VIRGA III® by NIMBUS® Advanced Process Cooling is a closed circuit hybrid adiabatic cooling system. The hybrid adiabatic technology used by VIRGA III systems was born in Europe in response to widespread regulations aimed at preventing the spread of Legionnaires’ disease by replacing traditional evaporative cooling towers, one of the most common breeding grounds for Legionella bacteria.

Hybrid adiabatic cooling, as it applies to the VIRGA III, is the process of evaporation where dry air absorbs moisture, thereby dropping its temperature. This process precools the air without energy expense and cools the process fluid with a smaller, cleaner, more efficient system.

Hybrid adiabatic cooling technology is a rare example of regulation yielding a more efficient product, as the use of hybrid adiabatic cooling not only enables the VIRGA III to eliminate one of the primary breeding grounds for Legionella pneumophila, but also allows it to operate with significantly less water, little to no maintenance, and without costly water treatment chemicals when compared to traditional evaporative cooling towers.

VIRGA III Conserves Water                                                                                                                               

Rather than relying on a reservoir of standing water like typical traditional evaporative cooling towers, the VIRGA III hybrid adiabatic system uses a fine spray of water only during the hottest months of the year when process fluid and ambient air temperatures dictate. This results in up to 60-90% water savings over traditional fluid cooling towers. During cooler months, the VIRGA III operates as a dry cooling system and does not use any water to cool.

VIRGA III Protects Health                                                                                                                                    

VIRGA III eliminates the standing water found in evaporative cooling towers. This eliminates one of the primary breeding grounds for Legionella pneumophila — the bacteria that causes Legionnaires’ disease.

VIRGA III Provides Energy Efficiency                                                                                                               

VIRGA III fans turn on in stages and only run when required to maintain the desired operating fluid temperature. This results in reduced energy consumption when compared to traditional cooling systems. NEMA Premium Efficiency Motors are used in compliance with the Energy Independence and Security Act of 2007.

To learn more about NIMBUS Advanced Process Cooling, VIRGA III systems, or hybrid adiabatic cooling, please visit or call 844.NIMBUS.3.