Multipurpose controller for multistate windows
“Smart” controllers for windows having controllable optical transitions are described. Controllers with multiple features can sense and adapt to local environmental conditions. Controllers described herein can be integrated with a building management system (BMS) to greatly enhance the BMS's effectiveness at managing local environments in a building. The controllers may have one, two, three or more functions such as powering a smart window, determining the percent transmittance, size, and/or temperature of a smart window, providing wireless communication between the controller and a separate communication node, etc.
1. A window controller for controlling one or more windows capable of undergoing reversible optical transitions, the window controller comprising one or more microprocessors configured to control functions comprising:
determining a percent transmittance (% T) of at least one of the one or more windows;
actively and reversibly powering a reversible optical transition between at least a bleached end state and a colored end state of the at least one of the one or more windows, wherein:
powering is based on the determined % T of the at least one window; and
determining the % T is inferred algorithmically or measured directly using at least one sensor.
2. The window controller of claim 1 , wherein the % T is measured directly using the at least one sensor.
3. The window controller of claim 2 , wherein the sensor comprises a pyranometer.
4. The window controller of claim 3 , wherein the pyranometer measures solar irradiance across a spectrum of solar radiation.
5. The window controller of claim 2 , wherein the sensor is a photometric sensor.
6. The window controller of claim 2 , wherein the sensor is a silicon photodiode.
7. The window controller of claim 2 , wherein the at least one sensor includes a first sensor disposed in a location exterior to a building including the one or more windows and a second sensor disposed in an interior location of the building.
8. The window controller of claim 7 , wherein the % T is determined by comparing solar spectrum measurements of the first sensor and the second sensor.
9. The window controller of claim 1 , wherein
at least one of the one or more windows comprises a first conductive layer, a second conductive layer, and an electrochromic layer between the first conductive layer and the second conductive layer; and
the powering the reversible optical transition comprises applying a DC voltage to the first conductive layer and to the second conductive layer to provide an electrical potential across the electrochromic layer establishing a load, wherein the load is floated.
10. The window controller of claim 1 , wherein the one or more microprocessors are further configured to also control functions of:
communicating between the window controller and a separate communication node.
11. A method of controlling systems in a building, the method comprising:
determining transmittance data from one or more windows in the building, the transmittance data comprising a percent transmittance (% T) of at least one of the one or more windows wherein the % T is inferred algorithmically or measured directly using at least one sensor and the one or more windows are capable of undergoing reversible optical transitions between at least bleached end states and colored end states in the building; and
using the transmittance data as an input for adjusting at least one other system of the building, said other system selected from the group consisting of HVAC, lighting, security, power, fire suppression and elevator control.
12. The method of claim 11 , wherein the % T is measured directly using the at least one sensor.
13. The method of claim 12 , wherein the sensor comprises a pyranometer.
14. The method of claim 13 , wherein the pyranometer measures solar irradiance across a spectrum of solar radiation.
15. The method of claim 12 , wherein the sensor is a photometric sensor.
16. The method of claim 12 , wherein the sensor is a silicon photodiode.
17. The method of claim 12 , wherein the at least one sensor includes a first sensor disposed in a location exterior to a building including the one or more windows and a second sensor disposed in an interior location of the building.
18. The method of claim 17 , wherein the % T is determined by comparing solar spectrum measurements of the first sensor and the second sensor.
19. The method of claim 11 , wherein:
at least one of the one or more windows comprises a first conductive layer, a second conductive layer, and an electrochromic layer between the first conductive layer and the second conductive layer; and
the reversible optical transition are powered by applying a DC voltage to the first conductive layer and to the second conductive layer to provide an electrical potential across the electrochromic layer establishing a load, wherein the load is floated.
20. A window controller for controlling a window capable of undergoing reversible optical transitions, the window controller comprising:
a voltage regulator;
a voltage control amplifier for generating current to power the window; and
a microprocessor powered by the voltage regulator, the microprocessor configured to control the functions of:
powering a reversible optical transition between at least a bleached end state and a colored end state of the window based on window data received from memory embedded in the window and separate from the window controller, wherein the window data includes transmittance data, comprising a percent transmittance (% T) of the window, wherein the % T is inferred algorithmically or measured directly using at least one sensor; and
storing the window data to the memory.
21. The window controller of claim 20 , wherein the % T is measured directly using the at least one sensor.
22. The window controller of claim 21 , wherein the sensor comprises a pyranometer.
23. The window controller of claim 22 , wherein the pyranometer measures solar irradiance across a spectrum of solar radiation.
24. The window controller of claim 21 , wherein the sensor is a photometric sensor.
25. The window controller of claim 21 , wherein the sensor is a silicon photodiode.
26. The window controller of claim 21 , wherein the at least one sensor includes a first sensor disposed in a location exterior to a building including the window and a second sensor disposed in an interior location of the building.
27. The window controller of claim 26 , wherein the % T is determined by comparing solar spectrum measurements of the first sensor and the second sensor.
28. The window controller of claim 20 , wherein;
the window comprises a first conductive layer, a second conductive layer, and an electrochromic layer between the first conductive layer and the second conductive layer; and
the powering the reversible optical transition comprises applying a DC voltage to the first conductive layer and to the second conductive layer to provide an electrical potential across the electrochromic layer establishing a load, wherein the load is floated.
29. A building management system (BMS) for a building, the BMS comprising: a computer-based control system that includes one or more electrochromic (EC) windows and at least one EC window controller configured to adjust a transmissivity of the one or more of the EC windows wherein:
the computer-based control system receives data feedback, including window transmissivity data comprising a percent transmittance (% T) of the one or more EC windows, from the at least one EC window controller and, based at least in part on the window transmissivity data, manages two or more local environmental conditions of temperature, carbon dioxide levels and humidity within the building and one or both of heating energy costs and cooling energy costs for the building, wherein the % T is inferred algorithmically or measured directly using at least one sensor.
30. The window controller of claim 29 , wherein the % T is measured directly using the at least one sensor.
31. The window controller of claim 30 , wherein the sensor comprises a pyranometer.
32. The window controller of claim 31 , wherein the pyranometer measures solar irradiance across a spectrum of solar radiation.
33. The window controller of claim 31 , wherein the sensor is a photometric sensor.
34. The window controller of claim 31 , wherein the sensor is a silicon photodiode.
35. The window controller of claim 30 , wherein the at least one sensor includes a first sensor disposed in a location exterior to a building including the window and a second sensor disposed in an interior location of the building.
36. The window controller of claim 35 , wherein the % T is determined by comparing solar spectrum measurements of the first sensor and the second sensor.