5 Ways to Optimize Data Center Airflow Efficiency

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There are myriad ways to improve the energy efficiency of your data center. Many, like immersion cooling, are expensive and complicated to implement.

A much simpler and effective way to reduce data center energy costs is to improve the efficiency of airflow. The more easily air can move across the equipment inside your data center, the more effectively traditional HVAC systems can keep the equipment cool.

With that reality in mind, here's a look at practical steps for optimizing airflow inside data centers.

1. Seal Leaks in Your Equipment

We'll start with what is probably the most obvious way to improve airflow: sealing up leaks that allow cold air to move in directions that are different from where you want it to flow. If you're trying to cool down a server cabinet, for example, holes or gaps on the outside of the cabinet could reduce the efficiency of air-based cooling systems.

You probably can't close up every gap or hole; some are inevitable due to requirements like having to run cables into your equipment. But to the extent possible, find and fix leaks to improve airflow efficiency.

Related:What Is Data Center PUE? Defining Power Usage Effectiveness

2. Target Air at Data Center Equipment

Another simple but critical way to improve airflow is to make sure that your cooling systems target the equipment you want to cool. Rather than filling up your entire data center with cool air, or blowing it in the general direction of your servers and other heat-producing equipment, aim cold air sources as directly as possible at the equipment you want to cool.

Implementing this strategy may require running more duct work and possibly installing additional HVAC equipment in order to move targeted air over longer distances. But the upfront costs will be well worth it if they translate to better energy efficiency.

3. Install Higher-Capacity Fans to Distribute Cold Air

Even if you're already effectively targeting cold air within your data center, increasing the capacity of the fans or blowers that move chilled air can improve the efficiency of airflow.

Higher-capacity fans require more power to operate, of course. But the electricity required to spin a fan is much smaller than that required to chill air. That means that, if more powerful fans allow you to distribute cool air more efficiently within your data center, you'll achieve greater overall energy efficiency.

Related:New Tool to Measure and Improve Data Center Energy Efficiency

The caveat here is that higher fan capacity doesn't help much if your cool air is already being distributed effectively, or if you're blowing around room-temperature air instead of chilled air (in which case the electricity costs of the fans may exceed the efficiency savings of distributing air more effectively). It's also important not to think of higher fan speeds as a cheap fix for poor airflow efficiency situations; it's better to address the root causes of inefficient airflow than to buy bigger fans. But when combined with other measures to optimize the use of cold air, higher fan speeds can provide a boost to help ensure that air flows in the most effective way possible within your data center.

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4. Have Server Cabinets Face One Another

The rear of server cabinets is usually the place where the most heat is generated. This makes it difficult to cool servers in an efficient way if the back of one server cabinet faces the front of another. In that scenario, you end up blowing cold air down aisles of servers where one side of the aisle is hotter than the other (because one side is composed of the backs of the cabinets), leading to lower overall airflow efficiency.

A better method is the so-called hot aisle/cold aisle configuration. Under this approach, data center operators set up server cabinets in rows where the front of one row faces the front of another row — and, by the same token, the back of each row faces the back of another row.

That way, you can target the highest volumes of cool air down the aisles where you have server cabinet rears on both sides and can use the air to greatest effect. Front-facing aisles can receive less air because they have less heat to dissipate.

5. Box in the Air

To achieve the greatest possible airflow efficiency in a data center, ensure that air never flows where it shouldn't.

This means, above all, installing barriers above server cabinets to ensure that all air flows across the servers, not into the empty space above. You should also seal off any other parts of the data center, such as storage or staging space, that don't contain IT equipment, so that precious air is not wasted in those areas.

In other words, your goal should be to create a box around the equipment that needs to be cooled and restrict airflow to that box.

Conclusion: Making the Most of Your Airflow

Almost all data centers rely at least in part on flowing air to prevent IT equipment from overheating. But some data centers do this much more efficiently than others. To make the most of your airflow, ensure that you root out inefficiencies that could cause air to end up in places where it's not needed, while also taking steps to direct air at the locations where it will have the highest impact.