What is Evaporative cooling?
Evaporative cooling uses the phase change of water to lower an air or water temperature before heat leaves the site. In a direct system, water evaporates into supply air. In an indirect system, a heat exchanger keeps the wetted exhaust stream apart from data-hall air. Cooling towers apply the same principle to a facility-water loop. The architecture fits climates and sites where wet-bulb temperatures are favorable and water use is acceptable. It can reduce compressor runtime, but performance falls during humid weather and annual water demand includes evaporation, drift, and blowdown. A facility needs a reliable water source, treatment, filtration, drainage, freeze protection, plume and noise review, biological controls, and permits for intake and discharge. Direct systems also need tight humidity and contaminant control. Ask for hourly energy and water models using the site's weather file, information-technology load profile, water quality, and required supply temperature. Check capacity on the design wet-bulb day and during water-treatment or fan outages. Procurement should state cycles of concentration, chemicals, legionella controls, drift limits, maintenance access, and meter locations. Compare with dry or hybrid rejection on total annual energy, peak power, potable-water exposure, and operating risk. Munters' cited page supports the data-center application, but it does not establish one universal efficiency or water-saving figure.