts as a propellant. Normally, there is about 21% oxygen in air. The addition of CO₂ reduces the oxygen content to a point where combustion cannot exist and the fire is literally suffocated. As with Inergen, however, life safety consideration must be heavily weighed. NFPA does not recommend total flooding CO₂ systems in normally occupied spaces unless arrangements can be made to ensure evacuation before discharge. The same restriction applies to spaces that are not normally occupied but in which personnel may be present for maintenance or other purposes. Evacuation can be difficult once the discharge starts because noise, greatly reduced visibility, and the physiological effects of the carbon dioxide concentration may confuse the occupants.

Other technical difficulties relative to temperature and humidity can arise with the release of carbon dioxide. When released, this agent is very cold and will cause a sudden drop in the temperature of the room. Some sensitive electronic equipment is limited to a maximum change of 15 deg. F (9 deg. C) per hour. Concurrent with a rapid drop in temperature will be a rapid increase in the relative humidity. Experimental evidence shows that the dew point can be reached quickly, causing condensation to form on many equipment components.

FM-200, chemically known as heptafluoropropane is a clean agent alternative to Halon 1301 which NFPA 2001 accepts for use in total flooding situations where human exposure is expected. FM-200 contains no ozone depleting chlorine or bromine. Additionally, it has a very low GWP (global warming potential) of 0.7 and an atmospheric lifetime of 17–31 years. This is the shortest atmospheric lifetime zero-DP new clean agent available.

In assessing the toxicity of halocarbon alternatives, the EPA is primarily concerned with consumer and worker exposure during a fire. The principal guideline is cardiac sensitization which is defined as increased susceptibility of the heart to adrenaline which may result in potentially fatal heart arrhythmias. Two terms, NOAEL and LOAEL, are used in evaluating cardiac sensitization. NOAEL is the No Observed Adverse Effects Limit when dogs are subjected to a predetermined concentration. LOAEL is the Lowest Observed Adverse Effects Limit and is the lowest concentration where at least one dog has begun to experience cardiac sensitization. The criteria for human exposure in alternative total flooding agents is judged on these two terms as to suitability for a normally occupied space. This also comes into play since the EPA is adopting the OSHA Standard CFR 1910.162 which limits the exposure to an agent based on the length of time it takes to evacuate the area.

FM-200 has a low toxicity. It is an acceptable substitute for Halon 1301 and is currently listed by U.L. in systems. It has a NOAEL of 9% and a LOAEL of at least 10.5%, while it’s design concentration is 7%. Therefore, it can be used in normally occupied spaces.

FM-200 is a low pressure gas and can be housed in cylinders similar to the traditional Halon 1301 equipment. The concentration requirement of 7% by volume avoids any concerns of enclosure over–pressurization which must be carefully considered with the installation of Inergen and carbon dioxide.

With a discharge of FM-200 suppression agent, total extinguishing concentration is reached in approximately 10 seconds.

  FM-200 is life supporting within design concentrations and has been found to be electrically non–conductive and safe for use on electrically charged equipment. The relatively high boiling point of FM-200 reduces the danger of thermal shock to delicate electronics that might possibly occur from the direct discharge of other agents such as CO₂. The Environmental Protection Agency has stated that "FM-200 does not deplete stratospheric ozone and that it is the most effective of the proposed substitutes for Halon 1301".

Our recommendation for conventional smoke detection for sensitive electronic areas consists generally the combination of photoelectric and ionization principle smoke detectors. The photoelectric smoke detector is normally most responsive to fuels whose products of combustion are best defined as cool smoke. This type of smoke characteristically accompanies plastic type materials. Therefore when a raised floor is utilized we recommend that photoelectric detectors be exclusively used in the sub floor. These detectors are most responsive to the cool type wiring/plastic fire that would be anticipated and they are very stable in high air flow areas. The ionization detector is most responsive to fires that typically are associated with hotter and/or flaming combustion such as paper. Because we do not know whether we are going to have a plastic or a paper fire depending upon the fire loading/contents we recommend that the ceiling be protected with both ionization and photoelectric detectors. Special emphasis must be made to strict adherence to the manufacturers and the NFPA No. 72 spacing requirements especially when high air flows are involved. An alternate and preferred method for many areas may be the use of an air sampling type system. This detection generally is up to 1000 times faster than conventional smoke detection however despite its high sensitivity it is a very stable and reliable detector. Unlike conventional detectors that are static devices that must wait until the smoke comes to the sensor. The HSSD air sampling device actually draws air throughout the system. This sensor is relatively unaffected due to high air flow and stratification affects which typically reduce the sensitivity of conventional detectors.