Maintaining proper cooling in a data center is both a science and an art. One often overlooked yet essential tool in this realm is the blanking panel. Blanking panels are flat filler plates (typically metal or plastic) used to cover empty rack units in server cabinets. While simple in concept, they play a critical role in airflow management, preventing hot and cold air from mixing and thereby keeping servers within safe temperature ranges. In fact, industry experts and organizations like ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) consider the use of blanking panels a best practice for any efficient data center cooling strategy (A Quick Overview of the Importance of Blanking Panels – 42U) (Blanking Panels: Why Your Server Racks Need Them). This post will explore why blanking panels are so important, how they contribute to optimized airflow and energy efficiency, and how they help data centers comply with industry standards. Along the way, we’ll also highlight how solutions such as Eziblank’s blanking panels embody these principles, offering an effective means to achieve better cooling performance without an overly promotional tone.
What Are Blanking Panels and Why Do They Matter?
In a typical server rack, any unused rack unit (U) space becomes an opportunity for airflow to behave unpredictably. Blanking panels (also called filler panels) fill those gaps, ensuring that airflow follows the intended path. Without blanking panels, hot exhaust air from servers can loop around and recirculate into the front of the rack, where servers draw in cooling air. This causes intake temperatures to rise and forces server fans and cooling systems to work harder. The result is a less efficient cooling cycle and potential hot spots that threaten equipment health. According to IBM’s data center guidelines, all unoccupied rack space should be filled with blanking panels to eliminate hot air recirculation (General guidelines for data centers). By simply covering those empty slots, blanking panels create a barrier that separates the cold intake air from the hot exhaust air, preserving the intended hot aisle/cold aisle separation inside the rack.
A data center technician installs blanking panels in a server rack. By covering empty rack units, the panels prevent hot exhaust air from recirculating to the front of the rack, thus maintaining proper cold aisle (front) and hot aisle (rear) separation.
The concept is straightforward: blanking panels force cold air to take the correct route through the servers, rather than spilling through open gaps. In doing so, they channel cooling where it’s needed (through equipment) and block it from bypassing to unused spaces. ASHRAE’s Technical Committee 9.9 and most major server manufacturers have long recognized this benefit, recommending that all unused rack openings have blanking panels installed to maximize the effectiveness of hot/cold aisle airflow management (A Quick Overview of the Importance of Blanking Panels – 42U). In essence, blanking panels are a low-tech solution that addresses a high-tech problem – they physically enforce the separation of air streams that your data center’s design is trying to achieve. This makes them fundamental components of any well-designed cooling layout, including advanced setups like cold aisle or hot aisle containment.
Optimizing Airflow and Preventing Hot Air Recirculation
One of the primary advantages of blanking panels is optimized airflow. In a properly arranged data center (often a cold-aisle/hot-aisle layout), server racks are placed so that fronts of servers face each other (cold aisles) and backs face each other (hot aisles). Cool air is delivered to the front of racks, drawn through the servers, and hot air is expelled out the back into the hot aisle. However, if there are open slots in the racks, that careful airflow pattern breaks down: hot air can slip around to the front through those gaps, and cold air can leak through without cooling anything. Installing blanking panels across empty rack units and sealing other gaps is therefore essential to maintain proper aisle separation. This prevents the intermixing of cold supply air with hot exhaust air, keeping the cold aisle truly cold and the hot aisle contained.
The impact of this containment is significant. By preventing hot air from being drawn back into servers, blanking panels eliminate many cooling issues. Equipment intake temperatures stay lower and more uniform from the bottom to the top of the rack. This not only avoids localized hot spots but also means each server in the rack gets the coolest possible air available. The U.S. Energy Star program notes that simple airflow management measures like blanking panels and grommets “keep cold air from mixing with hot exhaust air”, directly improving cooling effectiveness. In one example, a large data center was able to save around $360,000 annually just by implementing inexpensive airflow management improvements, including using blanking panels to seal openings (16 More Ways to Cut Energy Waste in the Data Center | ENERGY STAR). Clearly, sealing those small gaps leads to big benefits.
From a reliability standpoint, better airflow management means less stress on hardware. Servers won’t rev their internal fans as much to compensate for rising inlet temperatures, which reduces wear and tear. It also means fewer chances of components overheating due to unintended recirculation. In short, blanking panels help create a controlled airflow environment, so cooling resources go where they should and your equipment stays within safe operating temperatures.
Energy Efficiency Benefits of Proper Blanking Panel Use
Beyond just cooling performance, blanking panels contribute heavily to energy efficiency in the data center. Cooling systems often account for a huge portion of a data center’s energy consumption. When airflow is unmanaged (i.e., hot and cold air freely mix), cooling units must work overtime to keep temperatures down. By contrast, when blanking panels are used to optimize airflow, the cooling system can run more efficiently because cold air isn’t wasted and hot air isn’t contaminating the intake. This can translate into noticeable cost savings on power bills and a lower PUE (Power Usage Effectiveness) for the facility.
Several industry studies and real-world deployments have demonstrated the energy-saving impact of blanking panels. For example, Upsite Technologies (an airflow management firm) commissioned a CFD analysis that found properly sealed blanking panels reduced average server inlet temperatures by about 7°F (3.9°C), compared to racks with unsealed gaps. With intake air that much cooler, data center operators can raise their CRAC unit set points by a similar 7°F without any negative impact on equipment. Raising the thermostat in a server room yields immediate energy savings – in this case, the analysis estimated roughly 28% cooling energy savings when increasing supply air temperature from 65°F to 72°F. This is a dramatic example, but it underscores a key point: when you eliminate hot air recirculation with blanking panels, you gain flexibility to raise temperatures and cut cooling costs.
Even modest improvements in airflow can add up. According to Data Center Knowledge, adding just a single 1-foot blanking panel in a rack can yield about 1–2% energy savings for cooling (Energy Efficiency Guide: Assessment – Data Center Knowledge). While that figure might vary, it illustrates that every rack unit sealed is a little less work for your AC. Over dozens of racks, those gains become substantial. In many cases, the investment in blanking panels pays for itself within months due to the energy reduction (Blanking Panels: How Sealing Small Gaps Can Lead to Big Savings – Upsite Technologies – Data Center Cooling Optimization). It’s no surprise, then, that blanking panels are frequently touted as a quick win for data center efficiency – they are low cost, easy to implement, and immediately start plugging energy-wasting leaks in your cooling system.
Furthermore, efficient airflow management aligns with sustainability goals. By reducing the power needed for cooling, blanking panels indirectly cut the carbon footprint of the data center. In an era where data center energy use is scrutinized, something as simple as installing filler panels can contribute to greener operations. It’s a classic example of how good facility management practices also drive energy conservation.
Industry Best Practices and ASHRAE Guidelines Compliance
Leading standards organizations and data center best practice guides emphasize the importance of blanking panels as part of a holistic cooling strategy. ASHRAE, which publishes widely respected thermal guidelines for data centers, has long recommended strategies to prevent air recirculation and maintain proper equipment inlet temperatures. In its guidance on hot aisle/cold aisle arrangements (first introduced as a standard practice in 2004), ASHRAE’s Technical Committee 9.9 explicitly recommends using blanking (filler) panels to cover any unused rack openings (Tips to build a data center airflow management strategy | TechTarget). This recommendation is echoed by essentially all major server and storage manufacturers as well, who often ship or suggest filler panels for their rack installations. Simply put, blanking panels are now considered a standard requirement for any data center serious about following industry best practices.
ASHRAE’s thermal guidelines specify recommended temperature ranges for IT equipment intake (generally 18°C to 27°C for class A1/A2 equipment, roughly 64–81°F). Using blanking panels helps operators stay within these recommended ranges by preventing hotspots and uneven cooling. By keeping inlet temperatures consistent and within ASHRAE’s recommended envelope, you ensure compliance with the environmental conditions that manufacturers and insurance policies often expect. Blanking panels thus contribute to meeting ASHRAE Standard 90.4 (Energy Standard for Data Centers) indirectly, by enabling more efficient cooling performance and energy use in line with its objectives for energy-efficient operation.
It’s worth noting that modern data centers often employ aisle containment systems (either cold-aisle or hot-aisle containment) for even greater efficiency. Blanking panels are a fundamental element of those containment strategies. As one containment solutions provider put it, leaving open rack space without blanking panels will undermine containment effectiveness, because air will leak and mix where it shouldn’t (Cold Aisle Containment Systems (CAC) – Cool Shield). Thus, even with advanced cooling designs, the humble blanking panel remains a cornerstone of airflow management discipline.
Industry groups and experts routinely list blanking panels in checklists of cooling best practices. For example, a CoreSite data center best practices article advises that “blanking panels should be installed across empty rack units” to improve cooling efficiency, noting that these panels prevent hot air from being drawn into server intakes (6 Best Practices for Optimizing Data Center Cooling). Likewise, the Uptime Institute and other data center authorities include sealing rack openings as a critical step in any airflow optimization plan. The consensus is clear: to meet industry standards and guidelines (including those from ASHRAE), using blanking panels is no longer optional – it’s essential.
Implementing Blanking Panels: Tips for Best Results
Installing blanking panels in your data center is relatively straightforward, but a few best practices will ensure you get the maximum benefit:
- Cover Every Unused Rack Unit: It only takes a small gap to cause air leakage. Make sure all empty rack slots – no matter how small – are filled with blanking panels. Partial measures leave cooling efficiency on the table. Use appropriately sized panels (1U, 2U, 4U, or larger multi-U panels) to cover openings completely.
- Use Tool-less Panels for Flexibility: In a dynamic data center, servers and equipment may move or change frequently. Consider using tool-less blanking panels (snap-in designs) which can be installed or removed in seconds. This encourages technicians to replace panels immediately after moving gear, maintaining airflow integrity. (Many modern blanking panels, including Eziblank’s designs, feature quick snap-in installation for this reason.)
- Seal Other Gaps and Openings: Blanking panels address the spaces within rack unit bays, but don’t forget other leak points. Use brush strips or grommets to seal cable cutouts and gaps around rack edges, and ensure floor tiles or containment doors don’t have unsealed openings. The goal is a tight separation between cold and hot areas on all fronts.
- Monitor Rack Inlet Temperatures: After installing blanking panels, monitor the intake temperatures at different heights of your racks. You should notice a more uniform temperature profile. Monitoring helps verify that the blanking strategy is effective and that you remain within ASHRAE-recommended temperature ranges. Some blanking panels even come with built-in temperature strips or sensors to aid in this monitoring.
- Combine with Aisle Containment if Possible: For maximum efficiency, use blanking panels in conjunction with aisle containment or at least a hot aisle/cold aisle layout. Blanking panels ensure the rack-level airflow is controlled, and containment (or even simple curtains or partitions) can further prevent mixing at the room level. Together, these measures can significantly lower overall cooling energy needs.
By following these practices, data center operators can achieve what ASHRAE and other experts call “good airflow management” – meaning all cooling air reaches the IT equipment and all hot air is removed without contaminating the next cycle. It’s a recipe for lower energy bills and higher reliability.
Enhancing Efficiency with Blanking Panels (and Eziblank’s Expertise)
Blanking panels may be unassuming pieces of plastic or metal, but their impact on data center performance is profound. From optimized airflow and elimination of hot spots, to improved energy efficiency and alignment with ASHRAE’s best practice guidelines, these filler panels are a small investment that pays huge dividends. They help create the stable thermal environment that sensitive servers require, and they enable cooling systems to run at peak efficiency rather than in overdrive. In a world where data centers are expected to be both high-performing and cost-effective, neglecting something as fundamental as blanking out empty rack space is no longer an option.
Importantly, leveraging blanking panels doesn’t mean re-inventing the wheel – it means adopting industry-approved solutions. Eziblank, an Australian-based innovator in data center airflow management, has established itself as an authority in this domain. The company’s blanking panel solutions are designed around these very principles: easy installation, effective sealing of server cabinet openings, and durable construction to support long-term airflow optimization. By incorporating Eziblank’s panels (or similar high-quality products) into your racks, you’re essentially applying the combined wisdom of ASHRAE and decades of data center operations experience to your facility. The result is a data center that runs cooler and more efficiently – without costly infrastructure overhauls.
In summary, blanking panels are a simple yet powerful tool for any data center professional aiming to maximize cooling efficiency and ensure a safe operating environment for equipment. They embody industry best practices and are backed by standards organizations that recognize their value in preventing air recirculation and wasted energy. By implementing blanking panels according to best practices, and by turning to expert solution providers like Eziblank for guidance, you can achieve optimized airflow management with minimal effort. Small blanking panels make a big difference – keeping your data center cool, energy-efficient, and compliant with the highest standards of performance. Embracing this often overlooked aspect of data center design will pay off in reliability, savings, and peace of mind, knowing that your facility is running as smart and efficiently as possible.
