HVAC FILTER MONITORING

• US 20120125592A1
• Filed: 01/10/2011
• Published: 05/24/2012
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Nest Labs Incorporated (Alphabet Inc.)
• Inventors: FADELL, Anthony Michael, MATSUOKA, Yoky, ROGERS, Matthew Lee, SLOO, David
• Granted Patent: US 9,092,040 B2
• Time in Patent Office: Days
• US Class Current: 165/201
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• 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 11/32 Responding to malfunctions or emergencies
• CPC Class Codes: F24F 11/39 Monitoring filter performance
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/58 using Internet communication
• CPC Class Codes: F24F 11/61 using timers
• 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 11/63 Electronic processing
• CPC Class Codes: F24F 11/64 using pre-stored data
• CPC Class Codes: F24F 11/89 Arrangement or mounting of control or safety devices
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: F24F 2120/20 Feedback from users
• CPC Class Codes: F24F 2130/40 Noise
• CPC Class Codes: F24F 2140/00 Control inputs relating to system states
• CPC Class Codes: F24F 2140/60 : Energy consumption
• CPC Class Codes: G05B 13/0265 : the criterion being a learning criterion
• CPC Class Codes: G05B 15/02 : electric
• CPC Class Codes: G05D 23/19 : characterised by the use of electric means G05D23/1393 takes precedence
• CPC Class Codes: G05D 23/1902 : characterised by the use of a variable reference value
• CPC Class Codes: G05D 23/1917 : using digital means
• CPC Class Codes: H01R 9/2416 : Means for guiding or retaining wires or cables connected to terminal blocks
• CPC Class Codes: H04W 4/70 : Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: Y02B 10/20 : Solar thermal
• CPC Class Codes: Y02B 10/70 : Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02D 30/70 : in wireless communication networks
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

A method is described for identifying faults relating to an HVAC system, such a clogged filter. Sensor data is used to estimate HVAC system efficiency. Trends in system efficiency are then used to identify faults such as clogged filters. The sensor(s) can include one or more of the following types: optical sensor, temperature sensor, pressure sensor, acoustic transducer, humidity sensor, resistive sensor, capacitive sensor, and infrared sensor. The efficiency estimation can also be based on conditions external to the building, such as data from exterior sensors and/or data gathered from third parties such as government or private weather stations. The efficiency estimation can also be based on performance metrics such as the time used to reach a set point temperature. The fault identification includes filtering out non-fault related events.

An instrumented air filter for use with an HVAC system is also described. The air filter, which can be disposable, can also include one or more of the following: a wireless communication device adapted to transmit data from the sensor to a receiver; a power harvester (e.g. using piezoelectric elements) positioned and adapted to generate power from air passing through the filter; and a power storage device adapted to store power generated by the power harvester.

A method is also described for estimating HVAC system capacity based on user-inputted characteristics, such as the physical size, of an air filter used in the HVAC system.

Claims

1. A method for identifying conditions relating to an HVAC system fault comprising:

receiving sensor data representing readings from one or more sensors;

using a processing system to estimate HVAC system performance based at least in part on the received sensor data; and

identifying a condition relating to the HVAC system fault based at least in part on the estimated HVAC system performance.

2. A method according to claim 1 wherein the HVAC system performance is HVAC system efficiency.

3. A method according to claim 1 wherein the sensor data includes temperature data from a temperature sensor.

4. A method according to claim 3 wherein the method is carried out in a thermostat and the temperature sensor is within the thermostat.

5. A method according to claim 1 wherein the one or more sensors are of a type selected from a group consisting of:

optical sensor, temperature sensor, pressure sensor, acoustic transducer, humidity sensor, resistive sensor, capacitive sensor, and infrared sensor.

6. A method according to claim 1 wherein the HVAC system performance estimation is based in part on conditions external to a building being conditioned by the HVAC system.

7. A method according to claim 6 wherein the external conditions include data from one or more sensors located outside the building.

8. A method according to claim 6 wherein the external conditions include data gathered from a government agency.

9. A method according to claim 6 wherein the external conditions include data gathered from private weather stations.

10. A method according to claim 1 wherein the HVAC system performance estimation is based in part on building information gathered from an external database representing characteristics of a building being conditioned by the HVAC system.

11. A method according to claim 1 wherein the HVAC system performance estimation is based on a performance metric.

12. A method according to claim 11 wherein the performance metric includes time to reach a target temperature.

13. A method according to claim 1 wherein the condition identification includes filtering out non-fault related events.

14. A method according to claim 1 wherein the HVAC system fault is a clogged filter.

15. A method according to claim 1 wherein at least one of the one or more sensors is located within an air filter of the HVAC system.

16. A method according to claim 1 wherein the HVAC system is installed in building used primarily for residential or light-industrial purposes.

17. A method according to claim 1 wherein the condition is identified continuously such that slowly occurring changes can be identified.

18. A method according to claim 1 wherein the condition is displayed to a user.

19. A method according to claim 18 wherein the condition is HVAC filter condition.

20. A method according to claim 1 wherein a cost associates with the identified condition is displayed to a user.

21. A system for identifying conditions relating to an HVAC system fault comprising a processing system adapted and programmed to carry out a method according to claim 1.

22. An air filter for use with an HVAC system comprising:

a housing;

filtering media housed within the housing adapted to remove unwanted material from air passing through the HVAC system; and

a sensor housed within the housing.

23. A filter according to claim 22 wherein the air filter is disposable.

24. A filter according to claim 22 wherein the sensor is positioned and is of a type such that an estimate of filter condition can be made based at least in part on the sensor.

25. A filter according to claim 22 further comprising a wireless communication device housed within the housing adapted to transmit data from the sensor to a receiver.

26. A filter according to claim 22 further comprising a power harvester positioned and adapted to generate power from air passing through the filter.

27. A filter according to claim 26 wherein the power harvester includes one or more piezoelectric elements.

28. A filter according to claim 26 further comprising a power storage device adapted to store power generated by the power harvester.

29. A filter according to claim 22 wherein the sensor is of a type selected from a group consisting of:

optical sensor, temperature sensor, pressure sensor, acoustic transducer, humidity sensor, resistive sensor, capacitive sensor, and infrared sensor.

30. A filter according to claim 22 wherein the sensor is positioned and is of a type such that an HVAC system faults can be identified based at least in part on the sensor.

31. A filter according to claim 22 wherein the sensor is positioned and is of a type such that HVAC system modeling can be performed based at least in part on the sensor.

32. A filter according to claim 22 wherein the HVAC system is installed in building used primarily for residential or light-industrial purposes.

33. A method for estimating HVAC system capacity comprising:

receiving input from a user representing characteristics of an air filter used in the HVAC system; and

with a processing system, estimating HVAC system capacity based at least in part on the input received from the user.

34. A method according to claim 33 wherein the characteristics of the air filter include physical dimensions of the air filter.

35. A method according to claim 33 wherein the characteristics of the air filter include a manufacturer'"'"'s part number associated with the air filter.

36. A method according to claim 33 further comprising modeling characteristics of the HVAC system based in part on the estimated HVAC system capacity.

37. A thermostat for controlling an HVAC system having a processing system adapted and programmed to carry out the method according to claim 33.