Collection: Evaporative Cooling
In an air conditioning system, the heat removed by chillers and drycoolers decreases as the outside temperature increases: in summer, evaporative cooling can often be exploited to improve the operating conditions of the system.
Most chiller and drycooler installations are actually sized based on the maximum outside temperature: the influence of this factor has grown in recent years in response to intense summer heatwaves. Oversizing of devices means more pollution, higher noise levels and extra investment in terms of heat exchange surface area, which is not used during periods when demand is lower.
Evaporative coolers increase system operation in these specific conditions. Carel offers pumping and distribution systems that spray finely atomized water into the air stream flowing through the coils. These water droplets evaporate spontaneously, absorbing energy from the air which is consequently cooled and comes into contact with the finned coil at a lower temperature. In this way, the heat exchanger can dissipate the nominal amount of heat even when the weather is warmer than expected. Furthermore, the atomized water particles do not evaporate completely before reaching the finned coil and consequently the heat exchanger fins are wetted, further increasing the overall efficiency of the system. The atomizers used for evaporative cooling applications can operate with untreated mains water or demineralized water and are very simple to manage: all that is needed is a pressure switch in the refrigerant circuit.
In a typical system designed to operate at an outside temperature of 26°C and a relative humidity of 50%, when using evaporative cooling, at 30°C a drycooler has an equivalent capacity to operate at 25°C without evaporative cooling. Assuming then that variable speed fans are available, controlled by an inverter, the system can achieve even higher levels of efficiency, even at low temperatures.
Compared to evaporative cooling systems that do not use atomized water, e.g. wetted media, this system has several benefits: easy installation, even in retrofit applications, more precise control with lower water consumption, lower maintenance costs and no pressure drop in the ventilation system.
