This is an analysis of electrical and water consumption for cooling systems involving refrigeration with dry coolers, water economizers and air economizers combined with steam, ultrasonic and evaporative humidifiers on telco/data centers located at various cities throughout the United States.

Air economizers with evaporative humidifiers are the most energy efficient model, although the savings are quite small for tropical locations. Air economizers are often able to satisfy cooling requirements without any refrigeration and are also able to reduce refrigeration load for additional time. These periods when refrigeration is not required have improved reliability uptime and provide low risk opportunities for chiller plant servicing. The Air economizer system also consumes less water than water economizer or refrigeration only systems.

Water economizers are less effective than air economizers at improving energy efficiency and reducing refrigeration dependency. The modeled dry cooler did not provide any savings versus refrigeration only.

Evaporative humidifiers are more efficient than ultrasonic humidifiers and much more efficient than steam humidifiers.

Air economizers with steam humidifiers are an energy wasteful design. More power is consumed by the steam humidifiers than is saved by the air economizers.

Units: Dual