Operating a data center is a huge undertaking that requires a lot of planning and effort to handle properly. One of the most important things to look into is the data center airflow management plan. Shockingly enough, according to a 2015 survey, as much as 24% of a data center’s budget can go into cooling. This is largely because of inefficient airflow management strategies.
Data center managers often make the mistake of simply adding more cooling capacity when their facility becomes too warm. While this will keep the data center at proper temperatures, it is not the correct way to handle this. A well thought out airflow management plan allows the facility to remain at the proper temperatures while also saving a lot of money due to lower cooling costs.
Hot Aisle | Cold Aisle
Planning the airflow of your data center starts with a concept known as Hot Aisle | Cold Aisle. This is a strategy that has been in use since 1992 when IBM first developed it. A Hot Aisle | Cold Aisle layout occurs when the server racks are positioned so that the front of one row faces toward the front of the next row. Then in the next aisle, the back of both sides face each other.
This is done so that the aisles that face the front of the racks will allow the equipment in the racks to pull in cool air. On the other aisles, the heat from the equipment of both rows of server racks will blow out.
When a data center doesn’t follow this strategy, the warm air from one row starts to warm up the cool air that is pulled in by the equipment in the next. This is less efficient than keeping the cool air in the ‘intake’ aisle and warm air in the ‘exhaust’ aisle.
Physical Barriers Between Aisles
Setting up the server racks as described above is a great start toward the hot aisle | cold aisle strategy. Server racks, however, don’t typically go up to the ceiling, so without a little extra effort, the hot and cold air will mix when it passes over the top.
Installing physical barriers between aisles can prevent this problem. There are a number of different options to accomplish this goal. There are also options to place barriers at the end of each aisle to further contain the air.
Forced Air from Raised Floors into Cold Aisles
The cool air from the facility’s chillers needs to enter the data center through a raised floor using grated panels. Having the grated panels feed up into the cold aisles will ensure there is a constant supply of cooled air that can be pulled in by the equipment within server racks. Since the air coming up through the floor will be directly from the chilling units, it will be as cold as possible, allowing it to cool equipment very efficiently.
Exhaust from Top of Hot Aisles
In the warm aisles, proper airflow management demands that you take advantage of the fact that heat rises. This means having the data center exhaust vents located in the ceiling above the warm aisles. As the equipment within the server racks push out the warmed air, it will quickly travel up through these vents and be discharged either outside or circulated back through the cooling system, depending on the chiller setup.
Properly Set Up Server Racks
In addition to setting up a warm aisle | cold aisle configuration, you need to make sure your server racks are set up correctly to maximize airflow. Having an airflow plan within server racks will not only make the overall airflow strategy more effective, but it will also ensure all your equipment is able to operate at their ideal temperatures.
These are some key points to take note of when creating the perfect airflow management plan within server racks:
- Position the Equipment Properly – The most important thing to focus on is installing servers and other equipment so that the intake vents are facing toward the cold aisles and the exhaust fans are pointing out toward the warm aisles.
- Filler Panels – Server racks are designed to operate with equipment in every bay of the rack. If you don’t have the rack filled, you will want to install filler panels (also known as blanking panels). This will keep the air flowing properly and avoid any hot spots. Filler panels have several other benefits beyond airflow as well.
- Proper Doors – There are several types of doors that can go on server racks. Choosing the right one for your airflow plan is critical. You can choose glass doors, which will allow warm air to flow up and out of the rack. A more popular option, however, is vented doors that will allow cool air to flow in the rack and warm air to easily exit.
- Additional Fans – The equipment within server racks will typically have fans used for cooling. In many situations, this is sufficient for promoting airflow within a rack. If you need to increase the airflow rate, however, you can install additional fans to either suck cool air in or blow warm air out in the direction you desire.
Closely Monitor Temperature
A good data center airflow management plan is a great way to keep your facility at the right temperature. To help ensure your plan is always providing you with the results you need, it is essential that you set up thermometers throughout the facility, so you know the temperature in every location. This will alert you to any problems before they cause any damage. Advanced systems will allow a computer system to monitor the temperatures in real-time so alarms can be triggered should any section of a data center have a temperature spike.
With proper planning and monitoring, your data center’s airflow helps keep all your equipment operating at the right temperatures. It will also help to keep your cooling costs low, so your company isn’t wasting money on an inefficient plan. One last point is to make sure you are constantly evaluating your airflow plan to ensure it is always providing you with the results you need.