What Is a Chiller in HVAC? 

• A chiller is a machine designed to remove heat from a liquid, usually water or a water-glycol mix. 

• The chilled water is circulated through air handlers, fan coil units, or process equipment to absorb heat from the building. 

• It acts as a central cooling unit, typically found in large buildings like malls, hospitals, office towers, factories, and data centers. 

• Instead of cooling air directly, it cools water, which absorbs heat from the indoor environment through a network of pipes and air handlers.

Types of Chillers Used in HVAC Systems 

1. Air-Cooled Chillers 

• These chillers use outside air to remove heat from the refrigerant with condenser fans. 

• They are usually placed outdoors and work well for small to medium-sized buildings where space or water supply is limited. 

• They are easier to install and need less maintenance than water-cooled systems, but can be a bit less efficient in hotter climates. 

2. Water-Cooled Chillers 

• These chillers transfer heat to water, which is then cooled through a cooling tower. 

• They are often used in larger facilities or high-rise buildings because they provide greater efficiency and consistent cooling. 

• Water-cooled chillers are usually installed indoors, last longer, and perform better in high temperatures. 

3. Absorption Chillers 

• Instead of mechanical compression, these chillers use a heat source like steam, hot water, or waste heat for cooling. 

• They are eco-friendly and suitable for facilities with excess heat energy, such as manufacturing plants or power stations. 

• Though less common, they are valued for their low electricity use and smaller carbon footprint.

How Do Chillers Work? Basic Function and Operation 

1. Heat Absorption from the Building 

• Warm air inside the building moves over coils that hold chilled water. 

• The chilled water absorbs the heat, cooling the indoor air and becoming warmer in the process. 

2. Refrigeration Cycle Begins 

• The warm water returns to the chiller’s evaporator, where it meets the refrigerant. 

• The refrigerant absorbs the heat from the water, changing from liquid to gas. 

3. Heat Rejection Through the Condenser 

• The gas refrigerant is compressed, raising its temperature and pressure. 

• It then flows into the condenser, where the heat is released into air (in air-cooled systems) or water (in water-cooled systems). 

• The refrigerant then condenses back into a liquid. 

4. Continuous Cooling Cycle 

• The refrigerant passes through the expansion valve to cool down before going back into the evaporator. 

• The cooled water returns to the building to absorb more heat, continuing the cooling loop.

Where Are Chillers Commonly Used? 

• Commercial Buildings: To cool large office complexes, shopping malls, and hotels with central air conditioning systems. 

• Industrial Applications: For process cooling in manufacturing lines, chemical plants, pharmaceutical units, and food processing. 

• Healthcare Sector: Hospitals and labs rely on chillers to maintain precise temperature control for patient rooms, medical storage, and surgical environments. 

• Data Centers: Chillers prevent critical servers and equipment from overheating, ensuring data integrity and operational uptime.

Key Components of a Chiller System 

1. Compressor 

• The core of the chiller is responsible for raising the pressure and temperature of the refrigerant. 

• It moves the refrigerant through the system, enabling heat exchange. 

2. Evaporator 

• The heat exchanger where chilled water releases its absorbed heat to the refrigerant. 

• This is where the actual cooling of water takes place. 

3. Condenser 

• Removes heat from the refrigerant and releases it into the surrounding air or water. 

• Converts the refrigerant from gas back to liquid. 

4. Expansion Valve 

• Lowers the pressure of the refrigerant before it re-enters the evaporator, getting it ready to absorb more heat. 

• Regulates the flow and temperature of the refrigerant. 

5. Cooling Tower (for water-cooled chillers) 

• Releases the heat absorbed by the water-cooled chiller into the open air. 

• Plays a key role in improving the overall efficiency of the system.

Advantages of Using Chillers in HVAC Systems 

• High Efficiency: Chillers provide better cooling capacity for large buildings compared to multiple small AC units. 

• Energy Saving: Modern chillers come with variable-speed drives, BMS connectivity, and eco-friendly refrigerants that lower operational costs. 

• Consistent Climate Control: Ideal for keeping stable indoor environments, especially where precision is important. 

• Customizable Design: Chiller systems can be tailored to fit different building sizes, layouts, and cooling needs. 

• Long-Term Investment: While the initial setup can be costly, chillers offer reliable performance and low lifetime costs with proper maintenance.

Tips for Choosing the Right Chiller System 

• Analyze Cooling Load Requirements: Use heat load calculations to figure out the capacity (in tons or kW) you need for your space. 

• Consider the Type of Building: Choose air-cooled for simplicity and water-cooled for efficiency, especially in high-rise or large buildings. 

• Check Energy Efficiency Ratings: Look for chillers with high EER (Energy Efficiency Ratio) and COP (Coefficient of Performance). 

• Maintenance Accessibility: Pick models that allow easy access to filters, coils, and control panels for simpler upkeep. 

• Smart Features & Compatibility: Ensure they work with BMS or IoT platforms for better monitoring and automation.  

Why Choose Alviz Electro India Pvt. Ltd. for Chiller Solutions? 

• Turnkey Expertise: From design and selection to installation and after-sales service, Alviz provides complete HVAC solutions. 

• Custom Solutions: We evaluate your infrastructure and cooling needs to suggest the best chiller systems. 

• Eco-Conscious Approach: Our chillers are chosen for high efficiency, lower carbon emissions, and minimal energy use. 

• Diverse Industry Experience: We have successfully provided chiller solutions to retail, healthcare, industrial, and IT sectors. 

• 24/7 Support & AMC Plans: Trust our certified HVAC professionals for reliable maintenance, upgrades, and system audits. 

Conclusion: Chillers Are Central to Efficient Cooling Systems 

Chillers play a key role in modern commercial HVAC systems. They provide powerful and reliable cooling. They also offer long-term cost savings and environmental benefits. Whether you need effective air conditioning for a shopping mall or precise cooling for sensitive equipment, chillers provide practical and sustainable solutions. If you’re looking to install or upgrade your cooling system, work with Alviz Electro India Pvt. Ltd.—a trusted name in HVAC technologies across India.