Hitachi Set Free Front Flow Series



Core Technologies

High Pressure Compressor

Precise Inverter Control

2-Stage Oil Separation

1.High Efficiency Scroll Compressor

In 1983, Hitachi invented the first air conditioning scroll compressor in the world and owned the patent.

In 2003, Hitachi promoted the first high-pressure chamber scroll compressor in the industry which has the function of interior oil separating.

In 2008, Hitachi applied the cutting-edge large capacity scroll compressor to SET-FREE Central Air Conditioning system.

2.High-Pressure Chamber DC Scroll Compressor


● Sufficient Lubricating Oil Ensures Reliable Performance

● Lower Superheat Degree of Suction Gas, Higher Volume Efficiency

● Proper Oil Temperature is Ensured

● High Compression Ratio Contributes to Good Heating Capacity

● Lower Compressor Noise Level is Achieved

3.Hitachi Patented Inverter Control

Precise Inverter Control

The operating speed of DC motor in compressor can be adjusted continuously in 1Hz increment and freely relating to the variability of system capacity.

4. 2-Stage Oil Separating Technique

Detail Introduction

●S/F Modular Type


- Common Technical Features

- FSN6Q&FSDNQ Series

●S/F Front Flow Type

(IVX mini  Set-Free Mini)

●S/F Water Source Type


2-Stage Super-cooling Technique

● Two-stage super-cooling circulation enhances cooling capacity

● Pressure loss of refrigerant flowing in pipe is reduced

● Improved super cooling contributes to stable operation of EEV

● Improved super cooling allows extension of total piping length

Common Technical Features

DC Fan Motor and 25-Step Fan Speed Control

Hitachi Patented Pressure Defrosting Mode

Intelligent Demand Control

Self-demand Control

A newly developed self-demand function  largely improves energy-saving effects. Since the current is self-detected and demand control performs automatically, no signal wiring work is required.

Wave Mode Control

Wave mode turns demand control ON and OFF alternately. Instead of stuffy interior environment, the system can offer maximum comfort at the expense of minimum power consumption.

Oil-equalization Control Technology Between Outdoor Units

Synthetic application of scroll compressor with internal oil separating function,

efficient external oil separator, accumulator, and intelligent oil level control

technology regulates the oil level within the proper range, ensures oil balance

between outdoor units, and guarantees system stability and reliability.

Design and Installation

-Flexible Placement

Top-Class External Static Pressure: 60Pa

Layered Installation for Highrise Building

● Sound Ventilation and Heat Transfer

Compact and Lightweight Design

● Transportation and Handling with Elevator

● Save installation

Simple and Convenient Wiring Work

One H-LINKII system can support max.64 outdoor units and 160 indoor units.

Flexible Refrigerant Piping Work (FSN6Q&FSDNQ)