What Is The Difference between Precision Air Conditioning And In-row Air Conditioning in Server Rooms?

What is the difference between precision air conditioning and row-based air conditioning for data centers?

Design and Installation Location

Precision Air Conditioning:

This is a “centralized cooling” system typically installed in corners, on walls, or in ceiling areas of the data center, rather than directly embedded within server cabinet rows. It has a relatively large footprint and requires sufficient installation space, often relying on the data center's overall air duct system (e.g., raised floor supply air, ceiling return air) to achieve air circulation.

Row-based air conditioning:

This is a “distributed close-range cooling” device specifically designed for server cabinet clusters. It is directly installed between cabinet rows (e.g., between two rows of cabinets) or at the end of cabinets. It has a compact structure, typically occupying only half a cabinet's space, and can be positioned close to heat sources, reducing the distance air must travel for cooling.

Cooling Methods and Efficiency

Data Center Precision Air Conditioning:

Operates in “long-distance air supply” mode, centrally processing data center air and distributing cool air from the air conditioning unit throughout the entire data center space, then returning hot air via the return air system for processing. Since cold air needs to spread to every corner of the data center, there may be cold air loss during the airflow process, and “hot and cold air mixing” may occur, leading to “hot spots” in localized areas (such as inside cabinets), resulting in relatively low energy efficiency (especially in high-density cabinet environments).

Row-based air conditioning:

Adopts a “close-range precise cooling” mode, directly extracting hot air from the hot aisle where cabinets are located, processing it, and then delivering cold air directly into the cold aisle of the cabinets. This “hot/cold aisle isolation” design maximizes the reduction of cold air loss, lowers air delivery energy consumption, and is particularly suitable for high-power-density cabinets (such as blade server clusters), significantly improving cooling efficiency and reducing data center PUE (Power Usage Effectiveness) of data centers.

Application Scenarios

Precision Air Conditioning for Data Centers:

Suitable for data centers with medium to low power density (e.g., single cabinet power ≤5kW) or scenarios where cabinets are sparsely arranged and equipment heat distribution is uniform. Examples include traditional small to medium-sized data centers, data centers with fewer servers, and environments with low requirements for cooling flexibility.

Row-based air conditioning:

Suitable for high-power-density data centers (e.g., single-cabinet power ≥8 kW) or scenarios with densely arranged cabinets and concentrated heat generation. Examples include high-density cabinet zones in large data centers, cloud computing data centers, and edge data centers, where it can address localized high-heat issues and prevent equipment downtime caused by hotspots.

Control Precision and Scalability

Data Center Precision Air Conditioning:

Primarily controls the average temperature and humidity of the entire data center, with precision typically around ±1°C (temperature) and ±5% (humidity). Its capacity is fixed, so if the data center's thermal load increases, the entire system must be replaced or additional units added, resulting in poor scalability.

Row-based air conditioning:

Enables precise temperature control for individual cabinet rows or localized areas, with temperature control accuracy as high as ±0.5°C. It can respond in real-time to changes in cabinet heat load (e.g., by monitoring cold aisle temperatures via sensors and dynamically adjusting airflow and cooling capacity). Additionally, row-based air conditioning adopts a modular design, allowing units to be flexibly added based on cabinet quantity or increased heat load, offering superior scalability.