REMOTE CONTROL OF AN HVAC SYSTEM THAT USES A COMMON TEMPERATURE SETPOINT FOR BOTH HEAT AND COOL MODES

• US 20120067561A1
• Filed: 09/21/2010
• Published: 03/22/2012
• Est. Priority Date: 09/21/2010
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Bergman, Gabriel Albert, Mullarkey, Chris, Leen, Cary, Schultz, David, Cabel, Milos
• Granted Patent: US 8,950,687 B2
• Time in Patent Office: Days
• US Class Current: 165/257
• CPC Class Codes: B60H 1/00657 Remote control devices
• CPC Class Codes: B60H 2001/00733 Computational models modifying user-set values
• 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 11/56 Remote control
• CPC Class Codes: F24F 11/59 for presetting
• CPC Class Codes: F24F 11/65 for selecting an operating mode
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: G05D 23/1904 variable in time
• CPC Class Codes: G05D 23/1905 associated with tele control

Abstract

An HVAC system includes an HVAC unit having a cooling mode and a heating mode for conditioning the air in an inside space, and a programmable thermostat located remotely from the HVAC unit. The HVAC unit may have an onboard controller configured to control when the HVAC unit is in the cooling mode or heating mode, and whether the HVAC unit is activated or not. In some cases, the onboard controller of the HVAC unit may use a common temperature setpoint when controlling in the cooling mode and the heating mode. The programmable thermostat may have a programmable schedule with a plurality of time periods, where each time period has a heating setpoint and a cooling setpoint separated by a dead band. The onboard controller of the HVAC unit may be configured to accept input signals from the remotely located thermostat. The remotely located thermostat may send one or more input signals to the onboard controller of the HVAC unit in accordance with the programmable schedule, where the one or more input signals cause the onboard controller of the HVAC unit to set the HVAC unit to a particular one of the cooling mode and the heating mode, and to activate the HVAC unit so as to condition the air in the inside space in the particular one of the cooling mode and the heating mode.

Claims

1. An HVAC system for conditioning the air of an inside space, comprising:

an HVAC unit having a cooling mode and a heating mode for conditioning the air in the inside space, the HVAC unit having an onboard controller that is configured to control whether the HVAC unit is in the cooling mode or heating mode, and whether the HVAC unit is activated or not, the onboard controller of the HVAC unit using a common temperature setpoint regardless of whether in the cooling mode or the heating mode; and

a programmable thermostat located remotely from the HVAC unit, the programmable thermostat having a programmable schedule with a plurality of time periods, where each time period has a heating setpoint and a cooling setpoint separated by a dead band;

wherein the onboard controller of the HVAC unit is configured to accept input signals from the remotely located thermostat; and

wherein the remotely located thermostat has an auto changeover mode, wherein in the auto changeover mode, the remotely located thermostat sends one or more input signals to the onboard controller of the HVAC unit in accordance with the programmable schedule, the one or more input signals causing the onboard controller of the HVAC unit to set the HVAC unit to a particular one of the cooling mode and the heating mode, and to activate the HVAC unit so as to condition the air in the inside space in the particular one of the cooling mode and the heating mode.

2. The HVAC system of claim 1, wherein, in the auto changeover mode, the thermostat communicates a control setpoint to the onboard controller of the HVAC system, wherein the onboard controller uses the received control setpoint as the common temperature setpoint.

3. The HVAC system of claim 2, wherein the control setpoint is an artificial control setpoint that causes the onboard controller of the HVAC unit to set the HVAC unit to a particular one of the cooling mode and the heating mode, and to activate the HVAC unit so as to condition the air in the inside space in the particular one of the cooling mode and the heating mode.

4. The HVAC system of claim 3, wherein, in the auto changeover mode, the thermostat sends one or more input signals that cause the onboard controller of the HVAC unit to deactivate.

5. The HVAC system of claim 1, wherein the HVAC system is a mini-split HVAC system.

6. The HVAC system of claim 1, wherein the remotely located thermostat transmits input signals to the onboard controller of the HVAC unit wirelessly.

7. The HVAC system of claim 6 further comprising an equipment interface module communicatively coupled to the onboard controller of the HVAC unit, the equipment interface module configured to receive wireless signals from the remotely located thermostat and communicate input signals to the onboard controller of the HVAC unit corresponding to the wireless signals received from the remotely located thermostat.

8. A method for controlling a mini-split system HVAC unit via a thermostat that is located remotely from the HVAC unit, the HVAC unit having a cooling mode and a heating mode for conditioning air in the inside space, the HVAC unit having an onboard controller that is configured to control whether the HVAC unit is in the cooling mode or heating mode, and whether the HVAC unit is activated or not, the onboard controller of the HVAC unit is configured to accept input signals wirelessly transmitted from the remotely located thermostat, the method comprising:

the remotely located thermostat comparing a sensed temperature in the inside space with a setpoint, and determining if the sensed temperature is different from the setpoint by at least a predetermined amount; and

if the sensed temperature is different from the setpoint by at least the predetermined amount, the thermostat wirelessly sending one or more input signals to the onboard controller of the HVAC unit, the one or more input signals causing the onboard controller of the HVAC unit to set the HVAC unit to a particular one of the cooling mode and the heating mode, and to activate the HVAC unit so as to condition the air in the inside space in the particular one of the cooling mode and the heating mode in accordance with a control setpoint.

9. The method of claim 8, wherein the HVAC unit includes a temperature sensor that provides a measure related to the air temperature local to the HVAC unit, and the onboard controller of the HVAC unit controls the measure related to the air temperature local to the HVAC unit to the control setpoint while the HVAC system is in the particular one of the cooling mode and the heating mode.

10. The method of claim 8, wherein the thermostat communicates a measure related to the air temperature in the inside space to the onboard controller of the HVAC system, wherein the onboard controller controls the measure related to the air temperature in the inside space to the control setpoint while the HVAC system is in the particular one of the cooling mode and the heating mode.

11. The method of claim 8, wherein after the HVAC unit is activated, and if the sensed temperature in the inside space becomes not different from the setpoint by at least the predetermined amount, the thermostat sends one or more input signals to the onboard controller of the HVAC unit that cause the onboard controller to deactivate the HVAC unit.

12. The method of claim 8, wherein the thermostat wirelessly communicates the control setpoint to the onboard controller of the HVAC system, wherein the onboard controller controls to the control setpoint while the HVAC system is in the particular one of the cooling mode and the heating mode.

13. The method of claim 12, wherein the control setpoint is an artificial control setpoint that causes the onboard controller of the HVAC unit to set the HVAC unit to a particular one of the cooling mode and the heating mode, and to activate the HVAC unit so as to condition the air in the inside space in the particular one of the cooling mode and the heating mode.

14. The method of claim 8, further comprising maintaining in a memory of the thermostat a schedule having a plurality of time periods, each time period having one or more time period setpoints, wherein, in the comparing step, the sensed temperature in the inside space is compared with a corresponding one of the one or more time period setpoints of the schedule.

15. The method of claim 14, wherein at least one of the plurality of time periods includes a heating setpoint and a cooling setpoint, wherein the thermostat is configured to select between the heating setpoint and the cooling setpoint for the at least one time period for use in the comparing step when in an auto changeover mode.

16. The method of claim 15, wherein:

if the sensed temperature in the inside space is higher than the cooling setpoint, the thermostat wirelessly sends one or more input signals that cause the onboard controller of the HVAC unit to set the HVAC unit to the cooling mode and activate the HVAC unit; and

if the sensed temperature in the inside space is lower than the heating setpoint, the thermostat wirelessly sends one or more input signals that cause the onboard controller of the HVAC unit to set the HVAC unit to the heating mode and activate the HVAC unit.

17. A wireless HVAC control system configured to command an HVAC unit, the HVAC unit having a heating mode and a cooling mode for modifying an air temperature of an inside space, the HVAC unit having an onboard HVAC unit thermostatic controller, the onboard HVAC unit thermostatic controller configured to accept external selection of a control mode including a cooling control mode and a heating control mode, external input of an onboard setpoint, and external override of a current control temperature, the wireless HVAC control system including a wireless thermostat, the wireless thermostat comprising:

a memory for storing operational parameters of the wireless thermostat including setpoints that include at least a cooling setpoint and a heating setpoint;

a user interface configured to allow a user to modify the operational parameters of the wireless thermostat;

a transmitter configured to transmit commands wirelessly to the HVAC unit;

a temperature sensor disposed to measure the air temperature; and

a controller operatively coupled to the memory, the user interface, the transmitter and the temperature sensor;

wherein the controller is programmed to;

determine whether modification of the air temperature is desired by comparing the air temperature measured by the temperature sensor with at least one of the cooling setpoint and the heating setpoint;

if modification of the air temperature is not desired, wirelessly commanding the onboard HVAC unit thermostatic controller, via the transmitter, to prevent modification of the air temperature by the HVAC unit; and

if modification of the air temperature is desired, wirelessly commanding via the transmitter to the onboard HVAC unit thermostatic controller to;

externally select the control mode; and

externally input the onboard setpoint and/or externally override the current control temperature with values effective to cause the HVAC unit to cool or heat, according to the desire for modification of the air temperature.

18. The wireless HVAC control system of claim 17, further comprising a equipment interface module configured to communicatively couple to a control port of the HVAC unit, the equipment interface module including a receiver configured to receive wireless commands from the transmitter of the wireless thermostat, the equipment interface module configured to communicate commands to the HVAC unit via the control port, wherein the commands communicated to the HVAC unit via the control port are based upon the wireless commands from the transmitter of the wireless thermostat.

19. The wireless HVAC control system of claim 17,

wherein the operational parameters stored in the memory of the wireless thermostat include a schedule having a plurality of time periods, at least one of the plurality of time periods associated with a time period cooling setpoint and a time period heating setpoint;

and

wherein, in the determining step the controller is programmed to perform, the step of comparing the air temperature measured by the temperature sensor with at least one of the cooling setpoint and the heating setpoint includes comparing the air temperature with the time period cooling setpoint and the time period heating setpoint during the at least one of the plurality of time periods, such that;

if the air temperature is higher than the time period cooling setpoint, it is determined that cooling is desired;

if the air temperature is lower than the time period heating setpoint, it is determined that heating is desired; and

if the air temperature is between the time period cooling setpoint and the time period heating setpoint, it is determined that modification of the air temperature is not desired.

20. The wireless HVAC control system of claim 17, wherein the HVAC unit is a mini-split system.