Air-cooled screw chillers have previously been known for loud operation and relatively low efficiency compared to water-cooled equipment. Recent advances by several chiller manufacturers has resulted in significantly improved efficiency and lower sound footprints. The Daikin McQuay Pathfinder chiller line provides units in three efficiency tiers, with IEER up to 19.4, in tonnages from 190 to 550.
Air-cooled equipment provides benefits over water-cooled equipment: reduced water treatment requirements and fewer equipment components. Caution is required, as equipment has a larger footprint. Units need to be installed with adequate clearance to minimize recirculation effects, which can significantly derate performance. In ASHRAE climate zones 4 through 8, anti-freeze solutions may be needed.