There are valid reasons to choose the waterside economizer (WSE) system over its more common relative, the airside economizer. The airside economizer (ASE) takes advantage of outdoor air during cool weather to offset internal heat gains in a facility that would normally be taken care of by mechanical refrigeration. The mechanical refrigeration system often consists of one or more chillers and associated cooling towers.
A WSE generates cold water using only the cooling towers during cool weather. Both systems save energy during cool and cold weather, which is why the term economizer is used.