The air-conditioning control technique based on predicted room air distribution

Conventional air-conditioning control in a roomassumes perfect diffusion of temperature in theroom, and relies on a temperature sensorinstalled on the wall or ceiling of the room, or inthe return duct. Air-conditioning is controlled sothat the sensor temperature becomes equal tothe sensor-set temperature ("set temperature").In reality, however, since thermal stratificationoccurs in a room, the set temperature is oftennot attained in an occupied zone that should beproperly air-conditioned. This may result inexcessive cooling. To siinultaneously achieveoccupant comfort and energy conservation byair-conditioning only the necessary zone to anecessary level, it is essential to baseair-conditioning control on the predicted airflowand temperature distributions in the room. Theobjective of the present study is therefore todevelop an air-conditioning control techniquethat considers such predicted distributions in theroom. In this report, computational fluiddynamics (CFD) analysis is used to study theenergy-saving effect of controlling theoccupied-zone temperature in a standardoffice-room model to the set temperature, usingvarious air-conditioning systems.