An educational building located in the Caribbean area of Colombia that uses a VAV system has been monitored in order to quantify the energy consumption. The energy values attained has been compared with a simulation of the building running with a constant volumetric flow system. The results show that a 43% and 18% energy reduction can be achieved for the ventilation system and for the entire air conditioning system that includes a chiller with variable primary pump, a variable air volume system and a variable cooling tower fan.