I had previously posted about this subject here: http://itmanager.blogs.com/notes/2004/03/fire_suppressio.html
Met with a rep of Ansul and a sales tech from the local Ansul authorized dealer in the area last week. They talked to us about the two systems that they install most, Inergen and Saphire.
Saphire was talked about in a comment in by Mark Koskela in the previous post. But here's some more tidbits about it. It's a liquid at room temperature that turns into a gas with very little energy added. It's stored in the same metal canisters as FM-200 or FE-25 but is pressurized with Nitrogen, whereas the other products are turned into a liquid by pressurizing them so they don't need the Nitrogen. It turns into a gas when it hits the nozzles (the energy of hitting the nozzles is enough to turn the liquid into a gas). Pretty neat stuff. The Ansul rep poured a bit of it on our wood table and just rubbed it around with his hand for a few seconds and it evaporated quickly leaving no residue. He poured it on paper and showed how it doesn't react with the paper or ink at all. Poured it directly onto his laptop. Great demo that can only be done with this product as all the other products are gas at room temperature and pressure. Saphire or Novec 1230 works the same way that FM-200 and FE-25 work but has much less environmental impact. It basically has the same global warming potential as CO2 whereas the other two chemicals have global warming potentials over 3500 times that of CO2. Also less toxic. It's used in concentrations 50% below what is known as the no observable adverse effects level (NOAEL). FM-200 is used at concentrations right around its NOAEL and FE-25 is used in concentrations actually above its NOAEL.
The other system, Inergen is a mixture of Argon, CO2 and Nitrogen. It works by pushing the concentration of Oxygen in a room below the point that can sustain a fire. It's more expensive to install an Inergen system because it takes more tanks per room, but unlike the other three agents I've talked about, Inergen can be piped over much longer distances, so you can have a room full of tanks in a central location that can be used to suppress a fire in many different locations in a building. Also, it's much cheaper to refill an Inergen system after a discharge as they basically give the gas away for free and just charge for the labor it takes to refill the tanks. The other agents cost about $30 per pound to refill and considering that a typical room needs more than 200 pounds of the other agents a discharge can be very expensive. According to the rep, an Inergen system costs about 10-15% more to install than the other three.
Some other plusses of Inergen: With the other systems, the chemicals used are heavier than air and tend to disperse out of a room fairly quickly. This means that work has to be done to a room to make sure that it is "air tight" enough to keep the agent in place for a specified amount of time. The gases in Inergen are similar in weight to air and do not tend to disperse from a room quickly, so less work needs to be done to make sure that the room is sealed well. Your local fire marshall might have issues if you use the chemical agents in a room with open plenum false ceiling for instance whereas with Inergen they will not have the same issues. This is because rooms where FM-200, FE-25 or Saphire are installed have to pass a test where they blow air into the room with a fan and measure the air pressure. The pressure has to get to a certain point in order for the room to pass. Rooms where Inergen are installed do not need to even have this test performed.
So basically if you want an agent that is entirely benign to the environment and have a room that fits the profile for an Inergen system, it's the system of choice. Apparently, most of the systems being installed in Europe these days are Inergen systems. Unlike in the states, Halon has been banned for use in any existing system as of last December.
This is unlikely to occur in the states anytime soon, however, as the largest user of Halon in the US is the government.
Anyhow, for companies that are environmentally conscious yet still need proven fire suppression systems, it seems like Saphire and Inergen are the two systems of choice.
As a side note, FM-200 and FE-25 were both initially developed by Dupont. Dupont didn't see a market for FM-200 and sold the licensing rights to Great Lakes Chemical. The Dupont chemical is actually called FE-227ea and FM-200 is a brand name owned by Great Lakes Chemical. Dupont now sells the same chemical under their name of FE-227ea. FE-25 is only made by Dupont and only sold in the US by Fike. Because of its apparent toxicity, it hasn't been adopted widely. Saphire or Novec 1230 was developed by 3M.
BTW the detection systems and delivery hardware are the same for all 3 systems. The difference in the delivery hardware is number of tanks needed and number of nozzles needed in a given room to discharge the gas evenly to all parts of a room in 10 seconds. Inergen uses more nozzles to soften the pressure of discharge at each nozzle to prevent damage to surrounding equipment and assets.