It's an interesting time in data management.
Not only are we now seeing an exponential increase in the volume of data processed and stored every second of every day, but also the types of data being collected and analyzed are becoming more complex and diverse.
Twenty years ago, no one would have ever expected things such as digital currencies or cloud computing to take off the way they have.
While the digital world and its data continue to grow, its roots are still firmly planted in reality. More specifically, data management and storage very much have an actual address in the real world. Like new scores of data each day that are created, data centers are not only becoming more common but also more complex.
Keeping the data housed in data centers safe and accessible isn't always about having the best cybersecurity. With a real-world presence comes the same issues in indoor climate control that all buildings face.
In this article, we'll dig into one of the most important environmental elements to keep in check in a data center: humidity control.
Humidity in Data Centers
If there’s a natural enemy of sorts for electronics, there’s no question it’s moisture. This is especially true in data centers.
The bottom line is that humidity levels that are too high or too low can wreak havoc on sensitive equipment, leading to unexpected downtime, costly repairs, and even data loss.
What's more, there's very little inside a data center that isn't vulnerable to moisture issues – servers, networking hardware, storage devices, and plenty more. Even a little moisture – usually in the form of humidity – can cause big problems for everything comprising a data center.
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Equipment Performance Data center hardware, from servers to networking devices, is sensitive to moisture. High humidity levels can lead to condensation forming on critical components, causing malfunctions and even permanent damage. By adhering to data center temperature and humidity standards, operators can ensure that equipment remains functional and free from moisture-related failures. |
Risk of Static Electricity When humidity levels drop too low, the risk of static electricity increases. Static discharge can wreak havoc on sensitive electronics, leading to costly damage. The effect of low humidity in data centers is often unseen until it's too late, with electrostatic discharge silently destroying essential components. Following ASHRAE data center humidity guidelines helps keep the environment safe from these risks, ensuring consistent performance. |
Corrosion and Condensation Excess moisture can lead to corrosion, particularly on metal components within servers and other equipment. Additionally, high humidity in data centers increases the risk of condensation, which can result in short circuits and other equipment failures. An effective data center humidity control system is key to preventing these issues, helping to protect valuable assets from both corrosion and condensation damage. |
Suffice it to say, humidity control is one of the most important aspects of maintaining a stable environment inside a data center.
When discussing humidity in data centers, it's important to understand that there are multiple ways to measure and describe moisture in the air. Each method offers a different perspective on how moisture interacts with the environment, and understanding these distinctions can help ensure proper data center humidity control.
Relative Humidity (RH) is the most commonly discussed measure of humidity, representing the percentage of moisture in the air relative to the maximum amount it can hold at a given temperature. While it's a useful benchmark, RH is just a number — it doesn't tell the whole story. It’s highly dependent on temperature, so it can fluctuate even when the actual amount of moisture in the air (mass of water vapor) remains unchanged. For data centers, relative humidity is crucial to monitor, but it shouldn't be the only metric relied upon.
Dew Point (DP) provides a more concrete measurement of moisture by indicating the temperature at which air becomes saturated, leading to condensation. For data centers, knowing the dew point is critical for avoiding condensation on servers and sensitive equipment. High data center air pressure can exacerbate this risk, and tracking the dew point can help ensure that conditions remain safe. Dew point is especially useful for data center temperature and humidity monitoring systems, as it offers a clearer picture of the true moisture content in the air.
Wet Bulb Temperature takes into account both heat and humidity to determine the lowest temperature that air can reach through evaporative cooling. Wet bulb temperature plays a role in understanding exfiltration — the movement of air and moisture out of the data center. Like the dew point, wet bulb is a more practical measure when discussing the risk of condensation and its potential impact on equipment.
In certain situations, particularly when considering the mass of water vapor in the air, it's also useful to account for water vapor pressure. This can offer additional insights into how much moisture is present, independent of temperature.
By employing a combination of these measurements, data center operators can ensure a more comprehensive approach to humidity in data center best practices, protecting both equipment and uptime.
Sources of Moisture in a Data CenterMoisture in a data center can originate from several sources, all of which need to be closely monitored to prevent equipment damage. One common source is the outside air, which can bring in humidity if not properly conditioned by the HVAC system. Additionally, human activity — such as the presence of personnel — can introduce moisture into the environment. Another major & newer contributor to data center humidity levels is a type of cooling system many are turning to keep temperatures in check. Liquid cooling systems, which, while highly efficient at dissipating heat, can also increase the risk of condensation if leaks occur or humidity is not controlled. |
Data Center Humidity Control Strategies Via Sensor Tech
When it comes to how to control humidity in a data center, there's no strategy that doesn’t involve sensor technology. Sensors are the backbone of controlling humidity in data center best practices, allowing real-time monitoring and adjustments to maintain an ideal environment.
At a macro level, data center temperature and humidity monitoring system is HVAC with humidity and temperature sensors carefully integrated throughout.
HVAC Humidity Sensors
In HVAC design, there are two primary types of humidity sensors commonly used to achieve this control:
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Capacitive Sensors work by detecting changes in electrical capacitance as humidity levels fluctuate. These sensors contain a thin layer of polymer or metal oxide that absorbs water vapor. As the moisture content changes, so does the capacitance, providing an accurate measurement of the data center's relative humidity.
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Resistive Sensors measure humidity by tracking changes in the electrical resistance of a material in response to moisture in the air. As the humidity rises, the material’s resistance decreases, allowing the sensor to provide a reading.
So which type of humidity sensor is best for data center applications?
Capacitive sensors, and for several reasons. While both capacitive and resistive sensors are effective in measuring moisture levels, capacitive sensors offer distinct advantages that make them better suited for the highly sensitive and demanding environment of a data center.
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Greater Accuracy and Stability Capacitive sensors are known for their precision, especially when it comes to tracking data center relative humidity over time. They maintain a high level of accuracy even in fluctuating conditions, making them ideal for environments where small changes in humidity could lead to major equipment issues. This long-term stability is crucial in maintaining the delicate balance of data center temperature and humidity. |
Faster Response Time One of the critical advantages of capacitive sensors is their ability to respond quickly to changes in humidity. In a data center, where rapid adjustments may be needed to prevent condensation or mitigate static electricity, the faster response time of capacitive sensors provides a significant operational advantage. This allows HVAC systems to make real-time corrections, keeping humidity levels within the optimal range. |
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Long-Term Durability Capacitive sensors are typically more durable than resistive sensors, especially in environments like data centers that require continuous, 24/7 monitoring. They are less prone to drift or degradation over time, which means they provide consistent readings and require less frequent calibration, contributing to lower maintenance costs. |
Better Performance in Extreme Conditions Data centers often face varying levels of temperature and humidity, and capacitive sensors perform better in these extreme conditions. Resistive sensors can be less reliable when exposed to high humidity or rapid environmental changes, while capacitive sensors maintain their performance, making them more dependable for long-term use. |
HVAC Temperature Sensors
Put simply, there's no way to design an HVAC system that does its primary function without temperature sensors – unless you're looking for a glorified fan.
When it comes to controlling humidity, HVAC temperature sensors work hand in hand with humidity sensors to provide real-time feedback on changes within the data center environment. It comes down to basic science: Hotter air can hold more moisture than colder air, which means temperature fluctuations can have a direct impact on relative humidity levels.
What's more, temperature control matters in its own right. Heat is a significant contributor to equipment failure, and temperature sensors provide an added layer of protection by allowing data center operators to adjust cooling systems before equipment overheats.
Air Flow & Pressure: Data Center Humidity Control in Motion
Effective data center humidity control isn't just about keeping airborne water vapor numbers and temperatures within an optimal range. It’s also closely tied to airflow and pressure control, which can directly affect humidity levels.
How?
Another basic science lesson of sorts.
By maintaining the right pressure levels, data centers can optimize airflow, enhance cooling, and keep humidity levels within the data center's ideal temperature and humidity range.
A pressurized environment helps ensure humid air is vented properly and dry air circulates effectively. Without the right pressure balance, moist air can stagnate, leading to condensation and other humidity-related issues. By controlling pressure, the HVAC system can maintain consistent air movement, ensuring that moisture is removed before it becomes a problem. This balance is critical for maintaining a stable environment and protecting sensitive electronics.
Another key function of pressure control in data centers is to prevent air infiltration from external sources. Think of it as similar to keeping a clean room clean. If the internal pressure is too low, outside air — often containing contaminants or moisture — can infiltrate the data center. This unconditioned air can introduce dirt, dust, and excess humidity into the facility, which not only disrupts humidity control but also increases the risk of contamination to sensitive equipment. By maintaining positive pressure, a data center can create a barrier that prevents external air from entering, keeping contaminants out and ensuring the indoor environment remains clean and stable.
Fan Arrays & Filter Differential Pressure: Maintaining Balance for Movement
While pressure control is a critical aspect of data center humidity control, it's not something that can be set and forgotten. To keep things running smoothly, HVAC systems need to continually monitor and adjust the balance of pressure within the facility. That's where fan arrays come into play. Using multiple fans working together, the arrays provide consistent airflow throughout the data center.
But managing pressure isn't just about maintaining optimal levels — it's also about keeping a balance between different areas of the data center. For example, maintaining proper differential pressure between hot and cold aisles is essential for efficient cooling and preventing air contamination. By tracking filter differential pressure, which measures resistance against airflow due to clogged filters, HVAC systems can maintain a consistent balance of pressure within the data center. This helps ensure that air flows in the right direction and keeps contaminants at bay.
The Pressure Sensors That Make Data Humidity Control PossibleSeveral types of pressure sensors are used in data centers, each designed to handle different aspects of pressure monitoring:
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Data Center Humidity Control: Stopping a Problem Before it Starts
No matter the reason why, the last things anyone wants to deal with in a data center are equipment failures and downtime. Both of those things cost time and money.
By leveraging advanced sensor technology and maintaining proper pressure and airflow, data centers can keep humidity levels in check and protect sensitive equipment. Proactive monitoring and maintaining the right balance of temperature and humidity ensures a stable environment, stopping problems before they start.
