Environmental Monitoring: Sensors For Temperature And Humidity Control

Data centers house expensive computing equipment and infrastructure. It therefore makes economic sense to ensure that this equipment and infrastructure is properly maintained. Optimizing climate control is a key part of this. Here is a quick guide to what you need to know.

The importance of temperature and humidity control

All electronic equipment has an optimal operating environment. While the exact details may vary, electronic equipment tends to function best in a cool, dry environment.

The challenge for data centers is that all electronic equipment generates heat in use. Advances in energy efficiency have reduced the heat they produce. Unfortunately, the benefit of this has been counterbalanced, if not outweighed, by the fact that data centers are packing more powerful equipment more densely.

Moreover, humidity is also an issue in data centers. Equipment typically works best when the air is dry but not excessively dry. Humidity levels are influenced by many factors and can vary greatly over a single day and even more so over longer periods. This means that data centers generally benefit from being able to adjust humidity in either direction.

How sensors monitor and maintain optimal conditions

There are five main ways sensors monitor and maintain optimal conditions. Here is an overview of them.

Real-time data collection

Temperature and humidity sensors continuously monitor environmental conditions within data centers. These sensors are strategically placed throughout the facility to capture comprehensive data. They collect readings at regular intervals, typically in seconds or minutes, ensuring that operators have up-to-date information about the thermal and moisture conditions within the facility.

Data analysis and threshold setting

Once sensor data is collected, it undergoes analysis to identify trends, patterns, and anomalies. Data analysis algorithms compare current readings to predefined thresholds for temperature and humidity levels. If sensor readings exceed or fall below these thresholds, it triggers alerts to notify data center operators of potential issues.

Dynamic control of HVAC systems

Environmental monitoring systems integrate with Heating, Ventilation, and Air Conditioning (HVAC) systems to maintain optimal conditions. When sensors detect deviations from set thresholds, they send signals to HVAC systems to adjust cooling, heating, and humidity control mechanisms accordingly.

For example, if temperatures rise above acceptable levels, the HVAC system can increase airflow or activate additional cooling units to bring temperatures back within the desired range.

Redundancy and failover systems

To enhance reliability, data centers often incorporate redundancy and failover systems into their environmental monitoring and control infrastructure. Redundant sensors ensure continuous monitoring by providing backup measurements in case of sensor failures or malfunctions.

Similarly, failover mechanisms within HVAC systems ensure that backup cooling and ventilation mechanisms are activated promptly in the event of primary system failures.

Continuous monitoring and optimization

Environmental monitoring in data centers is an ongoing process that involves continuous monitoring, analysis, and optimization. Data center operators regularly review sensor data and system performance to identify opportunities for improvement.

By fine-tuning environmental control settings and optimizing HVAC system operations based on real-time sensor data, data centers can achieve greater energy efficiency, cost savings, and overall operational resilience.

Types of temperature sensors used in data centers

Here is an overview of the three main types of temperature sensors used in data centers.

Thermocouples: Thermocouples consist of two dissimilar metals that generate a voltage proportional to the temperature difference between their junctions. They offer wide temperature ranges and fast response times but may have lower accuracy compared to other types.

Resistance temperature detectors (RTDs): RTDs use a fine wire made of a pure metal, such as platinum, whose electrical resistance changes predictably with temperature. They provide high accuracy and stability over a wide temperature range, suitable for precise monitoring in data center environments.

Thermistors: Thermistors are semiconductor devices with a resistance that changes significantly with temperature. They offer high sensitivity and fast response times but may have a limited temperature range compared to other sensors.

Types of humidity sensors used in data centers

Here is an overview of the three main types of humidity sensors used in data centers.

Capacitive humidity sensors: Capacitive humidity sensors measure changes in capacitance due to the absorption of water vapor by a dielectric material. They provide accurate and reliable measurements over a wide humidity range and are commonly used in data centers for monitoring relative humidity levels.

Resistive humidity sensors: Resistive humidity sensors use a humidity-sensitive polymer or metal oxide film whose electrical resistance changes with humidity. They offer cost-effective solutions for measuring relative humidity but may have limitations in accuracy and long-term stability compared to capacitive sensors.

Thermal conductivity humidity sensors: Thermal conductivity humidity sensors measure the thermal conductivity of air, which varies with humidity levels. They provide accurate measurements over a wide humidity range and are suitable for applications where high accuracy and stability are required, such as in data center environments.