In this lesson, we're going to cover heating,
ventilation, and air conditioning systems.
Now, a heating, ventilation, and air conditioning system,
also known as an HVAC system,
is a technology designed for indoor environmental comfort
that provides temperature control,
humidity management, and airflow regulation.
In your house, you probably have an air conditioner,
and you use it to make yourself more comfortable
as you're working or you're sleeping.
But HVAC is actually much more important for our hardware
and our networking devices than it is for us the humans.
If these devices don't maintain
the right temperature and humidity levels,
they will prematurely fail, and they will stop working.
So let's take a quick look at these different areas
that you need to be considering
when it comes to HVAC systems.
First, we have temperature control.
Now, temperature control is a fundamental consideration
because our computer networks and data centers house
a significant amount of electronic equipment,
and all this equipment generates heat.
Now, without proper HVAC systems,
the temperature can quickly rise,
and this leads to hardware malfunctions
and reduced efficiency.
In fact, most of our networking equipment
actually has failsafes designed into their firmware
so the devices will actually power themselves down
if they start to get too hot
in order to prevent any damage
from occurring on that system.
Now, this is good because it protects our equipment,
but it also means our network is going to go offline
when these devices overheat,
so we have to try to prevent that.
Now, to prevent this overheating,
we should maintain a steady temperature,
typically around 68 to 77°F
or around 20 to 25°C,
for your equipment to operate at its peak efficiency.
Now, this is a general rule, but you should always check
your equipment manufacturer's recommendations
for the specific temperature and set points
that you should be using for your HVAC systems
to maintain peak performance
for all of your networking equipment.
Second, we have humidity levels.
Now, humidity refers to the concentration
of water vapor that's present in the air.
If you have too much humidity,
this can lead to condensation that'll cause corrosion
or electrical shorts inside of your equipment.
If you have too little humidity,
this will cause an environment
that's prone to static electrical charges
that could potentially damage your sensitive electronics.
Now, to prevent either of these conditions from occurring,
you really should utilize accurate humidity controls
and regular monitoring of your HVAC system
to maintain a relative humidity level of 40 to 60%.
This way, it's not going to be too low
and cause static buildup,
nor is it going to be too high and cause condensation
or electrical shorts inside of your equipment.
Third, we have to consider airflow management.
In our data centers,
we have a lot of equipment that's operating,
and all this equipment generates heat.
Now, this heat has to be managed and dissipated,
otherwise, your systems will overheat,
or they'll shut down to prevent themselves
from damaging themselves by overheating.
Now, to properly manage the airflow,
most data centers are going to use a concept
known as port-side exhaust and intake.
But you may also have heard this
referred to by its colloquial name
of the hot aisle/cold aisle configuration.
Now, the port-side exhaust and intake
is a strategic method of air distribution
in which server racks are positioned in alternating roles,
where cold air intakes are all facing one aisle,
which we call the cold aisle,
and all the hot air exhaust are facing the opposite aisle,
which we call the hot aisle.
This type of cold aisle and hot aisle arrangement
is going to maximize our cooling efficiency
by directing cold air exclusively to our servers intakes,
and pulling hot air away from the equipment
to prevent the mixing of hot and cold air streams.
This type of configuration
not only improves the efficiency of our cooling systems,
but it also helps to significantly reduce
our energy consumption.
Overall, it's really important
to consider the different HVAC factors,
such as temperature, humidity, and airflow,
when you're designing and laying out your new data centers
because it's very difficult to retrofit them
after they've been fully built out.
Make sure that you're properly spacing your racks
and orienting them in a way that leads to efficient airflow
by using exhaust and intake,
or hot and cold aisles, inside of your designs.
Also, your data centers should use raised-floor systems
so that cold air can be pushed upward into the rack
and then expelled out as hot air
through the exhaust, or hot aisle,
once it cools down your equipment
that's located in that rack.
Finally, you should also ensure
that you have ceiling plenums that are configured
to return the hot air back out to the data center
once it's cooled down your equipment.
All these considerations will help
to enhance the effectiveness of your HVAC system
and allow your network equipment
to remain healthy and error-free.
So remember, when you're planning the physical installation
of your computer networks and data centers,
it's also imperative to integrate an HVAC system
that can effectively manage your temperature,
maintain proper humidity,
and utilizes a hot aisle and cold aisle configuration
for airflow management.
These measures will help to protect your investments
to ensure uninterrupted operation
and to optimize performance of your network
and data center equipment.