Chiller

Besides Air Handling Units and ductwork, a chiller is one of the three principal equipment in any HVAC system. Chiller delivers cold or chilled water to Air Handling Units and Fan Coil Units. The AHUs and FCUs then distribute the cold conditioned air to different parts of the building through ductwork. In addition to the above three principal equipment, there are a number of other ancillary equipment that are deployed in any HVAC project across India.

The working principle of a chiller plant is very straightforward. It supplies chilled water to the AHUs and FCUs and from there this chilled water collects unwanted heat. The whole process of supplying chilled water and collecting unwanted heat takes place in a closed loop.

There are basically two kinds of chiller systems that are used in the Indian marketplace.

Air-cooled chiller and water-cooled chiller. The main difference between the two is how the condenser is cooled. In a water-cooled chiller, the condenser is cooled by the water. Whereas in an air-cooled chiller, the condenser is cooled by the air.

Working of a water-cooled chiller

1. A water-cooled chiller generates chilled water. 
2. This chilled water is supplied to the AHUs and FCUs through the MS pipelines.
3. The filtered air in the AHUs and FCUs passes through the cooling coil.
4. The air then loses heat and this unwanted heat is collected by the chilled water in the cooling coil.
5. The cold conditioned air is supplied to the building.
6. Whereas the unwanted heat that is collected by the chilled water is returned back to the chiller through MS pipes. Therefore, a closed loop is established.
7. The unwanted heat reaches the evaporator and then it is transferred to the condenser. This happens via the refrigerant loop. A compressor or a series of compressors are used in the refrigerant loop. The compressor can be a scroll type, screw type, reciprocating type, or centrifugal type.
8. The condenser simply dumps this heat into another loop which is called the ‘condenser water loop’. This ‘condenser water loop’ runs between the condenser and a cooling tower or a series of cooling towers.
9. The ambient air in the cooling tower then collects this unwanted heat from the condenser water.
10. A fan in the cooling tower then blows away this hot air.
11. This is how the condenser in a ‘water-cooled chiller’ is cooled and therefore this kind of chiller system is termed as ‘water-cooled chiller’.

Working of an air-cooled chiller

1. Like a water-cooled chiller, an air-cooled chiller also produces chilled water.
2. Just like in a water-cooled chiller, an air-cooled chiller also incorporates step 2 to step 7.
3. The condenser in the case of an air-cooled chiller is cooled by the air that is blown by a fan.
4. This is how the condenser in an ‘air-cooled chiller’ is cooled and therefore this kind of chiller system is termed as ‘air-cooled chiller’.

Applications of water-cooled chiller and air-cooled chiller

A water-cooled chiller is used for large applications wherein the load in TR is more. For example, in a mall, hospital, large office building, hotel, airport, warehouse, etc. Whereas an air-cooled chiller is used for medium to small applications. Water-cooled chiller is ideally located in the basement or lower floor of a building. Whereas an air-cooled chiller is ideally located on the roof or in an open area adjoining the building. A water-cooled, and an air-cooled chiller use standard equipment such as pumps, MS pipework to circulate the chilled water in the loop.

TheSmartHVAC works with building owners  and only after understanding the cooling load requirements, the design team recommends either a water-cooled chiller or an air-cooled chiller.

The cooling load is estimated based on the shape, size, and the design of the building in consideration. For a relatively small building, cooling load calculations are simple and straightforward. However, for a large building such as a hotel, a mall, a hospital, an airport, the cooling load calculations are complex in nature and take weeks. Underloading will result in a bad experience for the occupants inside the building. Whereas overloading will unnecessarily increase the capital expenditure as well as operating expenditure for the client. Therefore, utmost attention is paid to the cooling load calculations during the design phase. Besides the cooling load requirements, the space constraints and budgets are also kept in mind. And after a thorough assessment, the design is submitted to the client.

Installation:

TheSmartHVAC completed a turnkey HVAC project for a mall in Ghaziabad. Since the cooling load requirements were high, the design team recommended the use of water-cooled chillers. Three chillers of 230 TR each and two chillers of 135 TR each were recommended. The project included design as well as installation. Because of the use of the water-cooled chillers, an equal number of cooling towers were installed as well. Primary pumps and secondary pumps along with the MS pipework completed the chilled water loop. Thereafter, AHUs, FCUs, and ducts were deployed to deliver the cool conditioned air inside the mall. The installation phase was successfully completed within the timeline and budget because of proper planning and design at the onset of the project. Besides the cooling part, the project also included ventilation work. Basement areas, parking areas, and all floors in the mall were planned meticulously for ventilation.

Daikin, Bluestar, Carrier, Trane India, York, Johnson controls are some of the leading suppliers of water-cooled or air-cooled chillers in India. TheSmartHVAC works with leading manufacturers to offer its clients an end-to-end HVAC solution. Design, sourcing of equipment, and installation is provided to clients irrespective of the scale of the project. In addition to executing the new greenfield chiller projects, the company also undertakes chiller maintenance, replacement work, and AMC for the chiller plants across India. Delhi NCR, Chandigarh, Jaipur, Chennai, Hyderabad, Bengaluru, Kochi, Mumbai, Pune, Kolkata are some of the markets where the company offers HVAC solutions including a chiller system. Building owners and manufactures can reach out at [email protected]