Humidity control for multiple unit A/C system installations

• US 7,987,023 B2
• Filed: 02/18/2009
• Issued: 07/26/2011
• Est. Priority Date: 02/20/2008
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Liebert Corporation (Vertiv Holdings Co.)
• Inventors: Saunders, John E., Christensen, John F., Bush, Terry D.
• Primary Examiner(s): Masinick; Michael D
• Application Number:
  US12/388,224
• Publication Number:
  US 20090210095A1
• Time in Patent Office: 888 Days
• Field of Search: 700/276, 700/277, 621/761
• US Class Current: 700/277
• 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 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 3/14 by humidification; by dehumidification

Abstract

An air conditioning (A/C) system that may have a plurality of air conditioning units disposed in different zones of an area that each operate to cool the different zones, a humidity sensor for sensing the humidity in the area, and a controller. The controller may be adapted to analyze a sensible heat load being experienced by each of the air conditioning units and to control a latent heat removal being performed by each air conditioning unit such that a percentage of latent heat removal performed by each air conditioning unit does not exceed a percentage of sensible heat removal being performed by each air conditioning unit.

Claims

1. An air conditioning (A/C) system comprising:

a plurality of air conditioning units disposed in different zones of an open area that each operate to cool said different zones;

a humidity sensor for sensing the humidity in said area; and

a controller adapted to analyze a sensible heat load being experienced by each of said air conditioning units and to control a latent heat removal being performed by each said air conditioning unit such that a percentage of latent heat removal performed by each said air conditioning unit does not exceed a percentage of sensible heat removal being performed by each said air conditioning unit.

2. The system of claim 1, wherein said controller is adapted to reduce a latent heat removal load on least one of said air conditioning units while increasing a latent heat removal load on a different one of said air conditioning units.

3. The system of claim 1, wherein each said air conditioning unit is in communication with a temperature sensing system located in its associated said zone.

4. The system of claim 1, wherein said controller comprises a programmable controller.

5. The system of claim 1, wherein said controller is adapted to determine a distribution of additional latent cooling load between two different ones of said air conditioning units without exceeding said percentage of sensible heat removal being performed by said two different ones of said air conditioning units.

6. The system of claim 1, wherein said controller comprises a computer.

7. An air conditioning (A/C) system comprising:

a first air conditioning unit disposed in a first zone of an open area;

a second air conditioning unit disposed in a second zone of said open area, where the second zone is different from the first zone;

a first system for sensing temperature in said first zone;

a second system for sensing temperature in said second zone;

a humidity sensing system for sensing a humidity in said open area;

a controller for receiving information concerning a sensible heat load and a latent heat load being handled by each of said first and second air conditioning units, determining which one of said air conditioning units is able to accommodate additional latent heat removal without exceeding a percentage of sensible heat removal being performed by each said air conditioning unit, and controlling said one of said air conditioning units to provide a percentage of increased latent heat removal without causing a total percentage of latent heat removal loading on said one air conditioning unit to exceed said percentage of sensible heat removal being performed by said one air conditioning unit.

8. The system of claim 7, wherein said controller is adapted to reduce a latent heat removal load by one of said air conditioning units while increasing a latent heat removal load for the other one of said air conditioning units.

9. The system of claim 7, further comprising a third air conditioning unit, and where said controller is adapted to determine how said additional latent heat removal may be distributed between two of said first, second and third air conditioning units without causing a total latent heat removal load percentage being performed by said two air conditioning units to exceed said percentage of sensible heat removal being performed by each of said two air conditioning units.

10. The system of claim 7, wherein said controller comprises a programmable controller.

11. The system of claim 7, wherein said controller comprises a computer.

12. The system of claim 7, wherein said controller continuously monitors said sensible heat removal being performed by each of said air conditioning units and further adjusts a latent heat removal load for each said air conditioning unit in response to changes in a sensible heat load of any one of said air conditioning units.

13. An air conditioning (A/C) system comprising:

a first air conditioning unit disposed in a first zone of an open area;

a second air conditioning unit disposed in a second zone of said open area, where the second zone is different from the first zone;

a third air conditioning unit disposed in a third zone of open area, where the third zone is different from the first and second zones;

a first system for sensing temperature in said first zone;

a second system for sensing temperature in said second zone;

a third system for sensing temperature in said third zone;

a humidity sensing system for sensing a humidity in said open area;

a controller in communication with each of said first, second and third air conditioning units and adapted to monitor a sensible heat removal load and a latent heat removal load being experienced by each said air conditioning unit; and

said controller further adapted to determine which one or more of said air conditioning units is able to accommodate a portion of an additional latent heat removal load without having its percentage of total latent heat removal exceed a percentage of sensible heat removal being performed by each said air conditioning unit, and distributing said additional latent heat load to selected ones of said air conditioning units in accordance with available latent heat cooling capacity of selected ones of said air conditioning units.

14. The system of claim 13, wherein each of said first, second and third systems includes a humidity sensing capability.

15. The system of claim 13, wherein said controller comprises a programmable controller.

16. The system of claim 13, wherein said controller comprises a general purpose computer.

17. A method for controlling temperature and humidity in an open area having a plurality of zones, the method comprising:

disposing an air conditioning unit in each of said zones;

sensing a temperature in each of said zones;

sensing a humidity in said area;

determining a sensible heat removal load being experienced by each said air conditioning unit; and

balancing a removal of latent heat within said area by said air conditioning units such that a percentage of latent heat removal load being experienced by each said air conditioning unit does not exceed a percentage of its said sensible heat removal load.

18. The method of claim 17, wherein said balancing a removal of latent heat within said area comprises limiting a percentage of latent heat removal load being experienced by a selected one or more of said air conditioning units.

19. The method of claim 17, wherein said balancing a removal of latent heat within said area by said air conditioning units comprises reducing a percentage of latent heat removal being performed by one of said air conditioning units and increasing a percentage of latent heat removal by a different one of said air conditioning units.

20. The method of claim 17, wherein balancing a removal of latent heat within said area by said air conditioning units comprises using a controller to communicate with said air conditioning units and to control said percentage of latent heat removal being experienced by each of said air conditioning units.

21. The method of claim 17, wherein balancing a removal of latent heat within said area by said air conditioning units comprises a communications bus to communicate with a processor/communications subsystem of each said air conditioning unit, such that said processor/communications subsystems may cooperatively control their said percentages of latent heat removal.