Don Dunbar wrote:

Hi all,
Halon would work only if you close all air in and out of the engine bay before you fired the system of. The weight would have to be
considered as you may need 2 to 3 lbs. plus the container and associated valves and control system.

Don,
I don't think that Virg was asking about using halon as an in-flight extinguisher.  It's difficult to tell, but I am assuming that is
what you are addressing.  By "engine bay" you mean the under hood or cowling engine compartment, correct?  And furthermore by "close
all air in and out" I infer the car or aircraft is moving in your comment.

For non-forced-air fires (i.e. car sitting in the garage, plane sitting in the hangar), halon will work adequately.  The halon
chemical needs to reach a certain (low) concentration to be effective, but halon extinguishers can pump out oodles of halon into the
nearby area much faster than it can diffuse *IF* the air is relatively still.

For fires with a ready source of air (moving fire, or outdoor fire with a breeze), halon is a poor choice of extinguisher.  Much
better to go with a large CO2 bottle (small fires and small structural fires), a large dry chemical bottle (medium liquid fires), or
foam (large liquid fires).  The *worst* extinguishing agent for liquid fires is water.

Russell Kent

 
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