Engine Bay Fire Suppression System

Thank you for the replies and comments. Wiki can be very sensationalist and mislead. I am happy to comment on the HF point as I am a chemist with a degree in Chemistry and a masters degree so here goes:

This clean agent is SAFE FOR OCCUPIED spaces, in that it is used where personnel will be working in the area that the fire could start. Nobody will obviously be in the engine bay when this activates but even so European Law states that this fire suppressent can be breathed with no adverse effect. As with all chemicals (plastics, petrol, foam and powder extinguishing media) they produce toxic by-products this is the decomposition process, it is all about the level of these by-products. By its very nature fire is a decomposition process. The clean agent is approved for use in European countries is Zero ozone depleting and is a halon replacement gas.

This agent is approved for use in Class B fires and fully tested to CE standard. Class B fires are those of flammable liquids such as petrol and the temperature of the petrol burning is relatively low compared to other accelerants. The temperature of decomposition is in excess of 700 degree centrigrade, the gas leaves the nozzle at minus 16 and then rapidly flash evaporates. The process of extinguishing fire can be explained below from a research paper (ref international journal on engineering performance based fire codes - Choy and Fong):

Fire is the physical manifestation of a series of high
heat-releasing chemical reactions between fuel and
oxygen. To sustain the burning process, sufficient
heat generated must be fedback to the fuel surface to
get sufficient fuel vapors for combustion. Also the
amount of oxidizer should be sufficient. The
extinguishment of fires has traditionally been
attributed to three actions: removal of heat, the
physical separation of the fuel and the oxidizer, or
the removal of the oxidizer. Thermal feedback
would be reduced if heat is absorbed by external
agents. Introducing sufficient amount of agent into
the fire gases would reduce the flame temperature so
that the flame cannot be sustained [1].
For heptafluoropropane, the contribution of physical
mechanisms to the extinguishment of fires
predominates over the chemical mechanism. It
suppresses fires primarily by extracting heat from
the flame reaction zone, reducing the flame
temperature below that which is necessary to
maintain sufficiently high reaction rates by a
combination of heat of vaporization, heat
capacity, and the energy absorbed by the
decomposition of the agent. Oxygen depletion plays
an important role in reducing flame temperature.
The energy absorbed in decomposing the agent by
breaking fluorine bond is quite important,
particularly with respect to decomposition
production formation [2].

The chemical contribution to flame extinguishment
which arises from the thermal decomposition of
small amounts of heptafluoropropane in the flame
and form fluorinated fragments such as CF3 and CF2.
These will then consume the key combustion
chain-propagating species H and O, but to a lesser
extent on OH radicals. The rates of chain-branching
combustion reaction will decrease, the chemical
flame is inhibited and the flame propagation is
halted [3].

At the temperatures and time elapsed for the fire to be extinguished the level of decompositon HF will be minimal and as this is EC approved is within any level that will cause risk to health.The rapid cooling caused by the gas will ensure that production of HF will not occur, as calculations ensure that the flame will be extinguished.

This clean agent gas is safe for use within occupied spaces, the level of Carbon dioxide, carbon monoxide and decomposition agents from the petrol will far exceed any potential hazard from the gas. This agent is used in Museums that house priceless objects, the decomposition agent as with all MSDS has to be listed, although the potential levels are going to be ppm. A MSDS (material safety data sheet) must be provided with all chemicals that are beign transported. If the vehicle carrying the gas was to be involved in an accident then the authorities need to know the risks. Or if the factory producing the gas was to explode for example that is when the presence of decompostion agents needs to be considered. In our case the fire will be extinguished almost immediately so decomposition agents such as HF are unlikely to be present.

The system as required under USCG rules contains a stall agent so the engine will be stalled so preventing any smoke or gases being blown into the cab. The recommendation after the fire has been extinguished is to wait several minutes for the gas to disperse. This is common sense as noxious gases and fumes from the burning petrol or plastic hoses etc will be in the air at significantly higher levels than any decomposition agents from the HFC-227ea.

Below is a link to the corporate Fireboy USA video that shows how effective this system is and the approvals it carries, sorry for the cheesey nature of the video:

http://video.search.yahoo.com/video...System&c=1&sigr=12l3v26lo&age=0&fr=moz35&tt=b

Regarding the airflow issue I am confident that the displacement pressure and the fact this system is EC approved to protect 0.70 cubic metres and our engine bays are half that, will extinguish the fire. We all know the research that shows a venturi effect over 50mph from the splittie vents and even with the bay vents the air being forced into the area is relatively minimal.

Agree regular inspection and testing extinguisher systems is critical that is why our system as a LED as standard for total peace of mind. The two hand helds that failed were in the green and the loop I installed did not have a LED option as had no pressure switch. So our system has been designed to address the issues and shortcomings of other products on the market. Agree any sytem could leak, this system does not have a loop so potential has been reduced. As stated if it does leak within 3 years you call me and I supply you on exchange a brand new replacement. At NO COST to you, that is my commitment to this product. The sister UK Fireboy company fill the cylinders and are fully accredited and I have carried out an audit of their customer concerns. The system we are employing has no record of failure over the last 7 years.

In conclusion this system is EC approved and the clean agent gas is safe for use in occupied spaces, the displacement pressure will create a positive pressure in excess of the airflow inlet pressure and flood the engine bay. This has been tried and tested in engine rooms with massive forced air cooling far in excess of the airflow in our VW engine bays. You can see from the video that the system goes off with a massive force of pressure. Scaling down from the massive engine rooms of Fuel tankers that carry 200 personnell to the system we are supplying is valid.

I gave my email address for people who may want further information, i am happy to provide MSDS, installation instruction and install pictures that I cannot attach to the threads.

Regards

Peter
VW Aircooled works

 

Superb reply Peter, if you read the "what's your job" thread, you'll see we're not numpties and more than capable of taking in this info.
Again, thanks for the informative answer. Good man.
I'll watch the vid now...

 

Interesting stuff

 

I bought a firetec without the warning light. I figured that if there was a fire I would know because the engine would stop due to discharge of extinguisher. After reading this I'm not sure that's the case. Should I gets warning light rigged up??
I'm very keen to do this right as I will be driving with my toddler nephew in the back and will need as much time as poss to get him out without the panic. Or with as little as poss.
I know it's probably unlikely but it's a risk I'm not prepared to take with such precious cargo. So, do indeed a warning light? Would that be better?

 

The warning light makes sense, but as it senses the pressure in the cylinder, it's probably not a simple retro fit. Best contact Firetec direct if you're bothered.

 

Interesting thread, from reading this i'm now undecided between something that goes off at a set temp or something that goes off when a fire melts a hole in a pipe. Regardless of the actual need for an extinguisher in the engine bay and the fact i have newly replaced the fuel lines (i don't however have a new wiring loom) insurance is insurance, i probably wont run someone over or hit another car but that doesn't mean i don't need it. and for the sake of a couple of hundred quid its got to be worth having.

Now can one of you jolly nice chaps at one of these automatic extinguisher companies get me a discount on my insurance for using your product?

 

Prevention is better than cure but sometimes it's nice to have a backup plan and for that reason I have a fire suppressant system fitted in my bus.

 

I'm thinking that I might go down the route of how racing cars are done, and fit a plumbed in system.... bit more expensive, but you get more gas/fire suppression that way too!!

Plus it's kinda in keeping of the whole theme of my van

 

To carry on from my previous... you can get one of these:

http://www.thermostat-muller.biz/bus-fire-control.htm

So you could connect it to a latching relay (if the electrical based system isn't) to fire off an autosport system like this:

http://www.merlinmotorsport.co.uk/p...-APPROVED-FIRE-EXTINGUISHER/product_info.html

Although, I'm sure with a bit more research I could come up with something a bit different and hook it up to a CO2 extinguisher...

 

I had one of these mounted in my MG A & MG Midget. Neither were out & out race cars but they were raced, peace of mind more than anything else. Never used in the 10 years I raced them

 

Better to have one and not need it IMO

 

The product we are currently offering in the group buy at £175 including and p&p and 3 years warranty comes with a pressure sender and dash led as standard (2 options a fireboy one or a little chrome led)

When we researched this we discovered that the worse fires were where people had jumped out the van and had electrical fuel pumps. They left the engine running so petrol was still pumping fuel into the blaze.

This system wires the fuel pump into the engine bay suppression system so if the extinguisher is activated the fuel pump automatically cuts off. Meaning that if you are in a panic you are not thinking about turning the ignition off, just getting out of the van safely.

regards
colleen
vw aircooled works

 

How can a mechanical fuel pump be wired into the system???

 

Arse - now that's working from homes, cooking Sunday dinner for the family and having a toddler trying to stick all his toys down the loo for you!!!

Sorry - My hands were working faster than my brain - I will edit it - It should say electrical fuel pump, It is wired into the negative side of the pressure sender.

A mechanical fuel pump is automatically turned off due to the stalling agent in the gas once the extinguisher is activated.

Sorry for the typo
cheers for spotting it
regards
colleen
vw aircooled works

 

Even with cutting the electric supply off to the fuel pump or stalling the engine via the gas
If the fuel pipe is ruptured before the pump then the whole tank of fuel will still drain out via gravity as the tank is higher up than the engine bay
Could the fireboy be wired to a fuel cut of solonoid fitted at the tank outlet
That way if the extinguisher fired no more fuel would come from the tank

 

You could probably do that with any system that has a pressure switch, best through a relay to keep the load on the pressure switch down if these are normally only designed to run a couple of LEDs.

 

Thought it would be useful to add that this clean gas agent is stipulated under the NASCAR regulations and must be fitted in these vehicles. The gas is HFC227ea that is in our system and it made by the likes of Dupont, they refer to it as their product FM200.

I have attached a their fact sheet showing that this clean gas agent is part of the NASCAR regulations rather than foam or powder.


If its good enough for NASCAR then I need to say little else.

http://i419.photobucket.com/albums/...vw aircooled/28-04-2013123259_zps33543d1f.jpg

 

I have spent a good deal of my former life working in computer rooms and remember seeing signs saying FM200 and never knowing what it was. The airflow in a modern computer room is massive, you have all the individual fans in the equipment moving air normally horizontally plus a very high flow through the air-conditioning system directly between the floor and the ceiling in a vertical direction. Key difference being flammable liquid versus electrical fire, however if nascar are happy with it I would be too.

 

Hi just so people are aware we are running this group offer for a further 2 weeks after Stanford Hall. Thanks to those that came to say hello and for buying systems. Great sunny day and cracking show as usual. So the last order date will be 21st May (my birthday) thanks

 

Hi

As we are still getting enquiries on regular basis we will run the group offer until after Stonor Park so people can chat face to face.

We will be trading at Stonor, jointly with my wife so look out for the orange and black Cafe De Circe Gazebo and our yellow/white splittie.

Lots of people want to see it in the flesh before they buy so only fair to run it until after Stonor. Mention the forum and you will get forum price on the standard and deluxe systems. We also are show casing our carbon monoxide 12 Volt direct wired detectors and a snazzy solenoid cut off propane/butane/CNG gas detector, cuts of the gas if the sampler detects a leak.

look forward to seeing you, cheers
Peter