Focus on Chillers: Four Pipe Vs. Two Pipe Chillers

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An HVAC chiller is a system component that removes heat from liquid coolant through one of several possible processes. There are two basic configuration chiller types – 2-pipe and 4-pipe. Here, we outline how each system works and discuss each configuration’s relative merits.


2-pipe systems feature a single coil operating as the heating and cooling source. As the name suggests, this system includes one supply line and a separate return line. A 4-pipe system, on the other hand, features parallel heating and cooling systems, each with its supply and return pipes.


One benefit of the 2-pipe system is that it uses less power than the 4-pipe configuration. In addition, it takes up less physical space and is usually quicker to install. Fewer moving parts also means these systems typically require less maintenance.

In terms of drawbacks, 2-pipe systems lack versatility. These systems can only heat or cool down a building at any one time and can’t heat one room while cooling others.


Although they use more energy and require more space than the 2-pipe system, 4-pipe systems offer better flexibility and the best efficiency for large buildings. They are also much more suitable for climates that experience both hot and cold weather. This system also allows for dehumidification. The chilled water coil removes whatever moisture it can from the air while operating at maximum capacity. The hot water coil then compensates for excess cooling, resulting in air that is both the desired temperature and the correct humidity level.


The 4-Pipe chillers offered by Masterflow use the Clivet system (designed by Bruno Bellò), which was introduced in 1989 and continues to be developed and refined by Clivet’s team of engineers at their factory in Italy. These multifunction chillers are continually improved to provide maximum energy efficiency, resulting in lower operating costs and reduced carbon emissions. All chillers are ErP compliant, use refrigerant R410a, and are suitable for outdoor installation.

We realise that no two buildings are alike, and each requires its specialised HVAC system. Our specialists analyse each building’s requirements to produce a system ideal for your needs. This practice ensures the ongoing suitability of each circuit to the changing requirements of the building.

Clivet’s Multifunction chillers range in capacity from 50kw-1180kw and allow for continuous heating, cooling, and humidity control. They are available with varying specialised features, including heat recovery, onboard pumps, an onboard buffer tank, an ambient temperature range, and control interfaces such as BACnet or Modbus.


Masterflow has earned a reputation for delivering world-standard HVAC systems with an unwavering customer service focus. Our people will go above and beyond to ensure you get the system that is best suited to the specific needs of your building. To discuss your project with our team today, contact us by phone or email.