Air conditioning is used to control the ambient temperature and humidity within an occupied space. The current industry standard for air conditioners is to use vapor-compression technology. However, mechanical refrigeration (air cooling) may be used in large commercial buildings as well as residential applications. Air conditioning systems can be made more efficient with free cooling towers which use venting to cool the heat exchangers below the dew point in the surrounding air and thus allowing it to evaporate from its condensate collection areas inside the air handling unit, before being recirculated into the building’s interior. This can reduce energy consumption by about 30% compared with conventional systems that make ice or use water solutions in the process of cooling inside air.