Data center cooling and energy efficiency: monitoring technologies

Data center cooling is essential to ensure performance, operational continuity, and energy efficiency in digital infrastructures. Modern data centers operate 24/7 and generate large amounts of heat. For this reason, it is necessary to adopt efficient cooling systems capable of maintaining optimal temperatures, reducing energy consumption, and improving sustainability.

Data Center cooling: why is it important?

Data centers are physical facilities designed to host high-capacity servers, storage systems, uninterruptible power supplies (UPS), and all the infrastructure required to manage, process, and store large volumes of data in a centralized way.

These facilities support:

Cloud platforms
Enterprise applications
Digital services of all kinds

New-generation data centers operate continuously, 24 hours a day, 7 days a week. Inside these environments, systems such as servers and storage units generate significant amounts of heat.

The impact of GPUs on data center energy consumption

The widespread adoption of artificial intelligence applications, LLM models, and the growing demand for data are rapidly transforming the data center industry.

High-performance GPUs:

generate much higher heat densities
require more advanced cooling systems
increase overall energy demand

Data center cooling represents one of the main energy loads, accounting for approximately 40% of total consumption, second only to IT equipment. Globally, cooling systems consume around 60 million MWh per year—enough to supply electricity to hundreds of millions of households.

Why monitor data center cooling?
Monitoring data center energy efficiency enables optimization of key performance indicators:
• PUE (Power Usage Effectiveness) for electrical efficiency
• WUE (Water Usage Effectiveness) for water efficiency

Flow measurement in cooling systems
Accurate control of water-based data center cooling systems ensures hydraulic balance and uniform cooling distribution. Monitoring flow rate also allows rapid detection of leaks, blockages, or inefficiencies in components such as chillers and heat exchangers.

Data center water management: quality control
Water quality plays a crucial role in the durability and efficiency of cooling systems. Parameters such as pH, conductivity, and total dissolved solids (TDS) must be carefully controlled to prevent long-term issues. Continuous monitoring helps avoid phenomena such as corrosion and scaling, which can impair heat exchange and reduce overall system efficiency.

Data center energy efficiency monitoring
Monitoring energy consumption in data centers helps reduce operating costs and environmental impact.

Data center cooling systems

CRAH-based data center cooling

A data center cooling system based on CRAH (Computer Room Air Handler) includes several key components:

CRAH units: air conditioning units designed to maintain controlled temperature and humidity within server rooms
Air distribution system: via raised floors or ductwork to ensure proper air circulation
Cooling coils: use chilled water, often glycol-based, to transfer heat from indoor air to the cooling fluid
High-efficiency fans: ensure continuous air movement between CRAH units and IT equipment
Cooling plant: includes external chillers, cooling towers, or free-cooling systems, forming the core of the cooling chain

The process involves drawing in hot air generated by servers, cooling it through the CRAH unit coils, and recirculating cooled air back into the room, ensuring a continuous and optimized air conditioning cycle.

Sistema di raffreddamento datacenter con crah con esempio di installazione della thermag valve

Sistema di raffreddamento a immersione monofase per data center con esempio di installazione della thermag valve

Single-phase immersion cooling for data centers

Liquid immersion cooling using dielectric fluids is one of the most advanced solutions for thermal dissipation in high-density data centers. Single-phase immersion cooling technology offers significant advantages in terms of energy efficiency, reliability, and increased computing density, contributing to reduced energy consumption and improved infrastructure sustainability.

In single-phase immersion cooling systems, servers are fully immersed in a dielectric fluid that does not conduct electricity. This fluid absorbs heat generated by electronic components and dissipates it through a CDU (Cooling Distribution Unit).

Inside the CDU, a heat exchanger transfers thermal energy to chilled water, which is then cooled by refrigeration systems such as chillers or dry coolers.

ISOIL Industria technologies for data center monitoring

ISOIL Industria offers a wide range of measurement instruments that fully meet the needs of data center operators.

MV800 + MV311

To maximize the performance of liquid cooling systems in data centers, accurate thermal energy measurement is essential. Instruments such as the MV800 and MV311 combination ensure precise and reliable measurements even in confined spaces and high-humidity environments.

These devices are suitable for:

Measurements on liquids with minimum conductivity of 20 µS/cm
Accuracy of ±0.5%
Compatibility with ISOMAG sensors up to DN400
Compliance with MID MI001 and MI004 certifications

The MV800 + MV311 combination is widely used in data centers due to several advantages:

ISOMAG sensors operate without the need for straight pipe runs
The MV311 can be powered via PoE and supply power to the MV800, reducing power supply points
High processing speed enables real-time adjustment of power, flow, and temperature parameters
Accurate calculation of thermal energy and power even with glycol-based fluids, by selecting fluid type and concentration to apply the correct specific heat

CS611 Thermag Valve

In data center cooling systems, the CS611—an intelligent valve with integrated electromagnetic thermal energy meter—performs the following functions:

Energy measurement: enables accurate measurement of transferred thermal energy, supporting performance analysis and operational efficiency control
Automatic hydronic balancing: ensures uniform distribution of thermal energy to each CDU, regardless of pressure variations or demand
Pressure-independent control: regulates flow rate even under pressure fluctuations, ensuring operational stability
Delta T management: maintains a constant temperature difference, preventing “Low Delta T Syndrome” and preserving system efficiency
Dielectric fluid temperature control: maintains stable bath temperature, preventing anomalies and respecting flow rate and delta T alarm thresholds

Key advantages:

Maximum energy efficiency: optimizes heat exchange and ensures ideal conditions for CPUs and GPUs, reducing energy waste
Improved PUE: enhanced thermal efficiency directly contributes to lower PUE values
Reduced operating costs: simplifies system architecture and reduces installation costs by integrating multiple functions into a single device, easing BMS integration
Lower maintenance costs: active control of operating conditions reduces wear on components (pumps, heat exchangers, compressors), extending system lifespan

FAQ

Air vs. liquid data center cooling: what are the differences?

Air cooling (via CRAC/CRAH systems) is the traditional standard, ideal for medium-low power density infrastructures (up to 10–15 kW per rack). Liquid cooling, on the other hand, removes heat directly at the source (e.g. Direct-to-Chip or immersion cooling) and is essential for modern data centers hosting AI and high-performance computing (HPC) applications, where rack densities easily exceed 30–50 kW, offering significantly higher heat dissipation capacity.

Why is flow measurement important in liquid cooling systems?

In liquid cooling systems, accurately quantifying coolant flow is essential to ensure uniform heat distribution and prevent localized overheating (hot spots on servers).

How does water quality affect cooling efficiency?

The use of water in closed loops or cooling towers requires strict control. Poor water quality can lead to corrosion, biological growth, and scaling, which act as thermal insulators on heat exchangers. Real-time monitoring of parameters such as pH, conductivity, and TDS is essential to maintain optimal heat transfer performance and avoid downtime.

What are the key KPIs for measuring cooling efficiency?

The most important global indicators are PUE (Power Usage Effectiveness) and WUE (Water Usage Effectiveness). At the operational level, it is essential to monitor delta T (temperature difference between supply and return), flow rate, and the specific energy consumption of chillers and pumps.

How can efficient cooling reduce OPEX?

Cooling systems can account for up to 40% of total energy consumption in a data center, making efficiency improvements a key lever for reducing operating expenses.

What are the best strategies for sustainable data center cooling?

To reduce carbon footprint and improve sustainability, most data centers are adopting advanced flow measurement and thermal energy metering solutions, along with strategies such as transitioning from air to liquid cooling for high-density loads, using environmentally friendly dielectric fluids, and recovering waste heat for district heating networks.

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