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How to Eliminate Data Center Hotspots

Careful temperature control is essential for protecting data center equipment from harm. Because they process enormous quantities of data daily, servers and other units expel high volumes of hot air.

If managed poorly, this massive workload can lead to hotspots, which can severely damage equipment and spike your energy costs. This post discusses everything you need to know about hotspots, including how to find, eliminate, and prevent them from appearing in the first place.

What Are Data Center Hotspots?

Data center hotspots are areas where the server input air exceeds 81°F (27°C), according to the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). They typically appear at the tops of rack units, where heat naturally rises and collects.

It’s important to note that this definition excludes the space behind racks and enclosed hot aisles because hot air should be flowing in these areas.

What Causes Hotspots?

Hotspots are caused by poor airflow. Adding more cooling equipment is a common solution for eliminating hotspots and other temperature control issues, but it rarely works. Excessive cooling combined with ineffective airflow management reduces the amount of cold air available to your equipment. As a result, localized pockets of hot air form and occupy spaces outside the hot aisle.

For example, if a data center only requires six cooling units and the operator installs nine, each unit can only use a fraction of the power it needs. The available cold air supply for the equipment decreases as a result. A poorly designed airflow management system exacerbates this issue by allowing air to flow to the wrong areas, enabling hot and cold air to mix, and sending warm air back into the rack.

These issues are most common in smaller data centers lacking proper containment aisles, especially in mixed-use buildings. Old data centers that predate containment systems are also vulnerable to hotspots.

How Do Hotspots Affect Data Centers?

Hotspots can be dangerous situations for data centers. Prolonged exposure to hotspots can:

Damage valuable equipment
Lead to system outages and equipment failures
Raise energy costs
Reduce data center reliability
Increase the risk of fires

Identifying and eliminating hotspots as soon as possible is critical for protecting your data. An ideal solution would remove existing hotspots and prevent new ones from developing.

How Can You Detect Data Center Hotspots?

Walking around your data center and feeling the air is ineffective for finding hotspots.

You may already use a handheld tool like a temperature gun or infrared device to take manual readings in specific zones. While this method is effective, it is time-consuming and inefficient for regular use.

Automated temperature monitoring solutions allow you to keep track of equipment temperatures without needing to check on them constantly. Position heat sensors at the tops of racks to catch hot air as it rises, paying particular attention to any areas where hotspots have been a problem in the past.

You can supplement your automated solutions by having staff manually check equipment at set intervals. This way, you can cover all areas in your data center and address hotspots as soon as you find one.

How to Reduce Data Center Hotspots

Managing airflow efficiency is key to reducing data center hotspots. There are many different strategies and tools you can use to solve airflow management problems — many data centers employ a combination of multiple to address every specific area.

However you choose to approach the problem, it’s critical to address your data center’s specific needs. Investing in custom design services may be advantageous for creating an optimal solution.

Install Air Containment Systems

Many data centers take a “brute force” approach to data center cooling, where they place cooling equipment against the room’s perimeter and turn them on to full blast. This solution increases cooling capacity but does not address airflow management, so only about 30% of cooled air flows to where it’s needed. As a result, data center operators often use twice as much cooling capacity as needed — and they still get hotspots.

Hot aisle containment (HAC) and cold aisle containment (CAC) systems effectively manage airflow and reduce hotspots. Here is a quick explanation of both:

HAC: The enclosed hot aisle directs the hot exhaust air from behind racks to the cooling equipment in the ceiling, which cools and returns it in the opposite direction.
CAC: This solution involves enclosing the cold aisles with transparent physical barriers to ensure cold air flows directly to server inputs.

A containment solution increases your cooling capacity and ensures airflow gets to the right places. Physical containment barriers can be placed at the ends of aisles, on the ceiling or on the wall to direct air as needed — the specific arrangement will look different in every data center.

Install Blanking Panels

If you already use a HAC or CAC containment system, you can install filler or blanking panels in racks to cover any empty spaces.

Filling gaps using blanking panels prevents hot exhaust air from flowing into those spaces and recirculating through the server rack, reducing the risk of hotspots and overheating. According to Energy Star, adding one 12-inch blanking panel to a server rack can save you 1% to 2% in energy expenditure.

Check Floor Tile Placement

Ensuring your elevated floor tiles are in the right places can help address airflow efficiency issues.

Place perforated tiles near high-density cabinets and solid tiles near low-density equipment to direct cool air to the areas that need it most.

Additionally, pay attention to how air moves underneath the tiles. You may be able to further boost cool airflow by removing obstructions in the air supply plenum, such as unstructured cabling. Obstructions often happen in areas with high-density racks. In these spaces, in-rack cooling systems are typically more efficient.

Adjust the Data Center Layout

A data center’s basic layout is often one of the biggest contributing factors to poor air circulation. Rethinking your data center’s layout and repositioning racks and equipment can significantly enhance airflow and reduce hotspots.

Another factor that causes airflow issues is rack overcrowding. Racks and computer room air conditioning (CRAC) units placed too close to each other create hotspots by allowing high-velocity air from the CRAC unit to bypass the air coming from the rack.

Additionally, ensure all high-density servers are spread evenly throughout the data center. This placement prevents hot exhaust air from building up in one spot and creating hotspots.

Aisle Containment Solutions

You can also consider using containment solutions such as aisle doors, walls, and ceiling panels to better direct the flow of air throughout the server room by creating cold and hot aisles. These containment solutions are proven to increase cooling capacity by up to 40%.

By separating the hot and cold air, you see an increased return air temperature back to the CRAC unit. This improves the overall cooling capacity and provides cooler air to the racks.

Choose Emcor Enclosures for Data Center Hotspot Mitigation

Because each data center has different requirements, a one-size-fits-all solution is rarely sufficient for hotspot mitigation. Emcor Enclosures can help you find the most effective solution for your unique data center. Whether you’re looking for aisle containment solutions, blanking panels or custom equipment, you can count on our products to improve your data center efficiency.

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