Thermostat and method for controlling an HVAC system with remote temperature sensor and onboard temperature sensor

Patent metadata

Field	Value
Publication number	US-10684037-B2
Application number	US-201715724895-A
Country	US
Kind code	B2
Filing date	Oct 4, 2017
Priority date	Oct 4, 2017
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A heating, ventilation and air condition (HVAC) system is provided. The system includes a thermostat including an onboard temperature sensor, a remote temperature sensor in operable communication with the thermostat, and a controller in operable communication with each of the onboard sensor and the remote sensor and configured to execute a control algorithm that calculates a temperature difference between a temperature detected by the onboard temperature sensor and a temperature detected by the remote temperature sensor, such that when the remote temperature sensor fails, the controller uses the calculated temperature difference to calibrate the onboard temperature sensor and set the thermostat to the temperature detected by the remote temperature sensor.

First claim

What is claimed is:

1. A heating, ventilation and air condition (HVAC) system, the system comprising:
a thermostat including an onboard temperature sensor;
a remote temperature sensor in operable communication with the thermostat; and
a controller in operable communication with each of the onboard temperature sensor and the remote temperature sensor and configured to execute a control algorithm that calculates a temperature difference between a temperature detected by the onboard temperature sensor and a temperature detected by the remote temperature sensor, such that when the remote temperature sensor fails, the controller uses the calculated temperature difference to calibrate the onboard temperature sensor.

2. The system of claim 1 , wherein the control algorithm is configured to calculate the temperature difference by mapping a temperature detected by the remote temperature sensor to a temperature detected by the onboard temperature sensor over a time period, calculate an error constant based on the mapped temperatures, and calibrate the onboard temperature sensor.

3. The system of claim 2 , wherein the time period is divided into a plurality of time periods and the error constant is calculated for each time period of the plurality of time periods.

4. The system of claim 3 , wherein the control algorithm is further configured to analyze a pattern of the error constant over one time period of the plurality of time periods, if the pattern of the error constant deviates beyond a predetermined threshold pattern for a predetermined time, alert a user, via the thermostat, of the deviation, and calibrate the onboard temperature sensor.

5. The system of claim 2 , wherein the control algorithm calculates the error constant using the equations:

Δ
⁢

⁢

T
⁡

[
n
]

=

onboardtemperaturesensor
⁡

[
n
]

-

remotetemperaturesensor
⁡

[
n
]

(
1
)

α
=

exp
(

-
1

t
*
fs

)

(
2
)

errorconstant
⁡

[
n
]

=

α
⁢

⁢

errorconstant
⁡

[

n
-
1

]

+

(

1
-
α

)

⁢
Δ
⁢

⁢

T
⁡

[
n
]

,

(
3
)

wherein t is a defined time constant or interval and fs is a defined sample rate.

6. The system of claim 1 , wherein the remote temperature sensor is connected to the thermostat via a wireless connection or a wired connection.

7. The system of claim 1 , wherein the onboard temperature sensor is configured as a backup sensor, and
wherein the remote temperature sensor is configured as a primary sensor.

8. A method for controlling a heating, ventilation and air condition (HVAC) system having a thermostat coupled to a remote temperature sensor and an onboard temperature sensor, the method comprising:
executing, using a controller, a control algorithm that calculates a temperature difference between a temperature detected by the onboard temperature sensor and a temperature detected by the remote temperature sensor; and
when the remote temperature sensor fails, using the calculated temperature difference to calibrate the onboard temperature sensor.

9. The method of claim 8 , further comprising calculating the temperature difference by mapping a temperature detected by the remote temperature sensor to a temperature detected by the onboard temperature sensor over a time period, calculating an error constant based on the mapped temperatures, and calibrating the onboard temperature sensor.

10. The method of claim 9 , further comprising dividing the time period into a plurality of time periods and calculating the error constant for each time period of the plurality of time periods.

11. The method of claim 10 , further comprising analyzing a pattern of the error constant over one time period of the plurality of time periods, if the pattern of the er

Assignees

• Trane Int Inc

Inventors

• Kaliyaperumal Arulkumar
• Smith Christopher Blake
• Hughes John
• Vairamudi Vinoth
• Thiruvengadam Satish Mukundan
• Kraft Wayne N

Classifications

• F24F11/32

  Responding to malfunctions or emergencies · CPC title

• F24F11/61

  using timers · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title

• G05B19/042

  using digital processors (G05B19/05 takes precedence) · CPC title

• F24F11/38

  Failure diagnosis · CPC title