System for controlling energy through window

Abstract

Energy control system for a window comprises fenestration blinds, horizontal or vertical, disposed at the window and adjustable in angle to control solar radiation entering the window. First and second photovoltaic sensors are disposed proximate respective exterior and interior sides of the fenestration blinds for providing a signal representative of incident solar radiation at the respective exterior and interior sides. An electrical motor is can be disposed proximate the window and is operably connected to the fenestration blinds in a manner to controll the angle thereof. A microprocessor control device is provided for providing control signals to the motor to adjust the angle of the fenestration blinds. In a summer mode of operation, the microprocessor compares a ratio of the signals representative of solar radiation incident at the exterior and interior sides in response to adjustment of the angle and a preset ratio stored in the microprocessor representative of minimum direct light and maximum indirect light entering the window and continiues to provide control signals to the motor to adjust the angle until the ratio of the signals approximates the preset ratio. In the winter mode of operation, the microprocessor compares a signal representative of solar radiation incidient on the second, inner photovoltaic sensor only in response to adjustment of the fenestration angle and a preset signal representative of maximum direct light entering the window (where the fenestration angle is generally equal to the solar zenith angle) and continues to provide control signals to the motor until the signal approximates the preset signal.

Dependencies are inferred from the claim text.