How Does a PAC Unit Work
The foundational working principle of a Precision Air Conditioner isn’t much different from that of a “normal” AC. It’s the way it maintains strict temperature and humidity control and offers superior redundancy that makes it different and worth studying.
A. The Fundamental Working Principle of a Precision AC
The basics remain the same. The PAC draws in warm air from the room. This air typically contains both sensible heat (the heat that increases air temperature) and latent heat (moisture content in the air).
Warm Air Is Drawn Across The Evaporator
The warm air is drawn across the evaporator coil. This coil contains low-pressure liquid refrigerant. As the air passes over the coil, sensible heat (the heat that raises air temperature) is removed, cooling the air. If the air is humid, latent heat (from moisture) is also removed, causing water vapor to condense on the coil.
Refrigerant Turns To Low Pressure Gas Upon Heat Absorption
As the coil absorbs the heat from the air, it turns into a low-pressure gas. And during this phase change, it absorbs more heat from the air being drawn to the evaporator surface.
The Role of The Compressor
The refrigerant, thus becomes a warm and low pressure gas. But it is not warm enough to release the heat or to turn back to liquid. This is where the compressor comes in. It compresses the gaseous refrigerant making it hotter and more compressed.
Heat Rejection Through Condenser
This hot refrigerant goes through the condenser which is designed to reject heat from the system to the surrounding environment. In air-cooled condensers, fans blow outside air across the coils to carry heat away. In water-cooled or glycol-cooled condensers, the heat is transferred to water or glycol that’s circulated to a cooling tower or heat exchanger.
Refrigerant Condenses Upon Losing Temperature
The refrigerant thus loses temperature. Thus it becomes condensed into a high-pressure liquid.
The Role of Electronic Expansion Valve
This high pressure liquid passes through the Electronic Expansion Valve and it sharply loses its pressure. What happens when the pressure drops? The now-liquid refrigerant becomes cold again and enters the evaporator – starting the cycle again.
The Working Principle That Makes Precision AC a Precision AC
Tight Temperature Control
A Precision Air Conditioner is “precise” because it maintains a tighter temperature control – typically within ±1 °C – for data centers, labs, and telecom rooms. This is enabled by smart components, sensor logic, and design precision.
High Accuracy Sensors
PACs come with sensors that detect even nominal changes in temperature and provide real-time data input.
Intelligent Temperature Control
Algorithms (PID or adaptive) analyze sensor data to adjust:
- EC Fan Speed: Matches airflow to heat load. Prevents recirculation in hot/cold aisles.
- Compressor Speed: Digital compressors ramp up/down based on setpoint deviation – like self-adjusting logic.
- EEV Opening: Fine-tunes refrigerant flow and ensures vapor-only entry into condenser. Stable superheat is key.
Humidity Control
Humidity damages sensitive equipment. PACs maintain RH between 40–55% using:
- Electric/hot-gas reheat coils
- Steam humidifiers
N+1 Configuration
Redundancy is non-negotiable. PACs are deployed in N+1 configuration:
- N: Number of units needed for load
- +1: Standby unit that auto-replaces any failure
Precision ACs build on legacy cooling with adaptive intelligence, redundancy, and BMS-ready systems. This is real-time climate control, evolved.
If You’re In a Business That Requires Precision Cooling, Tempcon Is Where Your Search Stops.
Discover industrial-grade precision cooling designed for environments where failure is not an option.
Explore Tempcon Precision AC
Explore Tempcon Precision AC
