Precision control unit (PCU) specifications vary widely by application and manufacturer, but typically include a cooling capacity range (e.g., 5–90 kW), operating voltage (e.g., 380–400 VAC, 3-phase), temperature control (e.g., 23± 3 °C or ± 0.5°C) and humidity control

(e.g. 45±15% RH or ± 2% RH). Other common specifications involve the type of compressor (scroll or inverter), refrigerant (like R410A or R407C), and airflow configuration (upflow or downflow). 

Cooling capacity and efficiency 

• Cooling Capacity: Ranges from small units (around 5.9 kW) to large systems exceeding 100 kW, with typical models in the 15–90 kW range.
• Sensible Cooling: A key metric for data centers, representing the capacity to handle sensible heat load. For example, a 45.3 kW total capacity unit might have a 42.5 kW sensible capacity.
• Energy Efficiency Ratio (EER) or Annual Energy Efficiency Ratio (AEER): Indicates efficiency; a higher AEER signifies greater efficiency (e.g., 3.6 W/W). 

Environmental controls 

• Temperature Control: Typically maintains a precise temperature, often with an accuracy of  ±0.5°C. The setpoint is usually between 17−28°C for data centers.
• Humidity Control: Precise units can maintain relative humidity within a tight range, such as ±2% or ±5% RH, often set between 40–60% RH. 

Power and electrical specifications 

• Operating Voltage: Commonly operate on 380/400 VAC 3-phase power, but some models may support 230/220 VAC or 1-phase power.
• Power Consumption: Varies with cooling capacity and other features.
• Power Factor: Some units specify a power factor requirement for efficient power usage. 

Component and system specifications 

• Compressors: Scroll compressors are common, with some advanced systems using more efficient inverter compressors.
• Refrigerant: Examples include R410A or R407C, depending on the unit’s age and design.
• Airflow: Units can be configured for upflow or downflow air delivery.
• Control System: Advanced control systems manage temperature, humidity, fan speed, and other parameters, often with remote connectivity for monitoring and alerts.