AE514 Building Controls PDF

AE514 - Building Controls AUM Control System Control System Consist of … 1. Input: A system that measures data (e.g. temperature) and feeds data to a controller. 2. Controller: Compares input t...

AE514 - Building Controls AUM Control System Control System Consist of … 1. Input: A system that measures data (e.g. temperature) and feeds data to a controller. 2. Controller: Compares input to a set point to make a change on the controlled device. 3. Controller Device: Change its state to achieve a set point. Control Loop & Control System Simple Control Loop Controller: contains a collection of control loops. to manage a system such as: Air Handling Unit (AHU) Fan Coil Unit (FCU) Chiller (Air-Cooled) Eng. Mekky Tel. 97343680 AE514 - Building Controls AUM Types of Control Loop 1. Open Control Loop : Output has no effect on the controlled variable. Non feedback control loop. Example: 1. Dryer: (It will continue until the end of the time even if the laundry is already dried). 2. Toaster: Controlled variable (output) is color of the toast. No measurement of the color of the toast. No correction made based on output. 3. Washing Machine: Controlled variable (output) is the dirt of the clothes No measurement of the clothes dirt No correction made based on the output 4. TV Remote Control: Controlled variable (output) is the chosen channel When we press any button on the remote, it will send a signal to the TV make changes The remote is not getting any signal from the TV whether any changes happen or not. 5. Cooling System: Sensor measures the outside air temperature Controller compares the value to a desired value and adjusts the valve to vary the capacity of the coil. The variation in water temperature or airflow are not considered. The air may be too hot or too cold resulting in wasted energy and poor comfort control. Eng. Mekky Tel. 97343680