Abstract: A method for cooling a data center having a plurality of racks and an adjustable cooling system includes the following steps. A minimum and maximum temperature is set for each of the racks. A temperature of each of the racks is determined based on i) a rate R(t) at which the chilled air at a temperature Tc is introduced to each of the racks and ii) a rate R at which warm air from each of the racks at a temperature T is returned to the cooling system. The cooling system is adjusted to add cooling or to reduce cooling to the data center. The determining and adjusting steps are repeated at a predetermined time interval to achieve and maintain the temperature of each of the racks to be greater than or equal to the minimum temperature and less than or equal to the maximum temperature.