Managing Humidity to Reduce Data Center Water Consumption

Did you know that an average data center can consume around 300,000 gallons of water every day?

With data center sustainability being a top priority for many organizations around the world, it is important to remember that sustainability is not just about decreasing the use of fossil fuels and lowering carbon emissions but reducing water consumption as well.

However, according to Uptime Institute, only 43% of data centers collect data on their water usage for corporate sustainability purposes. That is in stark contrast to the 89% that collect power consumption data and 76% that calculate PUE.

Water is most commonly used for cooling the temperature in the data center, but its role in humidifying the environment may also present a good target to help reduce overall water consumption in certain facilities.

The Importance of Managing Data Center Humidity

Data center humidity must be properly managed to avoid excessively humid or dry environments which can introduce risk and inefficiencies.

Maintaining optimal humidity levels benefits data centers by:

• Minimizing energy costs and water consumption. By maintaining proper humidity levels, data centers can avoid excessive humidification which increase energy consumption and water usage. This can lead to significant cost savings and a better Water Usage Effectiveness (WUE) score.
• Enhancing cooling efficiency. Proper humidity levels help cooling systems operate more efficiently. For instance, maintaining the right humidity level allows some cooling methods to work without excessive energy use for dehumidification or humidification. This means lower operational costs and a reduced environmental footprint.
• Protecting hardware from physical damage. By keeping humidity within a certain range, data centers can avoid corrosion, electrostatic discharge, and other issues that can lead to premature hardware failure. This ensures the longevity of components like servers, switches, and storage devices, reducing the need for frequent repairs or replacements.
• Supporting airflow and temperature regulation. When humidity is controlled, airflow management techniques—like hot and cold aisle containment—can be more effective. Stable humidity levels contribute to predictable air temperature patterns, making it easier to manage cooling across different zones within the data center.

Overall, maintaining optimal humidity levels helps create a safer, more efficient, and cost-effective data center.

Optimal Humidity Levels in Data Centers

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) provides guidelines that recommend keeping data center humidity within specific ranges to protect sensitive electronic equipment and optimize efficiency.

ASHRAE's guidelines recommend maintaining a relative humidity (RH) between 40% and 70% (with caveats for certain environments), with an acceptable range between 20% and 80%. These standards are designed to minimize the risks associated with extreme humidity levels while ensuring that cooling systems operate within their most efficient range. Operating within these ranges helps data centers balance the need for cooling while avoiding excessive water use or energy consumption.

How to Monitor and Manage Humidity in the Data Center

Effective humidity monitoring is essential for ensuring optimal environmental conditions in a data center, as even small fluctuations can introduce risk. Implementing a comprehensive humidity monitoring strategy helps data center managers maintain recommended levels, prevent potential issues, and optimize cooling efficiency.

Humidity Sensors and Placement

Humidity sensors measure the amount of water vapor present in the air within the data center environment. They can detect either relative humidity (RH) or absolute humidity, with relative humidity being the more common measurement in data centers.

See some of the most popular data center humidity sensor vendors.

Humidity sensors must be strategically placed to provide a comprehensive view of the data center environment, capturing variations across different zones.

At a minimum, one humidity sensor should be deployed in a rack for every five racks, with more being used for extra coverage all the way up to sensors in each rack.

Other considerations include placing sensors in both the front and back of racks to be able to calculate Delta H, near critical equipment, and across hot and cold aisles and at different heights to detect uneven airflow and cooling imbalances.

Using DCIM Software to Simplify Data Center Humidity Monitoring

Data Center Infrastructure Management (DCIM) software can streamline humidity monitoring by providing real-time visibility into environmental conditions and alerting managers when humidity levels deviate from optimal ranges.

DCIM solutions offer several features to support effective humidity control, including:

• ASHRAE cooling chart. A leading DCIM vendor offers a patented ASHRAE psychrometric cooling chart. This helps data center managers visualize and analyze the environmental conditions of their racks against the recommended and allowable ranges. Then, corrective actions can be taken if necessary to comply industry standards.
• Thresholds and alerts. DCIM software allows data center managers to set warning and critical thresholds for humidity levels. When these thresholds are crossed, the system can trigger alerts to help proactively address issues before they potentially become serious problems.
• Floor map visual reports. DCIM software can generate floor map reports that use color-coded racks to show humidity levels in the data center. This visual representation enables data center professionals to quickly identify areas of concern and make targeted adjustments.
• Dashboard charts. DCIM software can display real-time environmental data in preconfigured dashboard charts and reports such as Latest Humidity Per Cabinet and Delta H Per Cabinet. These dashboard charts provide insights into humidity trends, helping data center managers detect patterns such as gradual increases in humidity due to seasonal changes or HVAC system wear. With this information, they can implement preventive measures before reaching critical thresholds.

By leveraging these features, DCIM software simplifies the process of monitoring and managing humidity, enabling data centers to maintain optimal conditions for equipment performance and energy efficiency.

Other Strategies to Reduce Data Center Water Consumption

Minimizing water consumption in data centers is essential for sustainable operations, cost reduction, and meeting environmental standards. Several effective strategies can potentially help achieve these goals.

Alternative Cooling Technologies

Data centers are transitioning away from water-intensive cooling systems to address sustainability goals, reduce operational costs, and improve WUE. Here is a closer look at how alternative cooling methods can contribute to reduced water consumption:

• Air-cooled vs. water-cooled systems. Air-cooled systems use fans to circulate air over the equipment, making them suitable for locations with limited water availability. They do not require water treatment or cooling towers, leading to simpler infrastructure and lower maintenance costs. However, these systems may consume more energy in warm climates and are less efficient for high-density cooling needs. In contrast, water-cooled systems rely on water for heat transfer, providing higher cooling efficiency, especially in high-density environments. While they consume less energy, they involve more complex maintenance, such as water treatment to prevent scaling, and carry risks like potential leaks.
• Free cooling. Airside free cooling uses cool outdoor air drawn directly into the data center, eliminating the need for water-intensive evaporative cooling and significantly reducing water consumption while providing energy savings. Waterside free cooling leverages cool external water sources for chilled water systems, reducing the operational demand on cooling towers and decreasing water evaporation rates. Although it is not entirely water-free, it uses less water compared to traditional methods.
• Liquid cooling technologies. Direct-to-chip liquid cooling employs non-water-based coolants or specialized fluids to transfer heat, reducing reliance on air conditioning and water-heavy evaporative cooling. Immersion cooling involves submerging components in non-conductive fluids, eliminating the need for air circulation and traditional cooling methods. Rear door heat exchangers are radiator-like doors that are mounted on the back of a rack to remove heat close to its source.

Tips to Minimize Water Usage

In addition to adopting alternative cooling technologies, other strategies can help reduce water consumption in data centers:

• Continuous humidity monitoring. Use DCIM software to track humidity levels and inform preventative adjustments to cooling systems based on real-time data.
• Hot and cold aisle containment. Separating hot and cold airflows enhances cooling efficiency, allowing higher set points. Localized humidity control within contained aisles can lower the overall water use for the facility.
• Routine maintenance for water-cooled systems. Preventive measures such as leak detection, scaling management, and optimizing cooling tower operations reduce water waste. Employing variable frequency drives for fans and pumps can enhance efficiency.
• Water reclamation and recycling. Implementing reclamation systems to collect and reuse water from cooling processes, rainwater harvesting, or municipal greywater can further reduce potable water dependence.
• Higher cooling set points. Adjusting cooling set points to be within the upper ASHRAE recommended limits reduces cooling loads and the frequency of humidification cycles, leading to water savings.

Implementing these strategies can potentially help data centers reduce water consumption and improve overall sustainability and operational efficiency.

Bringing It All Together

Effectively managing humidity in data centers not only enhances cooling efficiency but also plays a key role in reducing water consumption and supporting sustainability goals. By leveraging humidity monitoring technologies, alternative cooling methods, and strategic practices, data centers can potentially cut down on water usage without compromising performance. These efforts contribute to a more sustainable future while optimizing operational costs and maintaining equipment reliability.

Want to see how Sunbird’s world-leading DCIM software can make it easy to monitor humidity in your data center? Get your free test drive today.