In this article, technical-economical investigation of heating and cooling loads in faculty of engineering of Arak University, Iran has been investigated. The traditional and modern conditioner systems such as CAV, VAV, fan coil systems (all three systems are tested with direct fired absorption chiller and screw chiller), VRF system, split system and evaporative cooling system (in total 9 different systems) are designed for this faculty and are compared technicallyeconomically. In this article, the costs of water, electricity and gas, purchase of systems and equipment, maintenance and repair of equipment of the examined systems are calculated and are compared with each other and then this work is done in different cooling loads, so that the results are not limited to the technical faculty of Arak university and can be used for all existing systems throughout the country. In the end, it is shown, that the evaporative cooling system has the lowest current and initial cost among the other systems. However, since this systems do not have the ability to determination of the amount of humidity and ideal temperature for the desired space cannot be considered as an ideal and standard system. Also it is shown, that the current and initial costs of compression chiller are less than of absorption chiller and VAV systems have the better performance than CAV and fan coil systems, and the VRF system, after the evaporative cooling system, has the lowest current and initial cost among the examined systems, especially the split system. Due to the intelligent and optimal control of this system, it can be selected as an ideal system.