When considering fire suppression,
we are thinking about if a fire does get started,
what are the three things that it needs to survive?
The first thing is oxygen, fuel, and then heat,
which is a bit ironic sounding, sort of like we need life to have life,
but yes, a fire needs heat.
And if, in fact, you can go after that element of survival,
you can actually suppress or stop a fire.
On the other side is what can be used for detection.
Seeing the fire would be using flame detection.
Here,
it is a photoelectric eye that is sensing the infrared heat from
that fire or visible and ultraviolet light that may come from the
fire that changes the dynamics of the room.
Smoke detection uses ionization and photoelectric capabilities.
In other words, it's the particles that come from the burn off.
And then heat detection is all about the rate of rise of temperature.
This is the original way of being able to detect a fire.
For putting fires out, there are a number of different agents that could be used.
Gaseous agents is an example, like FM‑200,
which is a colorless, liquefied, compressed gas.
It's stored as a liquid and dispensed into the hazard as a colorless,
electrically non‑conductive vapor that is clear and does not obscure vision.
Argonite is another example of an agent that could be used in order to put a
fire out and possibly suppress it from being able to start,
along with Aero‑K, foam, and yes,
we still have water as a means of being able to put fires out.
If you are in a municipality that mandates the use of water for putting
the fire out as a primary agent within a building,
then there is some need to do some remediation.
One of the remediation steps is to use what is called dry‑pipe.
Here, as pictured, the water is not filling up the whole pipe.
There is something that prevents the water from going all the way
out to the end of its expression capability,
and that may be the part that's actually hanging over the
sensitive equipment inside the data center.
Along with this, you would possibly also have some kind of pre‑action.
One of the elements of pre‑action is a timer. That way, the human
could actually get involved and say you know what,
that's not a fire, and even though the warning is telling us that it's a fire,
there may be a delay before the water is actually expressed.
Once the fire is actually allowed to be detected and those who have
manual override are wanting to escape from that fire,
the pre‑action time will expire and then the dry pipe will release the water.
On the way out of the facility,
those who are escaping may have a button that they need to
push called an Emergency Power Off button.
This does an ungraceful disconnection of the power serving into the server room.
Think of it not only as a way of stopping the power going to the UPS system,
but also stopping the power coming from the UPS
systems into the data center equipment, therefore,
making it less likely that those having to escape a fire don't
have a worse day in getting electrocuted.
Next, we're going to take a look at the heating,
ventilation, and air conditioning under design resilience.