Humidity control for air conditioning system

• US 20070261422A1
• Filed: 05/10/2006
• Published: 11/15/2007
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: Trane International Inc. (Trane Technologies plc)
• Original Assignee: American Standard Companies Incorporated (Ideal Standard International Topco SCA)
• Inventors: Crawford, Roy
• Granted Patent: US 8,091,375 B2
• Time in Patent Office: Days
• US Class Current: 62/176.100
• CPC Class Codes: F24F 11/0008 for air-humidification F24F11/30 takes precedence
• 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 11/65 for selecting an operating mode
• CPC Class Codes: F24F 11/74 for controlling air flow rate or air velocity
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: G05D 22/02 characterised by the use of electric means

Abstract

In an air conditioning system for circulating cooled air to an enclosed space, a controller including a temperature sensor, a humidity sensor and a microcontroller for controlling the indoor fan or blower to prevent operation of same if a fan run-on mode is selected or continuous fan operation is selected and the humidity sensed in the enclosed space is greater than a predetermined amount. Continuous fan operation is allowed unless the humidity exceeds a user defined setpoint during an air cooling operating mode. If the humidity sensed is greater than the predetermined amount, the fan is operated only when the system is providing cooled air, such as when the system compressor is energized.

Claims

1. In an air conditioning system, including an indoor unit comprising a motor driven fan for circulating air to and from an enclosed space, said indoor unit including at least one heat exchanger for providing cooling effect to air circulating to said indoor space and a controller including user actuatable switch actuators, a microcontroller operable to provide a signal to a motor control unit for said motor, and a humidity sensor for sensing relative humidity in said enclosed space, said humidity sensor being operably connected to said microcontroller, the method comprising:

disabling operation of said fan to circulate air within said enclosed space when the relative humidity sensed by said humidity sensor is greater than a predetermined amount.

2. The method set forth in claim 1 including the step of:

operating said fan to circulate air to said enclosed space when said system is operating to provide cooled air to said enclosed space.

3. The method set forth in claim 2 wherein:

said fan is energized when a compressor of said air conditioning system is operating to circulate a refrigerant fluid to said at least one heat exchanger.

4. The method set forth in claim 1 including the step of:

disabling operation of said fan when set by a user of said system to a continuous fan operating mode if the humidity sensed by said humidity sensor is greater than said predetermined amount.

5. The method set forth in claim 1 including the step of:

causing said controller to disable operation of said fan with respect to any delay in de-energization of said fan after a cooling call is satisfied when said humidity is greater than said predetermined amount.

6. The method set forth in claim 1 including the step of:

providing a display for said controller and displaying a condition of said fan as being energized when said fan is set to a continuous fan operating mode regardless of whether or not said fan is actually operating.

7. The method set forth in claim 1 including the step of:

setting a predetermined time for periodically sensing said humidity and for disabling operation of said fan if said humidity is greater than said predetermined amount.

8. The method set forth in claim 1 including the step of:

controlling operation of said fan in relation to the humidity sensed in said enclosed space only if said fan has been enabled in a continuous operating mode by a user of said system.

9. The method set forth in claim 1 including the step of:

disabling operation of said fan only when said humidity sensor detects a humidity level in said enclosed space a predetermined amount different from a humidity setpoint set at said controller.

10. The method set forth in claim 1 including the step of:

operating said fan in accordance with a requirement of a cooling call at said controller for operation of said system to supply cooled air to said enclosed space.

15. The method set forth in claim 1 including the step of:

disabling operation of said fan only when said humidity sensor detects a humidity level in said enclosed space a predetermined amount different from a humidity setpoint set at said controller.

11. In an air conditioning system, including an indoor unit comprising a motor driven fan for circulating air to and from an enclosed space, said indoor unit including at least one heat exchanger for providing cooling effect to air circulating to said indoor space and a controller including user actuatable switch actuators, a microcontroller operable to provide a signal to a motor control unit for said motor, and a humidity sensor for sensing relative humidity in said enclosed space, said humidity sensor being operably connected to said microcontroller, the method comprising:

operating said fan to circulate air to said enclosed space when said system is operating to provide cooled air to said enclosed space; and

disabling operation of said fan when set by a user of said system to a continuous fan operating mode if the humidity sensed by said humidity sensor is greater than said predetermined amount.

12. The method set forth in claim 11 wherein:

enabling operation of said fan when a compressor of said system is operating to circulate a refrigerant fluid to said at least one heat exchanger.

13. The method set forth in claim 11 including the step of:

causing said controller to disable operation of said fan with respect to any delay in de-energization of said fan after a cooling call is satisfied when said humidity is greater than said predetermined amount.

14. The method set forth in claim 11 including the step of:

setting a predetermined time for periodically sensing said humidity and for disabling operation of said fan if said humidity is greater than said predetermined amount.

16. An air conditioning system comprising:

an indoor unit including a motor driven fan for circulating air to and from an enclosed space;

at least one heat exchanger disposed in a flow path of air circulating through said indoor unit; and

a controller operably connected to said indoor unit including a microcontroller operably connected to a humidity sensor for sensing the humidity in said enclosed space, said controller being operable to discontinue operation of said fan from at least one of a user selected fan operating mode and a selected fan de-energization delay period when the humidity sensed by said humidity sensor within said enclosed space is greater than a predetermined amount.

17. The system set forth in claim 16 wherein:

said controller includes a temperature sensor for sensing the temperature in said enclosed space and said microcontroller is responsive to a call for cooling air to be circulated through said enclosed space for enabling operation of said fan.

18. The system set forth in claim 16 wherein:

said microcontroller is operable to control the speed of said motor when said call for cooling is satisfied to provide a selected air flowrate through said indoor unit less than a full air flowrate capability of said fan when the humidity level in said enclosed space sensed by said humidity sensor is less than a predetermined amount.

19. The system set forth in claim 16 wherein:

said microcontroller is operable to disable operation of said fan upon sensing a humidity level in said enclosed space greater than a predetermined percent of a setpoint for humidity set in said controller.