[yholio]

The problem with water in the same place with high power equipment is that it instantly turns the room into a death trap for any personnel, now everything is potentially live.

Also, in the first part of a lithium battery fire, dropping water on them is quite explosive. It will eventually quench the fire but on the short run it will make it worse, filling the room with explosive hydrogen and poisonous lithium hydroxide. So when your water sprinklers engage over your UPS, you better be sure there's nobody around: https://www.youtube.com/watch?v=cTJh_bzI0QQ

[throw0101a]

> The problem with water in the same place with high power equipment […]

Most high-end UPSes have a relay where you can run an active-high or active-low emergency power off (EPO) signal. The EPO can either be a button that is pressed manually by the staff, automatically via fire suppression system, or both/either.

Schneider-APC white paper (PDF)

* https://download.schneider-electric.com/files?p_File_Name=AS...

The EPO can also cut-off the HVAC so oxygen is no longer fed into the area, and smoke isn't (re-)circulated.

In the US, this is probably covered in NFPA 75, "Standard for the Fire Protection of Information Technology Equipment":

* https://www.nfpa.org/codes-and-standards/all-codes-and-stand...

[gmueckl]

Such a switch doesn't make any remaining battery charge in the UPS go away magically. If the UPS housing gets breached (e.g. ingress of impure water or bending/melting from heat), you're back to square one.

[throw0101a]

Batteries can be held in a different room than the IT equipment and UPS inverters--up to 200m per the manual of the APC Galaxy VX.

So can have the more common water fire suppression in the day-to-day areas where people are more likely to be in, and have have non-water solutions. Water mist instead of 'traditional' sprinklers is also a thing in many places:

* https://res.mdpi.com/d_attachment/energies/energies-13-05117...

[walshemj]

You would not be using water here

[jacquesm]

You would be using Halon injection in a normal DC, after sufficient warning to employees to gtfo if they hadn't done that already.

[fanf2]

Not halon any more, but instead an ozone-friendly fire suppression gas such as argonite

[Dylan16807]

That's basically true but I want to note that halon is a gas that actually suppresses fire while argonite is just there to get rid of oxygen.

[fanf2]

Yes, one of the big differences between the old halon system we got rid of many years ago, and the newer argonite systems, is that the argonite requires many more gas cylinders, because (as you say) argonite works by getting rid of oxygen, instead of chemically suppressing combustion. The small machine room in our office building was refitted about 8 years ago with argonite fire suppression, and they had to add pressure release vents between the machine room and the outside so that there was somewhere for a room full of air to be displaced to.

AIUI being in a room during a halon dump is unpleasant but not too dangerous, but you really don’t want to be in there when the argonite release happens!

[jacquesm]

Thank you! Totally missed that Halon was 'out'.

[ArchOversight]

Halon is not really created anymore. If you have an halon fire suppression system the only way to get recharges is to get it recycled from other systems that are no longer using it.

It's fun when someone accidentally dumps the halon system because they pressed the wrong button, and now halon has to be sourced for replacement.