Load control system having an energy savings mode
First Claim
1. A load control system for a building having a heating and cooling system and a window located in a space of the building, the load control system comprising:
- a motorized window treatment comprising a window treatment fabric for covering the window, the motorized window treatment configured to move the fabric;
a controller configured to determine whether the heating and cooling system is heating or cooling the space, the motorized window treatment responsive to the controller;
wherein, when a calculated position of the sun relative to the window defined by a solar elevation angle (θ
S) above the horizon and a solar azimuth angle (φ
S) with respect to true north, the position calculated based on the building latitude and longitude and present date and time, indicates that the window is receiving direct sunlight, the motorized window treatment moves the fabric towards a closed position when the heating and cooling system is cooling the space, and adjusts the fabric to limit a sunlight penetration depth in the space to a maximum penetration depth when the heating and cooling system is heating the space.
1 Assignment
0 Petitions
Accused Products
Abstract
A load control system for a building having a heating and cooling system and a window located in a space of the building is operable to control a motorized window treatment in order to attempt to reduce the power consumption of the heating and cooling system. When the window may be receiving direct sunlight, the motorized window treatment closes a fabric covering the window when the heating and cooling system is cooling the space, and opens the fabric when the heating and cooling system is heating the space. In addition, when the space is unoccupied and the heating and cooling system is heating the space, the motorized window treatment may open the fabric if the window may be receiving direct sunlight, and may close the fabric if the window may not be receiving direct sunlight.
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Citations
17 Claims
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1. A load control system for a building having a heating and cooling system and a window located in a space of the building, the load control system comprising:
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a motorized window treatment comprising a window treatment fabric for covering the window, the motorized window treatment configured to move the fabric; a controller configured to determine whether the heating and cooling system is heating or cooling the space, the motorized window treatment responsive to the controller; wherein, when a calculated position of the sun relative to the window defined by a solar elevation angle (θ
S) above the horizon and a solar azimuth angle (φ
S) with respect to true north, the position calculated based on the building latitude and longitude and present date and time, indicates that the window is receiving direct sunlight, the motorized window treatment moves the fabric towards a closed position when the heating and cooling system is cooling the space, and adjusts the fabric to limit a sunlight penetration depth in the space to a maximum penetration depth when the heating and cooling system is heating the space. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of controlling a motorized window treatment comprising a window treatment fabric for covering a window in a space of the building, the building having a heating and cooling system, the method comprising:
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calculating a position of the sun relative to the window defined by a solar elevation angle (θ
S) above the horizon and a solar azimuth angle (φ
S) with respect to true north, the step of calculating based on the building latitude and longitude and present date and time;determining if the calculated position of the sun indicates that the window is receiving direct sunlight; determining whether the heating and cooling system is heating or cooling the space; adjusting the fabric to limit a sunlight penetration depth in the space to a maximum penetration depth when the calculated position of the sun indicates that the window is not receiving direct sunlight and the heating and cooling system is heating the space; and adjusting the fabric to limit the sunlight penetration depth in the space to an increased maximum penetration depth when the calculated position of the sun indicates that the window is receiving direct sunlight and the heating and cooling system is heating the space. - View Dependent Claims (11, 12)
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13. A load control system for a building having a heating and cooling system and a window located in a space of the building, the load control system comprising:
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a motorized window treatment comprising a window treatment fabric for covering the window, the motorized window treatment configured to move the fabric; a controller configured to determine whether the heating and cooling system is heating or cooling the space; and an occupancy sensor for detecting whether the space is occupied or unoccupied; wherein, when the space is unoccupied and the heating and cooling system is heating the space, the motorized window treatment moves the fabric towards an open position if a calculated position of the sun relative to the window defined by a solar elevation angle (θ
S) above the horizon and a solar azimuth angle (φ
S) with respect to true north, the position calculated based on the building latitude and longitude and present date and time, indicates that the window is receiving direct sunlight, and moves the fabric towards a closed position if the calculated position of the sun indicates that the window is not receiving direct sunlight, andwhen the space is occupied, the motorized window treatment is configured to move the fabric according to a predetermined timeclock schedule in order to limit a sunlight penetration depth in the space to a maximum penetration depth. - View Dependent Claims (14, 15, 16, 17)
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Specification