Positive air pressure isolation system

• US 8,485,874 B2
• Filed: 11/29/2011
• Issued: 07/16/2013
• Est. Priority Date: 05/24/2006
• Status: Expired due to Fees

• Current Assignee: American Innovative Research Corp.
• Original Assignee: American Innovative Research Corp.
• Inventors: Palmer, David W.
• Primary Examiner(s): McAllister, Steven B
• Assistant Examiner(s): Kosanovic, Helena
• Application Number:
  US13/306,489
• Publication Number:
  US 20120071079A1
• Time in Patent Office: 595 Days
• Field of Search: 454/255, 553/852
• US Class Current: 454/255
• CPC Class Codes: A61L 9/20 Ultraviolet radiation
• CPC Class Codes: B01L 1/04 Dust-free rooms or enclosures
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 2011/0004 to create overpressure in a room
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: F24F 2110/32 of the outside air
• CPC Class Codes: F24F 2110/40 Pressure, e.g. wind pressure
• CPC Class Codes: F24F 8/108 using dry filter elements
• CPC Class Codes: F24F 8/192 by electrical means, e.g. by applying electrostatic fields or high voltages
• CPC Class Codes: F24F 8/22 using UV light
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

An air-pressure-control system, the system comprising a system inlet, a system outlet, and a variable-speed fan configured to operate at a speed. A motor controller in communication with the fan is configured to control the speed of the fan. A differential-pressure transducer configured to monitor an air pressure at the system inlet and an air pressure at the system outlet. A closed-loop pressure controller in communication with the motor controller and differential-pressure transducer, wherein the pressure controller is configured to vary the speed of the fan based on the pressure differential between the inlet and outlet of the system, thereby controlling a pressure within a space. An ultraviolet kill chamber may be disposed between the inlet and outlet to expose airborne particulate to UV radiation. The system may also have a filter located within an air-flow path between the system inlet and system outlet.

Claims

1. An air-pressure control system, the system comprising:

a system inlet;

a system outlet;

a first filter located within an airflow path between the system inlet and system outlet;

a variable-speed fan configured to operate at a speed;

a motor controller in communication with the fan and configured to control the speed of the fan;

a differential-air-pressure transducer configured to monitor an air pressure differential between the system inlet and the system outlet;

a closed-loop controller in communication with the motor controller and the differential-pressure transducer, wherein the pressure controller is configured to vary the speed of the fan based on the pressure differential between the inlet and outlet of the system, thereby controlling a pressure within a space; and

a germicidal radiation chamber located within the airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source, and wherein the airflow path is blackened to prevent UV reflection through the system inlet and system outlet.

2. An air-pressure-control system according to claim 1, wherein the closed-loop controller includes:

a microprocessor configured to compare an output from the differential pressure transducer and a setpoint value and adjust the speed of the fan based on the difference between the differential-air-pressure transducer output and the setpoint value.

3. An air-pressure-control system according to claim 2, further comprising a safety sensor in communication with the microprocessor and configured to alarm when the air-pressure-control system is not operating at the setpoint values.

4. An air-pressure-control system according to claim 1, wherein the germicidal radiation chamber further includes a reflective interior surface configured to reflect UV light produced by the UV light source.

5. An air-pressure-control system according to claim 1, wherein the germicidal radiation chamber has at least one slot providing access to the filter.

6. An air-pressure-control system according to claim 1, wherein the first filter is located at a first end of the germicidal radiation chamber.

7. An air-pressure control system according to claim 6, wherein the system includes a second filter located at a second end of the germicidal radiation chamber.

8. An air-pressure-control system according claim 1, further comprising baffles located at an least one end of the germicidal radiation chamber, wherein the baffles are configured to prevent UV from exiting the germicidal radiation chamber.

9. An air-pressure-control system according to claim 1, wherein the differential-air-pressure transducer is a hot-wire or solid state anemometer.

10. An air-pressure-control system according to claim 1, wherein the air-pressure-control system is configured for through-window installation.

11. An air-pressure-control system comprising:

a first air path including a first air path inlet and first air path outlet;

a second air path including a second air path inlet and second air path outlet;

a variable-speed fan located within the first air path and configured to operate at a speed;

a motor controller in communication with the fan and configured to control the speed of the fan;

a solid state anemometer located within the second air path and configured to monitor an air pressure differential between the second air path inlet and the second air path outlet; and

a closed-loop controller in communication with the motor controller and the solid state anemometer, wherein the closed-loop controller is configured to vary the speed of the fan based on the pressure differential between the second air path inlet and the second air path outlet, thereby controlling a pressure within a space, the closed-loop controller bringing the fan to full speed upon a change in condition within the space, the closed-loop controller then reducing the speed of the fan to obtain a setpoint value.

12. An air-pressure-control system according to claim 11, wherein the closed-loop controller includes:

a microprocessor configured to compare an output from the solid state anemometer and the setpoint value and adjust the speed of the fan based on the difference between the solid state anemometer output and the setpoint value.

13. An air-pressure-control system according to claim 12, further comprising a safety sensor in communication with the microprocessor, the microprocessor configured to alarm when the air-pressure-control system is not operating at the setpoint values.

14. An air-pressure-control system according to claim 12, further comprising:

a germicidal radiation chamber located within the first airflow path, wherein the germicidal radiation chamber includes at least one UV light source.

15. An air-pressure-control system according to claim 14, wherein the germicidal radiation chamber further includes a reflective interior surface configured to reflect UV light produced by the UV light source.

16. An air-pressure-control system according to claim 14, wherein the input and outlet of the first airflow path are blackened to prevent UV reflection through the first air path inlet and first air path outlet.

17. An air-pressure-control system according to claim 14, wherein the germicidal radiation chamber is a removable cartridge.

18. An air-pressure-control system according to claim 14, wherein the microprocessor controls the operation of the at least one UV light source.

19. An air-pressure-control system according to claim 14, further comprising at least one baffle located at an least one end of the germicidal radiation chamber, wherein the at least one baffle is configured to prevent UV light from exiting the germicidal radiation chamber.

20. An air-pressure-control system according to claim 19, wherein at least a portion of an edge of the at least one baffle is in contact with the germicidal radiation chamber.

21. An air-pressure-control system according to claim 19, wherein the at least one baffle straightens the air flow through the system.

22. An air-pressure control system according to claim 19, wherein the at least one baffle has a reflective surface facing the germicidal radiation chamber and are configured to reflect UV light produced by the UV light source.

23. An air pressure control system according to claim 14, the system further including an air flow sensor located within the germicidal radiation chamber.

24. An air pressure control system according to claim 23, wherein the air flow sensor is oriented such that it is co-linear with a flow of air through the system.

25. An air pressure control system according to claim 23, wherein the air flow sensor is a solid state sensor.

26. An air pressure control system according to claim 23, wherein the air flow sensor is in communication with the microprocessor such that the microprocessor can control the fan speed based on a signal transmitted by the air flow sensor.

27. An air pressure control system according to claim 14, the system further comprising a UV sensor located within the germicidal radiation chamber and configured to measure an amount of UV radiation.

28. An air pressure control system according to claim 27, wherein the UV sensor is located in the air flow path.

29. An air pressure control system according to claim 27, wherein the UV sensor is in communication with the microprocessor such that the microprocessor can control the fan speed based on a signal transmitted by the UV sensor.

30. An air-pressure-control system according to claim 14, wherein the air-pressure-control system is configured for through-window installation.

31. An air-pressure-control system according to claim 14, further comprising a first filter located within the airflow.

32. An air-pressure-control system according to claim 31, wherein the first filter is a HEPA filter.

33. An air-pressure-control system according to claim 31, wherein the germicidal radiation chamber has at least one slot providing access to the filter.

34. An air-pressure-control system according to claim 31, wherein the first filter is located at a first end of the germicidal radiation chamber.

35. An air-pressure control system according to claim 34, wherein the system includes a second filter located at a second end of the germicidal radiation chamber.

36. An air pressure control system according to claim 11, the system further comprising a cover having a closed and open position configured to close the first air path inlet when the system is not in use, thereby preventing airflow through the system.

37. An air pressure control system according to claim 36, the system further comprising an interlock switch connected to the cover and configured to sense a position of the cover and prevent system operation if the cover is in the closed position.

38. An air pressure control system according to claim 11, wherein the closed-loop controller includes a software port for downloading new software to the system.

39. An air pressure control system, the system comprising:

a first air path including a first air path inlet and first air path outlet;

a second air path including a second air path inlet and second air path outlet;

a variable-speed fan located within the first air path and configured to operate at a speed, the variable speed fan being reversible;

a motor controller in communication with the variable-speed fan and configured to control the speed of the variable-speed fan;

a differential-air-pressure transducer located within the second air path and configured to monitor an air pressure differential between the second air path inlet and the second air path outlet;

a closed-loop controller in communication with the motor controller and the differential-air-pressure transducer, the closed-loop controller configured to maintain a pressure in a space by varying the speed of the fan, the closed-loop controller including a microprocessor configured to compare an output from the differential-air- pressure transducer and a setpoint value, the closed-loop controller also configured to adjust the speed of the fan based on the difference between the differential-air-pressure transducer output and the setpoint value; and

a safety sensor in communication with the microprocessor and configured to alarm when the air-pressure-control system is not operating at the setpoint values a germicidal radiation chamber located within the airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source, and wherein the airflow path is blackened to prevent UV reflection through the system inlet and system outlet.

40. An air-pressure-control system according to claim 39, further comprising:

a control panel in communication with the closed-loop controller and configured to receive the setpoint value and to change the speed of the fan based on the setpoint value.

41. The air-pressure-control system according to claim 39, further comprising:

a germicidal radiation chamber located within the first airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source.

42. An air-pressure-control system according to claim 41, wherein the germicidal radiation chamber further includes a reflective interior surface configured to reflect UV light produced by the UV light source.

43. An air pressure control system according to claim 42, wherein air flow through the system is laminar, the reflective interior surface being parallel to the laminar flow.

44. An air-pressure-control system according to claim 41, wherein the first airflow path is blackened to prevent UV reflection through the system inlet and system outlet.

45. An air-pressure-control system according to claim 41, further comprising baffles located at an least one end of the germicidal radiation chamber, wherein the baffles are configured to prevent UV from exiting the germicidal radiation chamber.

46. An air-pressure-control system according to claim 39, wherein the differential-air-pressure transducer is an solid state anemometer.

47. An air-pressure-control system according to claim 39, wherein the air-pressure-control system is configured for through-window installation.

48. An air-pressure-control system according to claim 39 further comprising a first filter located within the first airflow path.

49. An air-pressure-control system according to claim 48, further comprising:

a germicidal radiation chamber located within the first airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source, the germicidal radiation chamber having at least one slot providing access to the filter.

50. An air-pressure-control system according to claim 49, wherein the first filter is located at a first end of the germicidal radiation chamber.

51. An air-pressure control system according to claim 50, wherein the system includes a second filter located at a second end of the germicidal radiation chamber.

52. An air pressure control system according to claim 39, the system further comprising a cover having a closed and open position configured to close the system inlet when the system is not in use, thereby preventing airflow through the system.

53. An air pressure control system comprising:

a housing defining the structure of the air pressure control system and configured to fit within a window of a building;

an expandable frame extending around at least part of the housing and configured to expand to at least one dimension of the window;

a first air path extending though the housing and including a first air path inlet and first air path outlet;

a second air path extending through the housing and including a second air path inlet and second air path outlet;

a variable-speed fan located within the first air path and configured to operate at a speed;

a motor controller in communication with the variable-speed fan and configured to control the speed of the variable-speed fan;

a differential-air-pressure transducer located within the second air path and configured to monitor an air pressure differential between the second air path inlet and the second air path outlet; and

a closed-loop controller in communication with the motor controller and the differential-air-pressure transducer, wherein the closed-loop controller is configured to maintain a pressure in a space by varying the speed of the fan based on the pressure differential between the air pressure at the second air path inlet and the air pressure at the second air path outlet a germicidal radiation chamber located within the airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source, and wherein the airflow path is blackened to prevent UV reflection through the system inlet and system outlet.

54. An air pressure control system according to claim 53, wherein the expandable frame includes a seal member configured to seal against at least one selected from the group consisting of a window sill, a window frame, and the housing.

55. An air-pressure-control system according to claim 53, further comprising:

a control panel in communication with the closed-loop controller and configured to receive a setpoint value and to change the speed of the fan based on the setpoint value.

56. The air-pressure-control system according to claim 53, further comprising:

a germicidal radiation chamber located within the first airflow path in the air-pressure-control system, wherein the germicidal radiation chamber includes at least one UV light source.

57. An air-pressure-control system according to claim 56, wherein the germicidal radiation chamber further includes a reflective interior surface configured to reflect UV light produced by the UV light source.

58. An air pressure control system according to claim 57, wherein air flow through the system is laminar, the reflective interior surface being parallel to the laminar flow.

59. An air-pressure-control system according to claim 56, wherein the first airflow path is blackened to prevent UV reflection through the system inlet and system outlet.

60. An air-pressure-control system according to claim 56, further comprising baffles located at an least one end of the germicidal radiation chamber, wherein the baffles are configured to prevent UV from exiting the germicidal radiation chamber.

61. An air-pressure-control system according to claim 56, further comprising an electrical chassis located within the housing, the germicidal radiation chamber being located within the electrical chassis.

62. An air-pressure-control system according to claim 61, wherein the germicidal radiation chamber is a cartridge that is removable from the electrical chassis.

63. An air pressure control system according to claim 56, the system further including an air flow sensor located within the germicidal radiation chamber.

64. An air pressure control system according to claim 63, wherein the air flow sensor is in communication with the microprocessor such that the microprocessor can control the fan speed based on a signal transmitted by the air flow sensor.

65. An air pressure control system according to claim 56, the system further comprising a UV sensor located within the germicidal radiation chamber and configured to measure an amount of UV radiation.

66. An air pressure control system according to claim 65, wherein the UV sensor is in communication with the microprocessor such that the microprocessor can control the fan speed based on a signal transmitted by the UV sensor.

67. An air-pressure-control system according to claim 53, wherein the differential-air-pressure transducer is a solid state anemometer.

68. An air-pressure-control system according to claim 53 further comprising a first filter located within the first airflow path.

69. An air-pressure-control system according to claim 68, further comprising:

a germicidal radiation chamber located within the first airflow path in the air-pressure -control system, wherein the germicidal radiation chamber includes at least one UV light source, the germicidal radiation chamber having at least one slot providing access to the filter.

70. An air-pressure-control system according to claim 69, wherein the first filter is located at a first end of the germicidal radiation chamber.

71. An air pressure control system according to claim 53, the system further comprising a cover having a closed and open position configured to close the first air path inlet when the system is not in use, thereby preventing airflow through the system.

72. An air-pressure-control system according to claim 53, wherein the closed-loop controller includes:

a microprocessor configured to compare an output from the differential-air-pressure transducer and a setpoint value and adjust the speed of the fan based on the difference between the differential-air-pressure transducer output and the setpoint value.

73. An air pressure control system according to claim 53, the system further comprising a cover having a closed and open position configured to close the first air path inlet when the system is not in use, thereby preventing airflow through the system.

74. An air pressure control system according to claim 73, the system further comprising an interlock switch connected to the cover and configured to sense a position of the cover and prevent system operation if the cover is in the closed position.