Control for a heating ventilating and air conditioning unit

• US 6,491,094 B2
• Filed: 02/06/2001
• Issued: 12/10/2002
• Est. Priority Date: 05/04/1999
• Status: Expired due to Fees

• Current Assignee: York International Corporation (Johnson Controls International plc)
• Original Assignee: York International Corporation (Johnson Controls International plc)
• Inventors: Rayburn, Ronald R., Hughes, Neil A.
• Primary Examiner(s): CIRIC, LJILJANA V
• Application Number:
  US09/776,884
• Publication Number:
  US 20010010266A1
• Time in Patent Office: 672 Days
• Field of Search: 165/248, 165/217, 165/249, 165/250, 165/251, 165/207, 165/208, 165/205, 236/49.3, 454/256, 454/258
• US Class Current: 165/250
• 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 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/76 by means responsive to temperature, e.g. bimetal springs
• CPC Class Codes: F24F 11/81 by controlling the air supply to heat-exchangers or bypass channels
• 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 2110/10 Temperature
• CPC Class Codes: F24F 2110/12 of the outside air
• CPC Class Codes: F24F 3/044 Systems in which all treatment is given in the central station, i.e. all-air systems

Abstract

A control system for a heating, ventilating, and air conditioning unit having a heating stage, a cooling stage, and an economizer is provided. The system includes a memory configured to store a first predetermined temperature range and a second predetermined temperature range. The system also includes a control having an input device configured to receive an indoor air temperature representative of the air in one or more zones and a supply air temperature representative of the air entering the one or more zones. The control selectively activates at least one of the heating stage, the cooling stage, and the economizer when the indoor air temperature is outside of the first predetermined temperature range. The control also selectively activates at least one of the heating stage, the cooling stage, and the economizer when the indoor air temperature is within the first predetermined temperature range and the sensed temperature of the supply air is outside of the second predetermined temperature range.

Claims

1. A control system for a heating, ventilating, and air conditioning unit having a heating stage, a cooling stage, and an economizer configured to provide outdoor air to the conditioning unit, the control system comprising:

a memory means for storing a first predetermined temperature range and a second predetermined temperature range; and

a control means for receiving an indoor air temperature representative of the air in one or more zones and a supply air temperature representative of the air entering the one or more zones, the control means selectively operating the conditioning unit in a conditioning mode by activating at least one of the heating stage, the cooling stage, and the economizer when the indoor air temperature is outside of the first predetermined temperature range, the control means selectively operating the conditioning unit in a ventilation mode when the indoor air temperature is within the first predetermined temperature range, and the control means selectively activating at least one of the heating stage, the cooling stage, and the economizer when the conditioning unit is operating in the ventilation mode and the sensed temperature of the supply air is outside of the second predetermined temperature range.

2. The system of claim 1, further comprising one or more thermostats, one of said thermostats disposed in each of the one or more zones.

3. The system of claim 2, wherein each thermostat is programmable and configured to receive an upper setpoint and a lower setpoint for the first predetermined temperature range.

4. The system of claim 3, wherein the control means activates the heating stage when the conditioning unit is operating in the ventilation mode and the supply air temperature is below the second predetermined temperature range.

5. The system of claim 3, wherein the control means activates the cooling stage when the conditioning unit is operating in the ventilation mode and the supply air temperature is above the second predetermined temperature range.

6. The system of claim 3, wherein each thermostat is configured to receive an upper setpoint and a lower setpoint for the second predetermined temperature range.

7. The system of claim 6, wherein the control means receives an outdoor air temperature representative of the outdoor air.

8. The system of claim 7, wherein the control means selectively modulates the economizer to increase the amount of outdoor air supplied to the conditioning unit when the conditioning unit is operating in the ventilation mode, the supply air temperature is above the upper setpoint of the second predetermined temperature range, and the outdoor air is below the upper setpoint of the second predetermined temperature range.

9. The system of claim 7, wherein the control means selectively modulates the economizer to increase the amount of outdoor air supplied to the conditioning unit when the conditioning unit is operating in the ventilation mode, the supply air temperature is below the lower setpoint of the second predetermined temperature range, and the outdoor air is above the lower setpoint of the second predetermined temperature range.

10. A control system for a conditioning unit having a heating stage and an economizer configured to provide outdoor air to the conditioning unit, the control system comprising:

a memory means for storing a first predetermined temperature range having an upper setpoint and a lower setpoint and a second predetermined temperature range having an upper setpoint and a lower setpoint; and

a control means for receiving an indoor air temperature representative of the air in one or more zones, a supply air temperature representative of the air entering the one or more zones, and an outdoor temperature representative of the outdoor air, the control means selectively modulating the economizer to increase the amount of outdoor air entering the conditioning unit when the indoor air temperature is within the first predetermined temperature range, the supply air temperature is above the upper setpoint of the second predetermined temperature range, and the outdoor air temperature is below the upper setpoint of the second predetermined temperature range.

11. The system of claim 10, wherein the control means activates the heating stage when the temperature of the indoor air is within the first predetermined temperature range and the supply air temperature is below the second predetermined temperature range.

12. The system of claim 10, further comprising one or more thermostats, one of said thermostats disposed in each of the one or more zones.

13. The system of claim 12, wherein each thermostat is programmable and configured to receive the upper setpoint and the lower setpoint for the first predetermined temperature range and the upper setpoint and the lower setpoint for the second predetermined temperature range.

14. A control system for a conditioning unit having a cooling stage and an economizer configured to provide outdoor air to the conditioning unit, the control system comprising:

a memory for storing a first predetermined temperature range having an upper setpoint and a lower setpoint and a second predetermined temperature range having an upper setpoint and a lower setpoint; and

a control means for receiving an indoor air temperature representative of the air in one or more zones, a supply air temperature representative of the air entering the one or more zones, and an outdoor temperature representative of the outdoor air, the control means selectively modulating the economizer when the indoor air temperature is within the first predetermined temperature range, the supply air temperature is below the lower setpoint of the second predetermined temperature range and the outdoor air temperature is above the lower setpoint of the second predetermined temperature range.

15. The system of claim 14, wherein the control means activates the cooling stage when the temperature of the indoor air is within the first predetermined temperature range and the supply air temperature is below the second predetermined temperature range.

16. The system of claim 14, further comprising one or more thermostats, one of said thermostats disposed in each of the one or more zones.

17. The system of claim 16, wherein each thermostat is programmable and is configured to receive the upper setpoint and the lower setpoint for the first predetermined temperature range and the upper setpoint and the lower setpoint for the second predetermined temperature range.