For the several systems I know of, it has always been the local Fire Marshal/City Ordinance who determines the fire suppression requirements.

You may also want to invest in a 'dry' or chemical type of suppression system depending on what type of electronic equipment is actually in the chamber. Electricity and water don't react very well.

For most absorber material, just for grins and giggles, try setting it on fire. It doesn't burn very well. Sort of makes the whole fire suppression thing seem silly.

We had to satisfy the OSHA inspector also, but that may have had to do with the human safety element in halon.  This sort of things could involve the time it takes to egress from the crane, assuming the power goes out when the fire happens.  You have to have the workers pass whatever course is needed to go down a rope from a crane and make thei way out before the halon problem starts.

I am attempting to make this sound difficult and confusing for using halon.  

I wish you luck in planning for the worst and never having to use it.

I worked somewhere that had CO2 room flood fire prevention.

It eventually killed someone.

Thanks for the responses. I think I will build a small fire (in a metal tub with only a tiny bit of absorber).

Seems the non water solutions are more costly than water solutions - if I'm wrong on that, let me know who you recommend for installation.

I'd heard that the absorber fires, once started are difficult to put out.
As an example, while at Raytheon Goleta about 7 years ago, some geniuses piled absorber from a purchased anechoic chamber so high up in a storage area, that it was only a foot from the ceiling propane heater. First cold night, big black smoky fire, and lots of new insurance paid absorber arrived a few weeks later. So it definitely burns.

Thanks for the inputs.
Has anyone experienced putting out anechoic fires with water, specifically - just how difficult is it??

kch
PS:regarding common sheets of gray colored foam packing material, if you ever get that stuff lit on fire, it blackens the room in less than a minute with smoke. Suggest if you own a small business to try lighting a tiny piece of that on fire, then replace it all with white foam. Info compliments of another Raytheon fire in the EMI lab.

Anechoic chamber foam is basically carbon dust embedded in polyurethane foam.  The funny thing about polyurethane foam is that it releases cyanide gas when it burns.  

Halon is the agent of choice, but of course that can't be obtained anymore, but there are some other choices as well, such as Energen.  All are expensive.