Mitigating thermal shock in tintable windows

• US 10,254,618 B2
• Filed: 11/11/2016
• Issued: 04/09/2019
• Est. Priority Date: 10/21/2011
• Status: Active Grant

• Current Assignee: View Incorporated
• Original Assignee: View Incorporated
• Inventors: Parker, Ronald M.
• Primary Examiner(s): Tra, Tuyen
• Application Number:
  US15/349,860
• Publication Number:
  US 20170123286A1
• Time in Patent Office: 879 Days
• Field of Search: 359275, 359265, 345105, 345204
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 3/66 Units comprising two or more parallel glass or like panes permanently secured together reforming and uniting glass sheets by fusing C03B23/00; joining glass to glass or to other materials C03C27/00; laminated glass B32B17/10
• CPC Class Codes: E06B 3/6715 specially adapted for increased thermal insulation or for controlled passage of light E06B3/66323 takes precedence; coating of glass pains C03C17/00; devices or arrangements for controlling the intensity, colour, phase, polarisation or direction of light G02F1/00
• CPC Class Codes: E06B 3/6722 with adjustable passage of light
• CPC Class Codes: E06B 7/28 Other arrangements on doors or windows, e.g. door-plates, windows adapted to carry plants, hooks for window cleaners edge protecting devices for door leaves E06B3/88; special glazing; emergency glazing; double glazing E06B3/66
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor

Abstract

Tintable optical components such as windows are provided with a controller designed or configured to control the tinting in a manner that resists exposure to damaging thermal shock. The controller determines that a trigger condition for thermal shock is occurring or is about to occur and takes steps to avoid damaging thermal shock. In some cases, these steps include increasing the transmissivity of the optical component or holding the component in a highly transmissive state. In some cases, the steps involve heating the component.

Claims

1. A method of reducing a likelihood of thermal shock in an electrochromic window, the electrochromic window in communication with a controller configured for sending control signals to the electrochromic window, the method comprising:

determining that a trigger condition is likely to induce thermal shock in the electrochromic window in a first tint state at a particular time, wherein the trigger condition is a rapid change in radiation flux striking the electrochromic window, a rapid change in ambient temperature on an exterior face of the electrochromic window, or a pre-determined temperature difference between the environment proximate one side of the electrochromic window and the environment proximate the other side of the electrochromic window, and wherein the particular time is either at or about sunrise, or, at or near a predicted change in weather conditions; and

in response to the determination, sending a first signal from the controller to the electrochromic window to transition the electrochromic window from the first tint state to the second tint state that reduces the likelihood that the trigger condition induces thermal shock.

2. The method of claim 1, further comprising:

determining that the trigger condition has passed; and

sending a second signal to transition the electrochromic window to a third tint state, not the same as the second tint state.

3. The method of claim 1, wherein the second tint state has a transmissivity that is lower than the first tint state.

4. The method of claim 1, wherein the second tint state has a transmissivity of at least 40%.

5. The method of claim 1, further comprising causing a heating of at least a portion of the electrochromic window.

6. The method of claim 5, wherein the heating is by resistive heating of a coating of the electrochromic window by applying a current to the coating.

7. The method of claim 6, wherein the coating is a transparent conductive layer.

8. The method of claim 6, wherein the current is delivered in an oscillatory fashion.

9. The method of claim 5, wherein the heating is by resistive heating of one of the transparent conductive layers of an electrochromic device coating of the electrochromic window.

10. The method of claim 1, wherein the electrochromic window has a solid-state electrochromic device coating.

11. The method of claim 10, wherein the electrochromic window comprises a pane of untempered glass with the solid-state electrochromic device coating thereon.

12. A control system for reducing a likelihood of thermal shock in an electrochromic window, the control system comprising:

a controller configured to

determine that a trigger condition is likely to induce thermal shock in the electrochromic window at a particular time, wherein the trigger condition is a rapid change in radiation flux striking the electrochromic window, a rapid change in ambient temperature on an exterior face of the electrochromic window, or a predicted temperature difference between the environment proximate one side of the electrochromic window and the environment proximate the other side of the electrochromic window, and wherein the particular time is either at or about sunrise, or, at or near a predicted change in weather conditions, and

cause the electrochromic window to transition the electrochromic window from a first tint state to a second tint state that reduces the likelihood that the trigger condition will induce thermal shock in the electrochromic window.

13. The system of claim 12, wherein the electrochromic window comprises a pane of untempered glass.

14. The system of claim 13, wherein the electrochromic window comprises a solid-state and inorganic electrochromic coating on the pane of untempered glass.

15. The system of claim 12, wherein the second tint state has a transmissivity that is lower than the first tint state.

16. The system of claim 12, wherein the controller is further configured to heat at least a portion of the electrochromic window.

17. The system of claim 12, wherein the second tint state has a transmissivity of at least 40%.

18. The system of claim 12, wherein the electrochromic window in the second tint state has a transmissivity that is lower than in the first tint state.

19. A method of reducing a likelihood of thermal shock in an electrochromic window, the electrochromic window in communication with a controller configured to send signals to the electrochromic window to transition tint state and/or heat the electrochromic window, the method comprising:

determining that a trigger condition is likely to induce thermal shock in the electrochromic window at a particular time; and

in response to the determination, sending a signal from the controller to the electrochromic window to cause the electrochromic window to transition from a first tint state to a second tint state and/or to cause resistive heating of a coating of the electrochromic window, wherein resistive heating is caused by applying current to a transparent conductive layer disposed on a pane of the electrochromic window.

20. The method of claim 19, wherein:

the trigger condition is a rapid change in radiation flux striking the electrochromic window, a rapid change in ambient temperature on an exterior face of the electrochromic window, or a predicted temperature difference between the environment proximate one side of the electrochromic window and the environment proximate the other side of the electrochromic window, and

the particular time is at or about sunrise, or, at or near a predicted change in weather conditions.

21. The method of claim 19, wherein the transparent conductive layer is one of two transparent conductive layers of a solid-state electrochromic device coating disposed on the pane of the electrochromic window.

22. The method of claim 21, wherein the pane is of untempered glass.

23. The method of claim 21, wherein applying current to the transparent conductive layer includes applying the current to a bus bar in contact with the one of two transparent conductive layers of the solid-state electrochromic device coating.

24. The method of claim 19, wherein the second tint state has a transmissivity of at least 40%.

25. The method of claim 19, wherein the current applied is delivered in an oscillatory fashion.