HVAC, Temperature, and Humidity Controls – CompTIA Security+ SY0-401: 2.7


The environmental controls in your data center are an important part of your infrastructure. In this video, you’ll learn some important considerations regarding your HVAC, temperature settings, and humidity controls.

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In a data center, you’ll see the abbreviation HVAC quite a bit. That stands for heating, ventilating, and air conditioning. And if you’re in a data center, the ability to keep the environment at a constant temperature becomes a very important thing. All those computer systems they’re all generating heat. We have to make sure that they’re running optimally. And this is not a simple thing. It’s not just you go out and buy some air conditioning and put in your data center. There’s a lot of engineering involved in being able to design this properly. It’s a very, very complex science. It must be also integrated into the fire system. Not only it this is a very complex system, just to be able to maintain the proper environment, if a fire occurs you don’t want your cooling system to circulate oxygen into the environment and make sure the fire is being fed. So that’s something that very often is all integrated together and all working together in your environment.

Your data center should be absolutely separate certainly from a heating, ventilating, and air conditioning perspective from the rest of the building. The data center gets very hot if you cooled off the rest of your organization as much as you’re cooling off that room everybody would be very, very cold. And if your people are cold, they’ll change the temperature and that means your temperature in your data center would rise. So by keeping those separate, you can really maintain the proper amount of cooling and heating. One of the problems in a data center is overheating. So you want to be sure that if something was to happen to the heating system or the cooling system in other parts of the building that your data center would still be in perfect operating condition.

These are systems called the closed-loop recirculating systems and they’re also called positive pressurization systems. You’ll see those referred to when you look at HVAC. That means in a closed-loop circulating system that the internal air within your organization is constantly being recirculated through there. You’re not pulling air in from the outside to be able to do that. And the positive pressurization means that if you open the door to your building air is going to rush out. And that’s exactly what you want especially in the case where you have air that is being filtered, you don’t want air coming inside that has not been filtered. And in the case of fire or smoke, if somebody opens the door, you would like all that smoke to go out and positive pressurization is going to make sure that everything inside of your building is going to be pushed outside whenever you open the door.

Temperature and humidity in a data center is a bit of a challenge. Your things get too hot, your systems are going to crash. Things get too cold, you’re wasting a lot of money on your cooling system. So there has to be somewhere in between that we would be able to use. If you ever walk into a data center, you’ll find many of them are very, very cold. But if you look at some of the recommendations from people like Google that has a lot of data centers, they recommend 80 degrees in your cold aisle. We’ll talk in a moment what a cold aisle is versus a hot aisle or a warm aisle. Your 80 degree temperature that’s kind of warm. But if you look at the manufacturer’s specifications for most servers and the components inside of those servers 80 degrees is just fine. That’s a temperature that will optimally work for whatever you happen to be putting in. So 80 degrees being kind of warm should be what your data center is. It’s remarkable how many data centers though are keeping things at a lower temperature. That’s something you’ll have to look at whenever you’re planning to cool your data center.

Humidity completely different thing. That’s how much water is in the air. And when your cooling systems, you’re really removing a lot of the water. So you have to also think about controlling humidity in there. If you have too much water in the air, you could corrode your components over, in fact, a very short period of time. If your humidity is too low there’s too little water in the air, you’re going to have a lot of static discharge and that’s something you really don’t want around these very, very sensitive electronic components.