Claims
- 1. A method for maintaining a relative humidity level in a cabinet, comprising:determining a relative humidity set point; activating a heater in a fluid pan; determining if a fluid is present in said fluid pan; measuring said relative humidity and an air temperature in said cabinet; and adjusting a duty cycle of said heater in response to said air temperature to maintain said relative humidity within a predetermined range.
- 2. The method of claim 1, wherein said step of determining a relative humidity set point comprises:inputting said relative humidity set point.
- 3. The method of claim 1, wherein said step of determining if a fluid is present in said fluid pan comprises:measuring a status of a float switch.
- 4. The method of claim 1, wherein said step of maintaining said relative humidity within a predetermined range comprises:repeatedly measuring said relative humidity in said cabinet, and deactivating said heater responsive to said relative humidity within a predetermined range of said relative humidity set point; and reactivating said heater responsive to said relative humidity falling outside of said predetermined range of said relative humidity set point.
- 5. The method of claim 1, wherein said duty cycle is set at 25% when said air temperature is less than 125° F.
- 6. The method of claim 1, wherein said duty cycle is set at 31% when said air temperature is greater than 125° F.
- 7. The method of claim 3, wherein the step of measuring a status of a float switch further comprises measuring a temperature of fluid in said fluid pan and comparing said fluid temperature to a maximum allowable fluid temperature.
- 8. A system for maintaining a relative humidity level in a cabinet, comprising:means for determining a relative humidity set point; means for activating a heater in a fluid pan; means for determining if a fluid is present in said fluid pan; means for measuring said relative humidity and an air temperature in said cabinet; and means for adjusting a duty cycle of said heater in response to said air temperature to maintain said relative humidity within a predetermined range.
- 9. The system of claim 8, wherein said duty cycle is set at 25% when said air temperature is less than 125° F.
- 10. The system of claim 8, wherein said duty cycle is set at 31% when said air temperature is greater than 125° F.
- 11. A method for maintaining a relative humidity level in a cabinet, comprising:determining a relative humidity set point; activating a heater in a fluid pan; determining if a fluid is present in said fluid pan; measuring said relative humidity in said cabinet; and setting a duty cycle of said heater at 100% if said relative humidity is greater than a predetermined amount below a relative humidity set point to maintaining said relative humidity within a predetermined range.
- 12. The method of claim 11, wherein said predetermined amount is 3% relative humidity.
- 13. The method of claim 11, wherein said step of determining if a fluid is present in said fluid pan comprises:measuring a status of a float switch by measuring a temperature of fluid in said fluid pan and comparing said fluid temperature to a maximum allowable fluid temperature.
- 14. A system for maintaining a relative humidity level in a cabinet, comprising:means for determining a relative humidity set point; means for activating a heater in a fluid pan; means for determining if a fluid is present in said fluid pan; means for measuring said relative humidity in said cabinet; and means for setting a duty cycle of said heater at 100% if said relative humidity is greater than a predetermined amount below a relative humidity set point to maintaining said relative humidity within a predetermined range.
- 15. The system of claim 14, wherein said predetermined amount is 3% relative humidity.
Parent Case Info
The present application claims priority from U.S. Provisional Patent Application No. 60/217,707, entitled “Holding Cabinet with Closed-Loop Humidity Control System and Method for Controlling Humidity in a Holding Cabinet,” filed Jul. 12, 2000, and U.S. Provisional Patent Application No. 60/156,449, entitled “Holding Cabinet with Closed-Loop Humidity Control System and Method for Controlling Humidity in a Holding Cabinet,” filed Sep. 28, 1999, which are incorporated herein by reference.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0612494 |
Aug 1994 |
EP |
Non-Patent Literature Citations (1)
Entry |
McGraw-Hill, 1957 Considine, Process Controls Handbook, P 11-17& P 11-18. |
Provisional Applications (2)
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Number |
Date |
Country |
|
60/156449 |
Sep 1999 |
US |
|
60/217707 |
Jul 2000 |
US |