Nowadays, use of air-to-air heat recovery system combined to the cooling system is becoming necessary. Types of combination heat recovery and air conditioner must provide the comfort conditions and better indoor air quality for occupants in any climatic conditions. In this research, four types of air conditioning systems are evaluated experimentally. In each case, the amount of energy consumption by the aim of providing the thermal comfort, for various outdoor climatic conditions in hot and humid regions is evaluated and compared. The contour plot of each experimental case is made, which shows the net energy consumption of systems based on the outdoor design condition. Finally, according to the experimental results, for selected hot and humid cities of Asia's south and west countries (such as Abadan, Kuwait, Doha, Dehli, Bangkok), the rate of energy consumption of each cooling systems is calculated. It is shown that by using the heat recovery, energy consumption will reduce about 11-32% based on the system approach. (C) 2012 Elsevier B.V. All rights reserved.