Dual unitsData center IT equipment today is predominantly air cooled. However, with rack heat loads steadily climbing, the ability for many data centers to deliver either adequate airflow rates or sufficient chilled air is now being stretched to the limit. These trends in the heat load generated from IT equipment can have detrimental side effects, such as decresed equipment availability, wasted floor space, and inefficient cooling system operation. This situation is creating a need for implementing liquid cooling solutions. The overall goals of the liquid implementations include aspects such as trasferring as much waste heat to the facility liquid cooling loop as possible, reducing the overall volume of airflow needed by the racks, and reducing processor temperatures such that increased compute performance can be achieved.This book on liquid cooling is divided into six chapters and includes definitions for liquid and air cooling as it applies to the IT equipment, describing the various liquid loops that can exist in a building that houses a data center. It also provides the reader an overview of the chilled-water and condenser water systems and an overview of datacom equipment cooling options. The book also bridges the liquid cooling systems by providing guidelines on the interface requirements between the chilled-water system and the technology cooling system and outlines the requirements of those liquid-cooled systems that attach to a datacom electronics rack and are implemented to aid in data center thermal management.This book is the fourth in a series of datacom books published by ASHRAE and authored by TC 9.9, Mission Critical Facilities, Technology Spaces, and Electronic Equipment. The other books, listed in order of publication, are Thermal Guidelines for Data Processing Environments, Datacom Equipment Power Data center IT equipment today is predominantly air cooled. However, with rack heat loads steadily climbing, the ability for many data centers to deliver either adequate airflow rates or sufficient chilled air is now being stretched to the limit. These trends in the heat load generated from IT equipment can have detrimental side effects, such as decresed equipment availability, wasted floor space, and inefficient cooling system operation. This situation is creating a need for implementing liquid cooling solutions. The overall goals of the liquid implementations include aspects such as trasferring as much waste heat to the facility liquid cooling loop as possible, reducing the overall volume of airflow needed by the racks, and reducing processor temperatures such that increased compute performance can be achieved.This book on liquid cooling is divided into six chapters and includes definitions for liquid and air cooling as it applies to the IT equipment, describing the various liquid loops that can exist in a building that houses a data center. It also provides the reader an overview of the chilled-water and condenser water systems and an overview of datacom equipment cooling options. The book also bridges the liquid cooling systems by providing guidelines on the interface requirements between the chilled-water system and the technology cooling system and outlines the requirements of those liquid-cooled systems that attach to a datacom electronics rack and are implemented to aid in data center thermal management.This book is the fourth in a series of datacom books published by ASHRAE and authored by TC 9.9, Mission Critical Facilities, Technology Spaces, and Electronic Equipment. The other books, listed in order of publication, are Thermal Guidelines for Data Processing Environments, Datacom Equipment Power Trends and Cooling Applications, and Design Considerations for Datacom Equipment Centers.