A Review on efficient thermal management of air- and liquid-cooled data centers: From chip to the cooling system

•Discussed thermal challenges of data centers.•Reviewed thermal management techniques of data centers from chip to the cooling system.•Compered various modelling and optimization methods of air-cooled data centers.•Compered technical characteristics of various direct and indirect liquid-cooled data centers.•Reviewed thermal performance of various air- and water-side economizers.