Patent ID: 6227961
Filing Date: 2001-05-08
Classification: F04D,F05D,F24F,Y02B

Abstract:
A fan control system suitable for use in air moving applications comprising:a pressure sensor responsive to an air pressure in a supply air duct for supplying a static pressure signal representative of the static air pressure in the supply air duct;a supply air flow sensor responsive to an air flow in a supply air duct for supplying a supply air flow signal representative of the air flow in the supply air duct;a return air flow sensor responsive to an air flow in a return air duct for supplying a return air flow signal representative of the air flow in the return air duct;a supply fan for moving air in the supply air duct, said supply fan being driven by a supply fan motor;a return fan for moving air in the return air duct, said return fan being driven by a return fan motor; anda unitary volumetric air flow controller connected to the supply fan and connected to the return fan, said air flow controller comprising:a drive controller selectively controlling the supply fan and the return fan;a process controller selectively providing a drive control signal to the drive controller in response to the static pressure signal, the supply air flow signal, and the return air flow signal, said drive controller and said process controller being mounted in a common housing; andwherein the drive controller is responsive to the drive control signal for selectively applying a supply drive power signal to the supply fan for energizing the supply fan, and for selectively applying a return drive signal to the return fan motor for energizing the return fan motor, whereby the static pressure in the supply air duct is maintained at a substantially constant pressure.