An energy-efficient air-conditioning system with an exhaust fan integrated with a supply fan

An all-air central air-conditioning system with an exhaust fan incorporated with a supply fan is presented in this article. With the proposed system, detailed year-round energy-efficient operation strategies and control methods for the air-handling unit are presented. Further, the method of determining the pressure head and air volume of the exhaust fan is also presented, which is needed for designing this presented system. As opposed to conventional one supply-fan systems in the all-air central air-conditioning system, the proposed system is shown to not only maintain indoor pressurization required for controlling indoor air quality but also operate in an improved energy-efficient manner, achieved by having proper variable fresh-air ratios during the period of intermediate season. Due to its increased outdoor air, the proposed system can improve indoor air quality further.