DYNAMIC TEMPERATURE COMPENSATION OF A THERMOSTAT FOR AN EVAPORATIVE COOLER SYSTEM

• US 20200132554A1
• Filed: 10/30/2019
• Published: 04/30/2020
• Est. Priority Date: 10/30/2018
• Status: Active Grant

• Current Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Original Assignee: Ademco Inc. (Resideo Technologies, Inc.)
• Inventors: Aguilar, Rafael, Cano, Ricardo, Hernandez, Ever, Gonzalez, Ricardo
• Granted Patent: US 11,543,300 B2
• Time in Patent Office: Days
• CPC Class Codes: F24F 11/0001 for ventilation 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 11/70 Control systems characterised by their outputs; Constructional details thereof
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 5/0035 using evaporation
• CPC Class Codes: G01K 3/14 in respect of space
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature
• CPC Class Codes: G01K 7/427 Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation
• CPC Class Codes: G05D 23/1931 to control the temperature of one space
• CPC Class Codes: Y02B 30/54 Free-cooling systems

Abstract

The disclosure is directed to techniques for a thermostat to determine the air temperature of a room based on measurements of temperatures sensors located inside a housing of the thermostat. Because the thermostat for an evaporative cooler operates at line voltage and controls current flowing to the evaporative cooler, the magnitude of current flowing through the thermostat may vary from nearly zero, when the thermostat is in the powered-off state, to a current on the order of several amps. The variation in current causes a variation in temperature inside the housing of the thermostat. The techniques of this disclosure compensate for changes the internal housing temperature caused by changes in operating mode. The compensation allows the temperature sensors inside the thermostat housing to determine the air temperature of the room in which the thermostat is located, without regard for the operating mode of the evaporative cooler system.

Claims

1. A method comprising:

determining a temperature inside a housing at a first time based on a signal from a sensor, wherein the housing is a housing for a thermostat, and

determining an operating mode for the thermostat;

determining a charge level of a load controlled by the thermostat;

determining a dynamic factor based on;

the determined temperature inside the housing,

the operating mode, and

the charge level; and

applying the dynamic factor to the determined temperature inside the housing to determine an ambient temperature at the first time, wherein the ambient temperature is a temperature exterior to the housing.

2. The method of claim 1, wherein the load comprises a water pump.

3. The method of claim 1, wherein the load comprises a multi-speed motor.

4. The method of claim 3, wherein selecting the operating mode determines a speed for the multi-speed motor.

5. The method of claim 4, wherein the multi-speed motor is a two-speed motor.

6. The method of claim 4, further comprising:

determining the dynamic factor based on whether the operating mode changes from a first operating mode to a second operating mode, wherein a first current through the thermostat during the first operating mode is less than a second current through the thermostat during the second operating mode.

7. The method of claim 6, further comprising:

determining the dynamic factor based on whether the operating mode changes from the second operating mode to the first operating mode.

8. The method of claim 3, wherein the charge level is based on power consumption by the multi-speed motor during operation of the multi-speed motor.

9. The method of claim 8, wherein the sensor is a first sensor, the method further comprising:

determining the charge level based on a temperature difference between the first sensor and a second sensor.

10. The method of claim 1, further comprising:

determining a first value for the dynamic factor at a first time and determining a second value for the dynamic factor at a second time different from the first time, wherein;

during the second time the temperature inside the housing is at a steady state equilibrium temperature value for the operating mode, and

during the first time the temperature inside the housing is transitioning toward the steady state equilibrium temperature value for the operating mode.

11. A device comprising:

a housing;

a first temperature sensor located within the housing;

processing circuitry located within the housing and configured to;

receive signals from the first temperature sensor indicating a temperature within the housing;

receive an indication of an operating mode for the device;

determine a charge level of a load controlled by the device;

determine a dynamic factor based on;

the determined temperature inside the housing,

the operating mode, and

the charge level; and

apply the dynamic factor to the determined temperature inside the housing to determine an ambient temperature, wherein the ambient temperature is a temperature exterior to the housing.

12. The device of claim 11, wherein the load comprises a water pump.

13. The device of claim 11, wherein the load comprises a multi-speed motor.

14. The device of claim 13, wherein the operating mode selects a speed for the multi-speed motor.

15. The device of claim 14, wherein the processing circuitry is further configured to determine the dynamic factor based on whether the operating mode changes from a first operating mode to a second operating mode, wherein a first current through the device during the first operating mode is less than a second current through the device during the second operating mode.

16. The device of claim 15, wherein the processing circuitry is further configured to determine the dynamic factor based on whether the operating mode changes from the second operating mode to the first operating mode.

17. The device of claim 13, wherein the charge level is based on power consumption by the multi-speed motor during operation of the multi-speed motor.

18. The device of claim 11, wherein the processing circuitry is further configured to determine the charge level based on a temperature difference between the first temperature sensor and a second temperature sensor.

19. A system comprising:

an evaporative cooler device, comprising;

a water pump; and

a multi-speed blower motor; and

a thermostat device, the thermostat device comprising;

a housing;

a first temperature sensor located within the housing;

processing circuitry located within the housing and configured to;

receive signals from the first temperature sensor indicating a temperature within the housing;

receive an indication of an operating mode for the device, wherein the operating mode determines a speed setting for the multi-speed blower motor and determines an on-off setting for the water pump;

determine a charge level of a load controlled by the thermostat, wherein the load comprises the water pump and the blower motor;

determine a dynamic factor based on;

the determined temperature inside the housing,

the operating mode, and

the charge level; and

apply the dynamic factor to the determined temperature inside the housing to determine an ambient temperature, wherein the ambient temperature is a temperature exterior to the housing.

20. The system of claim 19, wherein the processing circuitry is further configured to determine the dynamic factor based on whether the operating mode changes from a first operating mode to a second operating mode, wherein a first current through the thermostat during the first operating mode is less than a second current through the thermostat during the second operating mode.