Difference Between Evaporative Cooling and Cooling Towers

What is Evaporative Cooling? What is a Cooling Tower? What’s the Difference in a Refrigeration System?
Anyone familiar with refrigeration knows that both evaporative cooling and cooling towers are common equipment types in the industry, each related to heat transfer. This article explains their differences in a refrigeration system.

1. Principles of Evaporative Cooling and Cooling Towers
Evaporative Cooling: The full name is "Evaporative Condenser." It functions as a condenser where heat transfer occurs through the evaporation of water molecules. The high-temperature, high-pressure refrigerant gas expelled from the compressor releases its heat to water molecules, which then evaporate, cooling the refrigerant and converting it into a liquid state.

The evaporative condenser consists of a cooling water circulation system, refrigerant circulation system, and electrical control system. The cooling water system typically includes a spray water tank, water pump, and fan. The refrigerant system includes the evaporator, condenser, and compressor, while the electrical control system comprises a control cabinet, temperature sensors, and water level switches.

Cooling Tower: A cooling tower is a device that cools water by using the heat exchange between water and air, effectively releasing waste heat into the air. It uses water as a circulating coolant to absorb heat from a system and discharge it into the atmosphere. Through the evaporation of water in contact with air, heat is dissipated by evaporative cooling, convection heat transfer, and radiation, lowering the water temperature to support the operation of industrial or refrigeration systems. The device is typically barrel-shaped, hence the name "cooling tower."

2. Key Differences Between Evaporative Cooling and Cooling Towers
Application and Naming Differences: Cooling towers are often associated with large water-cooled refrigeration equipment used in industrial applications. In contrast, evaporative condensers are commonly used in cold storage facilities and central air conditioning systems. Their selection and usage are generally similar.

Different Cooling Mediums: In a cooling tower, water is used as the cooling medium. An evaporative condenser, however, uses other refrigerants. The fundamental distinction is that evaporative condensers undergo a phase change (gas to liquid), while closed-loop cooling towers do not. Cooling towers only lower the temperature of the cooling medium, whereas condensers cool and condense gaseous refrigerant into a liquid state.

System Piping Differences: Evaporative condensers are connected to closed-loop systems, usually with some level of pressure. Closed-loop cooling towers can be connected to both closed and open-loop systems, often with lower or no pressure in certain operational situations.

3. Role of Evaporative Cooling and Cooling Towers in Refrigeration Systems
Both types of equipment function in heat transfer and cooling.

To simplify, condensers typically come in three forms: air-cooled, water-cooled, and evaporative. A water-cooled condenser generally includes a shell-and-tube condenser combined with a cooling tower. Therefore, in summary: an evaporative cooler is a type of evaporative condenser, one of the four major components of a refrigeration system. A cooling tower is an auxiliary component in water-cooled condensers.