Humidity control for regulating compressor speed

• US 5,129,234 A
• Filed: 01/14/1991
• Issued: 07/14/1992
• Est. Priority Date: 01/14/1991
• Status: Expired due to Term

• Current Assignee: Lennox Manufacturing Inc. (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Alford, Malcolm L.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US07/641,453
• Time in Patent Office: 547 Days
• Field of Search: 62/228.4, 62/176.6, 62/176.3
• US Class Current: 62/176.6
• 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 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/75 for maintaining constant air flow rate or air velocity
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 11/77 by controlling the speed of ventilators
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 11/86 by controlling compressors within refrigeration or heat pump circuits
• CPC Class Codes: F24F 11/88 Electrical aspects, e.g. circuits
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: G05D 22/02 characterised by the use of electric means

Abstract

A control for regulating relative humidity in an enclosure including a thermostat, a relative humidity sensor, a refrigeration compressor and an air blower. The compressor is run at low or high speeds in response to thermostat demand. Whenever the relative humidity is excessive the compressor low speed control is overridden to effect high compressor speed.

Claims

1. A control for regulating humidity in an enclosure to be used in conjunction with an air processing system, including a thermostat, an air processor and a blower, for providing processed air to said enclosure;

said thermostat providing, under predetermined conditions, a first stage cooling demand signal and a second stage cooling demand signal;

said air processor including a compressor operable in a cooling mode, in an ON cycle and an OFF cycle, and at a low compressor speed and a high compressor speed in response to said thermostat;

comprising, in combination;

sensor means for sensing actual relative humidity within said enclosure and providing a relative humidity signal;

selector means for selecting a desired relative humidity level within said enclosure and providing a set point signal; and

compressor control means, coupled and responsive to said thermostat, said sensor means and said selector means, for overriding said first stage cooling demand signal and effecting said high compressor speed in a predetermined ON cycle of said compressor whenever actual relative humidity within said enclosure exceeds said desired relative humidity level, said compressor control means including;

adjustment means, coupled to said selector means, for receiving said set point signal and for responsively providing an adjusted signal corresponding to a relative humidity threshold exceeding said desired relative humidity by a predetermined increment first comparator means, coupled to said sensor means and said selector means, for receiving said relative humidity signal and said set point signal and for responsively providing a first comparator signal whenever actual relative humidity exceeds desired relative humidity level;

second comparator means, coupled to said sensor means and said adjustment means, for receiving said relative humidity signal and said adjusted signal and for responsively providing a second comparator signal whenever actual relative humidity exceeds said relative humidity threshold; and

override means, coupled to said thermostat, said first comparator means and said second comparator means, for receiving said first stage demand signal, said first comparator signal and said second comparator signal and for responsively effecting said high compressor speed.

2. A control as claimed in claim 1 wherein said compressor control means overrides whenever said desired relative humidity level is exceeded during a compressor cycle prior to said predetermined ON cycle.

3. A control as claimed in claim 1 or 2 wherein said compressor control means establishes a relative humidity threshold above said desired relative humidity level in response to said set point signal, said compressor control means overriding said first stage cooling demand signal and effecting said high compressor speed during said ON cycle whenever said actual relative humidity exceeds said relative humidity threshold.

4. A control for regulating humidity in an enclosure to be used in conjunction with an air processing system, including a thermostat, an air processor and a blower, for providing processed air to said enclosure;

said thermostat providing, under predetermined conditions, a first stage cooling demand signal, a second stage cooling demand signal, and a reversing valve signal;

said air processor including a compressor operable in a cooling and heating mode, in an ON cycle and an OFF cycle, and at a low compressor speed and a high compressor speed in response to said thermostat;

comprising, in combination;

sensor means for sensing actual relative humidity within said enclosure and providing a relative humidity signal;

selector means for selecting a desired relative humidity level within said enclosure and providing a set point signal;

compressor control means, coupled and responsive to said thermostat, said sensor means and said selector means, for overriding said first stage cooling demand signal and effecting said high compressor speed in a predetermined ON cycle of said compressor whenever actual relative humidity within said enclosure exceeds said desired relative humidity level; and

disable means, coupled and responsive to said thermostat, for disabling said control during said heating mode.

5. A control as claimed in claim 4 wherein said compressor control means overrides whenever said desired relative humidity level is exceeded during a compressor cycle prior to said predetermined ON cycle.

6. A control as claimed in claim 4 or 5 wherein said disable means further includes a flip-flop coupled to said thermostat, said controllably conductive means including a transistor coupled to said sensor means and controlled by said flip-flop.

7. A control as claimed in claim 4 or 5 wherein said disable means includes controllably conductive means, coupled to said sensor means, for disabling said sensor means during said heating mode.

8. A control for regulating humidity in an enclosure to be used in conjunction with an air processing system, including a thermostat, an air processor and a blower, for providing processed air to said enclosure;

said thermostat providing, under predetermined conditions, a first stage cooling demand signal and a second stage cooling demand signal;

said air processor including a compressor operable in a cooling mode, in an ON cycle and an OFF cycle, and at a low compressor speed and a high compressor speed in response to said thermostat;

said blower having a first speed during said cooling mode and a second speed below said first speed;

comprising, in combination;

sensor means for sensing actual relative humidity within said enclosure and providing a relative humidity signal;

selector means for selecting a desired relative humidity level within said enclosure and providing a set point signal;

compressor control means, coupled and responsive to said thermostat, said sensor means and said selector means, for overriding said first stage cooling demand signal and effecting said high compressor speed in a predetermined ON cycle of said compressor whenever actual relative humidity within said enclosure exceeds said desired relative humidity level; and

blower control means, coupled and responsive to said thermostat and said compressor control means, for overriding said first and second stage cooling demand signals and effecting said second speed whenever said actual relative humidity exceeds said desired relative humidity level.

9. A control as claimed in claim 8 wherein said compressor control means overrides whenever said desired relative humidity level is exceeded during a compressor cycle prior to said predetermined ON cycle.

10. A control as claimed in claim 8 or 9 wherein said compressor control means includes:

adjustment means, coupled to said selector means, for receiving said set point signal and for responsively providing an adjusted signal corresponding to a relative humidity threshold exceeding said desired relative humidity by a predetermined increment;

first comparator means, coupled to said sensor means and said selector means, for receiving said relative humidity signal and said set point signal and for responsively providing a first comparator signal whenever actual relative humidity exceeds desired relative humidity level;

second comparator means, coupled to said sensor means and said adjustment means, for receiving said relative humidity signal and said adjusted signal and for responsively providing a second comparator signal whenever actual relative humidity exceeds said relative humidity threshold; and

override means, coupled to said thermostat, said first comparator means and said second comparator means, for receiving said first stage demand signal, said first comparator signal and said second comparator signal and for responsively effecting high compressor speed.

11. A control for regulating humidity in an enclosure to be used in conjunction with an air processing system, including a thermostat, an air processor, a humidifier and a blower, for providing processed air to said enclosure;

said thermostat providing, under predetermined conditions, a first stage cooling demand signal and a second stage cooling demand signal;

said air processor including a compressor operable in a cooling mode, in an ON cycle and an OFF cycle, and at a low compressor speed and a high compressor speed in response to said thermostat;

comprising, in combination;

sensor means for sensing actual relative humidity within said enclosure and providing a relative humidity signal;

selector means for selecting a desired relative humidity level within said enclosure and providing a set point signal;

compressor control means, coupled and responsive to said thermostat, said sensor means and said selector means, for overriding said first stage cooling demand signal and effecting said high compressor speed in a predetermined ON cycle of said compressor whenever actual relative humidity within said enclosure exceeds said desired relative humidity level;

humidifier control means, coupled and responsive to said sensor means and said selector means, for activating said humidifier whenever said actual relative humidity is below said desired relative humidity level; and

directive means for selectively enabling and disabling said compressor control means and said humidifier control means.

12. A control as claimed in claim 11 wherein said compressor control means overrides whenever said desired relative humidity level is exceeded during a compressor cycle prior to said predetermined ON cycle.

13. A control as claimed in claim 12 wherein said compressor control means establishes a humidity threshold above said desired relative humidity level in response to said set point signal, said compressor control means overriding said first stage cooling demand signal and effecting said high compressor speed during said ON cycle whenever said actual relative humidity exceeds said humidity threshold.

14. A control as claimed in claim 13 wherein said compressor control means includes:

adjustment means, coupled to said selector means, for receiving said set point signal and for responsively providing an adjusted signal corresponding to said relative humidity threshold;

first comparator means, coupled to said sensor means and said selector means, for receiving said relative humidity signal and said set point signal and for responsively providing a first comparator signal whenever actual relative humidity exceeds desired relative humidity level;

second comparator means, coupled to said sensor means and said adjustment means, for receiving said relative humidity signal and said adjusted signal and for responsively providing a second comparator signal whenever actual relative humidity exceeds said relative humidity threshold; and

override means, coupled to said thermostat, said first comparator means and said second comparator means, for receiving said first stage demand signal, said first comparator signal and said second comparator signal and for responsively effecting said high compressor speed.