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In this lesson, we're going to cover heating,

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ventilation, and air conditioning systems.

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Now, a heating, ventilation, and air conditioning system,

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also known as an HVAC system,

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is a technology designed for indoor environmental comfort

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that provides temperature control,

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humidity management, and airflow regulation.

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In your house, you probably have an air conditioner,

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and you use it to make yourself more comfortable

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as you're working or you're sleeping.

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But HVAC is actually much more important for our hardware

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and our networking devices than it is for us the humans.

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If these devices don't maintain

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the right temperature and humidity levels,

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they will prematurely fail, and they will stop working.

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So let's take a quick look at these different areas

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that you need to be considering

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when it comes to HVAC systems.

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First, we have temperature control.

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Now, temperature control is a fundamental consideration

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because our computer networks and data centers house

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a significant amount of electronic equipment,

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and all this equipment generates heat.

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Now, without proper HVAC systems,

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the temperature can quickly rise,

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and this leads to hardware malfunctions

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and reduced efficiency.

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In fact, most of our networking equipment

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actually has failsafes designed into their firmware

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so the devices will actually power themselves down

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if they start to get too hot

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in order to prevent any damage

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from occurring on that system.

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Now, this is good because it protects our equipment,

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but it also means our network is going to go offline

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when these devices overheat,

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so we have to try to prevent that.

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Now, to prevent this overheating,

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we should maintain a steady temperature,

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typically around 68 to 77°F

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or around 20 to 25°C,

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for your equipment to operate at its peak efficiency.

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Now, this is a general rule, but you should always check

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your equipment manufacturer's recommendations

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for the specific temperature and set points

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that you should be using for your HVAC systems

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to maintain peak performance

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for all of your networking equipment.

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Second, we have humidity levels.

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Now, humidity refers to the concentration

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of water vapor that's present in the air.

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If you have too much humidity,

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this can lead to condensation that'll cause corrosion

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or electrical shorts inside of your equipment.

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If you have too little humidity,

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this will cause an environment

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that's prone to static electrical charges

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that could potentially damage your sensitive electronics.

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Now, to prevent either of these conditions from occurring,

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you really should utilize accurate humidity controls

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and regular monitoring of your HVAC system

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to maintain a relative humidity level of 40 to 60%.

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This way, it's not going to be too low

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and cause static buildup,

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nor is it going to be too high and cause condensation

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or electrical shorts inside of your equipment.

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Third, we have to consider airflow management.

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In our data centers,

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we have a lot of equipment that's operating,

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and all this equipment generates heat.

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Now, this heat has to be managed and dissipated,

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otherwise, your systems will overheat,

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or they'll shut down to prevent themselves

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from damaging themselves by overheating.

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Now, to properly manage the airflow,

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most data centers are going to use a concept

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known as port-side exhaust and intake.

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But you may also have heard this

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referred to by its colloquial name

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of the hot aisle/cold aisle configuration.

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Now, the port-side exhaust and intake

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is a strategic method of air distribution

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in which server racks are positioned in alternating roles,

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where cold air intakes are all facing one aisle,

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which we call the cold aisle,

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and all the hot air exhaust are facing the opposite aisle,

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which we call the hot aisle.

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This type of cold aisle and hot aisle arrangement

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is going to maximize our cooling efficiency

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by directing cold air exclusively to our servers intakes,

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and pulling hot air away from the equipment

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to prevent the mixing of hot and cold air streams.

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This type of configuration

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not only improves the efficiency of our cooling systems,

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but it also helps to significantly reduce

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our energy consumption.

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Overall, it's really important

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to consider the different HVAC factors,

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such as temperature, humidity, and airflow,

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when you're designing and laying out your new data centers

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because it's very difficult to retrofit them

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after they've been fully built out.

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Make sure that you're properly spacing your racks

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and orienting them in a way that leads to efficient airflow

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by using exhaust and intake,

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or hot and cold aisles, inside of your designs.

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Also, your data centers should use raised-floor systems

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so that cold air can be pushed upward into the rack

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and then expelled out as hot air

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through the exhaust, or hot aisle,

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once it cools down your equipment

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that's located in that rack.

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Finally, you should also ensure

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that you have ceiling plenums that are configured

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to return the hot air back out to the data center

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once it's cooled down your equipment.

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All these considerations will help

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to enhance the effectiveness of your HVAC system

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and allow your network equipment

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to remain healthy and error-free.

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So remember, when you're planning the physical installation

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of your computer networks and data centers,

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it's also imperative to integrate an HVAC system

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that can effectively manage your temperature,

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maintain proper humidity,

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and utilizes a hot aisle and cold aisle configuration

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for airflow management.

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These measures will help to protect your investments

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to ensure uninterrupted operation

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and to optimize performance of your network

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and data center equipment.