What is the working principle of an Evaporative Air Cooler Chiller?

An Evaporative Air Cooler Chiller is an energy-saving refrigeration device that uses the principle of water evaporation to absorb heat. It converts hot air into cool and moist airflow by absorbing ambient heat during the evaporation of water. Compared with traditional compression air conditioners, this cooling method has significant advantages such as low energy consumption, good environmental protection, and easy installation. It is particularly suitable for dry and hot climates.

1. Core scientific principles
The evaporative cooling effect is the basic working principle of an Evaporative Air Cooler Chiller. When liquid water evaporates into water vapor, it needs to absorb a large amount of latent heat of vaporization. Under standard atmospheric pressure, about 2260 kilojoules of heat are absorbed for every kilogram of water evaporated. This heat is directly obtained from the air flowing through the wet curtain, resulting in a significant drop in air temperature. From a thermodynamic point of view, this process belongs to an adiabatic humidification and cooling process. The initial state of the air is expressed in dry-bulb temperature and wet-bulb temperature. After contacting the water film, the water evaporates and absorbs sensible heat to reduce the air temperature. At the same time, the water enters the air to increase the humidity, and finally the air temperature is close to the wet-bulb temperature.

Theoretically, the maximum cooling range is equal to the dry-bulb temperature difference. In practical applications, the key parameters that affect efficiency include the ambient dry-bulb temperature difference, air flow rate, evaporation medium efficiency, and water temperature. Under the conditions of air flow rate of 2-3 m/s and normal temperature water, high-quality evaporation medium can achieve 80-90% evaporation efficiency.

2. System structure and component functions
The Evaporative Air Cooler Chiller is mainly composed of three functional modules. The air circulation system adopts a centrifugal fan and an air guide wheel design, which can provide an adjustable air volume of 200-3000 cubic meters per hour; the water circulation system includes a 75-liter large-capacity water tank and a water pump with a flow rate of 350 liters per hour, which supports 8-10 hours of continuous operation; the core of the evaporative cooling system is the 5090 honeycomb wet curtain. This 100 mm thick special material can provide a huge evaporation area of ​​50 square meters per cubic meter.

The electrical control system integrates safety devices such as overload protection and water level sensors to ensure the stable operation of the 450-watt motor. Among the key components, the wet curtain uses Swedish patented paper corrugated laminate, which has a water absorption rate of more than 200 g/m2 and Class A anti-mildew performance; the water pump system is equipped with a 1.2-meter head and a flow rate of 6 liters/minute, and an integrated water level float valve to achieve automatic water replenishment; the fan system provides a three-speed speed regulation function, with a maximum speed of 1500 rpm, while controlling the operating noise below 55 decibels.

3. Complete Workflow
During the equipment startup phase, water needs to be filled to the 75-liter mark, and the wet curtain needs to be soaked for 30 minutes for the first use to ensure full moistening. After connecting to a 220-volt 50-Hz power supply, the water pump will start with a delay of 3 seconds to avoid the risk of dry burning. The air path during normal operation is: external hot air enters through the air inlet grille, flows through the moist wet curtain evaporation area after preliminary purification by the filter, and finally the cooled air is sent out from the air outlet.

In the water circulation, the water in the water tank is pumped to the water distributor, evenly distributed to the top of the wet curtain, and then flows through the entire wet curtain surface by gravity. The unevaporated water flows back to the water tank for reuse. During the heat exchange process, the contact time between the air and the water film on the surface of the wet curtain is controlled at 0.1-0.3 seconds. Under the conditions of ambient temperature of 35 degrees Celsius and relative humidity of 30%, different gears can achieve a temperature drop effect of 3-7 degrees Celsius. The equipment is also equipped with multiple protection mechanisms, including a water level sensor with an accuracy of ±3 mm, a temperature control switch triggered at 85 degrees Celsius, and an anti-overflow design with automatic drainage of more than 90 liters.

4. Performance characteristics analysis
Evaporative coolers have outstanding performance in energy efficiency, and their energy efficiency ratio (COP) can reach 10-15, which is 3-5 times that of traditional air conditioners. An input power of 450 watts can generate a cooling capacity of 4000-5000 watts, which is more than 70% energy saving compared to the power consumption of about 1200 watts of a 1.5-horsepower air conditioner. In terms of environmental adaptability, the best effect is achieved in arid climates with a relative humidity of less than 40%, and a temperature drop of 8-12 degrees Celsius can be achieved; in semi-humid climates (humidity 40-60%), the effect is moderate, with a temperature drop of 5-8 degrees Celsius; and in high-humidity climates (humidity over 60%), the effect is relatively limited, with a temperature drop of only 2-4 degrees Celsius.

In terms of spatial applicability, it is recommended that residential environments be configured with a standard of 15-25 square meters per unit and 30-50 square meters for industrial sites. The installation location should be selected at a height of 1.5-2 meters from the ground, avoiding direct sunlight and ensuring at least 50 cm of air intake space on both sides.

5. Maintenance and Optimization
Daily maintenance is essential to maintain equipment performance. It is recommended to drain the remaining water every day to prevent bacterial growth, clean the water tank with a 1:100 white vinegar solution every week, check the scale of the wet curtain every month, and replace it when the scale coverage exceeds 30%. The lubrication condition of the motor bearing should also be checked before use every season. In terms of water quality requirements, the ideal value of total dissolved solids (TDS) should be less than 200ppm, and the limit should not exceed 500ppm; the pH value should be kept within the range of 6.5-7.5, and the hardness should be controlled below 100 mg/L. If necessary, softened water can be used or special water treatment agents can be added. Common fault treatments include: the cooling effect is reduced due to the blockage of the wet curtain or the accumulation of scale, which can be soaked and cleaned with 5% citric acid solution; abnormal noise usually comes from the lack of oil in the fan bearing, and SAE20 oil needs to be added; water leakage is mostly caused by the aging of the sealing ring, which can be solved by replacing the silicone sealing ring.