Water-Cooled Condensers

Water-cooled condensers are commonly used in chillers to remove heat from the refrigerant and transfer it into a primary cooling circuit. In a recirculating chiller system, the refrigerant absorbs heat from the process or space, and transfers it to the water-cooled condenser.

Water-cooled condensers work by transferring heat from the refrigerant to the cooling water. The refrigerant enters the condenser as a high-pressure, high-temperature vapor, and flows through a series of tubes within the condenser. As the refrigerant flows through the tubes, it gives off heat to the cooler water that surrounds the tubes. This causes the refrigerant to condense from a vapor to a liquid.

The cooling water is typically supplied by a separate system, such as a cooling tower or primary water circuit, that circulates water through the condenser. The water absorbs heat from the refrigerant and exits the condenser as a warmer stream. The warmed water is then either discharged to a drainage system, or recirculated back to the cooling tower to be cooled and reused in the condenser.

Water-cooled condensers can be designed in a variety of configurations. Applied Thermal Control have selected plate-and-frame condensers, in which thin metal plates are stacked together to create a series of narrow channels through which the refrigerant and cooling water flow. This design provides a very high surface area for heat transfer in a compact space.

There are several benefits to using a water-cooled condenser in a recirculating chiller:

Higher efficiency:

• Water-cooled condensers can achieve higher levels of efficiency compared to air-cooled condensers, because water has a higher heat capacity and thermal conductivity than air. This means that a water-cooled condenser can transfer more heat from the refrigerant to the cooling water, resulting in greater cooling capacity and lower energy consumption.

Space savings:

• Water-cooled condensers can be located indoors, making them a good choice for applications where outdoor space is limited, or where noise from the chiller system must be minimized. This also means that they are less susceptible to variations in ambient temperature and humidity, which can affect the performance of air-cooled condensers.

Longer equipment life:

• Water-cooled condensers typically have a longer lifespan than air-cooled condensers, because they are not exposed to the same harsh outdoor conditions, such as wind, rain, and debris. They also require less maintenance, as they do not accumulate the same levels of dirt and debris that can clog air-cooled condensers.

Reduced noise:

• Water-cooled condensers are generally quieter that air-cooled condensers, because they do not have large fans create noise as they operate. This reduction in air movement near the chiller is particularly useful in clean room conditions. Because the heat is removed into the primary water circuit rather than into the surrounding air, it is not necessary to upgrade the building's air conditioning system. 

Greater cooling capacity:

• Water-cooled condensers can handle higher heat loads than air-cooled condensers, because water has a higher heat capacity and can absorb more heat than air. This means that they can be used in larger and more demanding applications where air-cooled condensers may not be sufficient.

While water-cooled condensers offer several benefits, there are also some drawbacks to using them in a recirculating chiller system:

Higher cost:

• Water-cooled condensers typically have a higher upfront cost compared to air-cooled condensers, due to the need for additional equipment such as a cooling tower or primary cooling circuit, pumps and piping. This can make them less cost-effective for smaller or less demanding applications.

Water consumption:

• Water-cooled condensers require a constant supply of cooling water, which can be expensive to provide and maintain. This can be a significant drawback in areas where water is scarce or where the cost of water is high. This can be mitigated with use of a primary cooling circuit, as the cooling water recirculates within a closed loop.

Maintenance:

• Water-cooled condensers require regular maintenance to ensure that the cooling water is clean and free from contaminants. This can involve regular cleaning and chemical treatments, as well as monitoring for leaks and other issues.

Complexity:

• Water-cooled condensers are more complex to install and may require additional plumbing and electrical work to connect to the cooling water supply. This can add to the installation cost and may require specialized expertise to ensure proper connection.

Water-cooled condensers are typically used in chiller systems where high cooling capacity is required and where space is limited, or outdoor installation is not feasible. However, their higher upfront cost and maintenance requirements may make them less cost-effective for smaller or less demanding applications. The decision to use a water-cooled condenser should be based on a careful analysis of the specific application and its cooling requirements. 

Water-cooled KT chillers require at least 6 liters/min cooling water at less than 25°C, with a differential pressure across the chiller of 1 bar.

Water-cooled K1, K3, K4, K6, K9 and K12 chillers require at least 10 liters/min cooling water at less than 26°C, with a differential pressure across the chiller of 1 bar.