The FireFight products are good. I originally installed a Cold Fire system in my coach's engine bay. See RV Fire Safety
for details on this and general fire topics. I purchased my system from Mac The Fire Guy (www.macthefireguy.com
) but he now handles the FireFight products because Cold Fire got really expensive. Mac is an industry professional and I just sat through his seminar at the Indianapolis FMCA convention and continued to learn even more.
I went with a large tank system with a dash mounted warning device. I figure that if something happens the system will deploy and give me an instant alarm. That should give me plenty of time to pull over and shut down. Engine bay fires generally keep getting fed by fuel or hydraulic oil unless you shut down the engine and stop pumping fuel. The bigger the tank, the more time you have. I then can decide whether to attack it with a hand held extinguisher (assuming it's still burning) or bail out with a few things and watch it burn. Without the warning device, this units don't stand a chance. They'll expel their retardant and the fire will keep burning. By the time you notice it, it's too late.
Mac gave some interesting statistics. I forget the exact numbers but engine fires on diesel pushers are the number one cause. Both fuel and hydraulic oil are under high pressure and a leak causes the fuel to atomize quickly. Once it hits the hot turbo it ignites. The second biggest cause (and number one on a front engined gasser) is refrigerator fires, most notoriously the larger 12 cu ft fridges, such as the 4 door Norcold. The cooling units are filled with ammonia and if they leak, hydrogen gas gets out and it's the Hindenburg all over again.
Contrary to popular belief, you don't need to be running on propane to ignite. The electric element will ignite the gas just as well. Last on the list are fires caused by faulty electrical wiring, which usually rubs through and shorts out.
The Aqueous Film Forming Foam (AFFF) extinguishers are the best choice for an RV application. Both automatic units, such as FireFight's compact unit for behind RV fridges or larger engine compartment units, as well as handheld units are the perfect fit. Foam units also don't need to be "whacked" every now and then to make sure they don't cake up, unlike dry chemical extinguishers. They also don't cause a messy, corrosive cleanup once deployed.