ENERGY EFFICIENT SYSTEMS AND STRATEGIES FOR HEATING,VENTILATING,AND AIR CONDITIONING(HVAC)OF BUILDINGS

INTRODUCTION The heating,ventilating,and air conditioning(HVAC)systems maintain and control temperature and humidity levels to provide an adequate indoor environment for people activity or for processing goods.The cost of operating an HVAC system can be signifi cant in commercial buildings and in some industrial facilities.In the U.S.,it is estimated that the energy used to operate HVAC systems can represent about 50%of the total electrical energy use in a typical commercial building(Krarti,2000).It is therefore important that buildings designers recognize some of the characteristics of the HVAC systems and determine if any available design and operating options can be considered to improve the energy of these systems.