The Data Centre air conditioners shall be designed specifically for Data Centre environmental control. It shall function by automatically monitoring and controlling the heating, cooling, humidifying, dehumidifying and filtering for the facility. 

Humidity is the amount of water vapour in an air sample. In the data center, normally humidity parameters are kept between 45% and 55% Relative Humidity. To much humidity, water may begin to condense on internal components, while to little humidity static electricity may damage components.