Raised Floors

[Paul Berger]

On 2019-05-22 10:00 a.m., Paul Koning via cctalk wrote:
>
>> On May 22, 2019, at 6:57 AM, Stefan Skoglund via cctalk <cctalk at classiccmp.org> wrote:
>>
>> ons 2019-05-22 klockan 08:45 +0000 skrev Wayne S via cctalk:
>>> ...
>>> Funny, but Halon is outlawed and having it around did seem to bother
>>> them. It was replaced with some other gas system that i can't
>>> remember the name.
>>>
>> It is a gas bottle with gas under pressure - they dont like getting hot
>> they become explosive in that case.
> Nitrogen.  I remember seeing an installation with a whole row of compressed nitrogen bottles, looking a lot like a row of welding gas tanks.  It came with major warning signs about the danger to personnel when it goes off.
>
> I think Halon is far less dangerous because it doesn't just work by displacing oxygen, though the details escape me.
>
> 	paul
>
It was reputed that you could breath the halon making it easier to exit 
the room.  One of the big dangers from halon discharge in a room with a 
raised floor was the under floor nozzles would fling floor tiles up into 
the air and also raise a lot of dust.  A coworker that was in a room 
during a halon dump broke a leg falling into the hole left by a 
displaced tile while running for the door.  Most flooding systems gave a 
warning alarm before they actually discharged and had an override so 
that the automatic system could be stopped.  I was never in a room 
during a discharge but I have seen video of it.  I have also heard 
stories of it displacing enough floor tiles to affect the stability of 
the floor leading to a collapse of the floor supports and all the 
equipment ending up resting on top of cables and everything else under 
the floor.

Previously there where comments made about plumbing under the floor, in 
my experience it was pretty common for water cooled equipment and also 
for air conditioners that used chilled water for cooling.  The current 
water cooled systems I am familiar with have a coolant loop inside the 
rack that includes heat exchangers that  is separate from the building 
chilled water supply.  Inside the machines there are "water" blocks in 
direct contact with CPUs and memory and also sometimes the back door of 
the rack has a heat exchanger built into it.  Hot air exits out the back 
and is cooled by the back door the intent is to reduce the load on room 
air conditioning.

Paul.

Halon was banned because it was implicated as one of the chemicals that 
damaged the ozone layer.  I recall one customer that had a CO2 flooding 
system