1:19-cv-12322
EcoFactor Inc v. Google Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:- Plaintiff: EcoFactor, Inc. (Palo Alto, California)
- Defendant: Google LLC (Delaware)
- Plaintiff’s Counsel: Birnbaum & Godkin, LLP
 
- Case Identification: 1:19-cv-12322, D. Mass., 11/12/2019
- Venue Allegations: Plaintiff alleges venue is proper in the District of Massachusetts because Defendant has transacted business, committed acts of infringement, and maintains at least one regular and established place of business in the district.
- Core Dispute: Plaintiff alleges that Defendant’s Nest Learning Thermostat and related smart thermostat products infringe four patents related to automated HVAC efficiency analysis, thermal modeling, just-in-time conditioning, and adaptive programming.
- Technical Context: The lawsuit concerns the field of smart home energy management, where networked thermostats use data analytics to optimize HVAC operation for energy savings and user comfort.
- Key Procedural History: The complaint alleges that Defendant had pre-suit knowledge of all four asserted patents based on a prior complaint Plaintiff filed in the International Trade Commission (ITC) and because Defendant allegedly cited the patents during the prosecution of its own patent applications.
Case Timeline
| Date | Event | 
|---|---|
| 2007-09-17 | ’497 and ’322 Patents Priority Date | 
| 2009-05-08 | ’753 Patent Priority Date | 
| 2009-05-12 | ’371 Patent Priority Date | 
| 2012-03-06 | ’497 Patent Issue Date | 
| 2013-04-16 | ’322 Patent Issue Date | 
| 2013-07-30 | ’753 Patent Issue Date | 
| 2018-07-10 | ’371 Patent Issue Date | 
| 2019-10-21 | Alleged Pre-Suit Knowledge via ITC Complaint | 
| 2019-11-12 | Complaint Filing Date | 
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,423,322 - "System and method for evaluating changes in the efficiency of an HVAC system," issued April 16, 2013
The Invention Explained
- Problem Addressed: The patent describes the problem that conventional thermostats cannot account for suboptimal installations (e.g., placement in direct sunlight) or detect degradation in HVAC system performance over time, which can lead to erroneous temperature readings, user discomfort, and wasted energy (’322 Patent, col. 2:30-51).
- The Patented Solution: The invention is a networked system that evaluates HVAC efficiency by collecting data from a thermostat (e.g., inside temperature, system status) and external sources (e.g., outside temperature) over time. By comparing a system's current performance against its own historical data and against the performance of other HVAC systems in a database, the system can identify and diagnose decreases in operational efficiency, such as those caused by a clogged filter or refrigerant leak (’322 Patent, Abstract; Fig. 12).
- Technical Importance: This technology enables proactive diagnostics and maintenance by identifying drops in HVAC efficiency that would otherwise be difficult for a homeowner to detect (’322 Patent, col. 4:32-44).
Key Claims at a Glance
- The complaint asserts independent claim 1 and refers to an associated claim chart exhibit, which was not provided with the complaint (Compl. ¶13).
- Essential elements of independent claim 1 include:- An HVAC control system in a first structure that receives temperature measurements and HVAC status.
- One or more processors that receive outside temperature data and compare the inside and outside temperatures over time.
- One or more databases that store the temperature measurements from the first structure.
- The processors compare an inside temperature at one time with an inside temperature at a different time to determine if the HVAC system's operational efficiency has decreased.
 
- The complaint alleges infringement of "one or more claims" of the patent, reserving the right to assert additional claims (Compl. ¶11).
U.S. Patent No. 8,131,497 - "System and method for calculating the thermal mass of a building," issued March 6, 2012
The Invention Explained
- Problem Addressed: The patent notes that a building's "thermal mass"—its ability to resist temperature changes—significantly affects the efficiency of heating and cooling, but conventional thermostats have no mechanism to account for it. This makes it difficult to optimize pre-conditioning strategies, as a high-thermal-mass structure will respond differently than a low-thermal-mass one (’497 Patent, col. 3:1-14).
- The Patented Solution: The invention is a system that calculates a building's effective thermal mass by using one or more processors to analyze the rate of change in inside temperature relative to outside temperature and HVAC system status ("on" or "off"). This thermal model allows the system to optimize control strategies, such as pre-cooling a high-thermal-mass house just before peak electricity rates begin, thereby shifting energy consumption to lower-cost periods without sacrificing comfort (’497 Patent, Abstract; col. 3:15-33).
- Technical Importance: The technology allows for HVAC scheduling that is tailored to the specific thermal properties of an individual building, enabling more sophisticated energy optimization strategies.
Key Claims at a Glance
- The complaint asserts independent claims 1 and 7 and refers to an associated claim chart exhibit, which was not provided with the complaint (Compl. ¶22).
- Essential elements of independent claim 1 include:- An HVAC control system receiving temperature measurements from a location.
- Databases for storing said temperature measurements over time.
- Processors that receive outside temperature data and are configured to calculate rates of change in the inside temperature during periods when the HVAC system is "on" and during periods when it is "off".
- The processors relate the calculated rates of change to the outside temperature measurements.
 
- The complaint alleges infringement of "one or more claims," reserving the right to assert others (Compl. ¶20).
U.S. Patent No. 8,498,753 - "System, method and apparatus for just-in-time conditioning using a thermostat," issued July 30, 2013
- Technology Synopsis: This patent addresses the efficient pre-conditioning of a space to meet a target temperature at a future target time. The system calculates the ideal time to start the HVAC system by using a thermal model of the structure and the HVAC system's performance characteristics, thereby avoiding the energy waste of starting too early or the discomfort of starting too late (’753 Patent, Abstract).
- Asserted Claims: The complaint references a claim chart for independent claims 1, 9, and 15 (Compl. ¶31).
- Accused Features: The complaint alleges that the Nest Learning Thermostat's features for scheduling and achieving target temperatures infringe the ’753 Patent (Compl. ¶29).
U.S. Patent No. 10,018,371 - "System, method and apparatus for identifying manual inputs to and adaptive programming of a thermostat," issued July 10, 2018
- Technology Synopsis: This patent addresses how a smart thermostat interprets and adapts to a user's manual overrides of a pre-set schedule. The system detects a manual change, compares it to historical override data and contextual information, and applies rules to determine whether to treat the change as a temporary adjustment or as a signal to permanently update the long-term program (’371 Patent, Abstract).
- Asserted Claims: The complaint references a claim chart for independent claims 1, 9, and 17 (Compl. ¶40).
- Accused Features: The complaint alleges that the "adaptive programming" or "learning" capabilities of the Nest Learning Thermostat, which adjust schedules based on user inputs, infringe the ’371 Patent (Compl. ¶38).
III. The Accused Instrumentality
Product Identification
The complaint identifies "certain smart thermostat products ('Accused Products'), such as the Nest Learning Thermostat" (Compl. ¶11).
Functionality and Market Context
- The complaint alleges the Accused Products are part of "smart home energy management services" that employ "big-data analytics and machine learning algorithms" to process residential data (thermodynamics, comfort preferences) and external data (weather) (Compl. ¶2). The stated goal is to "continually monitor, adapt and learn for optimum energy savings" by actively managing thermostats on the user's behalf (Compl. ¶2-3).
- The allegations position the Accused Products in the market for advanced, automated home energy management, a field in which Plaintiff claims to be a recognized innovator (Compl. ¶4).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint alleges infringement and states that detailed claim charts are attached as exhibits; these exhibits were not filed with the complaint. The analysis below is based on the infringement theories implied by the complaint's narrative allegations and the language of the asserted independent claims.
8,423,322 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation | 
|---|---|---|---|
| at least one HVAC control system associated with a first structure that receives temperature measurements... and receives status of said HVAC system; | The Nest Learning Thermostat allegedly measures indoor temperature and monitors the operational status (on/off cycles) of the connected HVAC system. | ¶11 | col. 14:14-19 | 
| one or more processors that receive measurements of outside temperatures from at least one source other than said HVAC system... | The Accused Products allegedly connect to remote servers that obtain weather data and process it in conjunction with data from the thermostat. | ¶11, ¶2 | col. 14:20-22 | 
| ...and compare said temperature measurements from said first structure, wherein said one or more processors compares the inside temperature of said first structure and the outside temperature over time; | The Nest system's "big-data analytics and machine learning algorithms" are alleged to compare indoor temperature, outdoor temperature, and HVAC performance over time. | ¶13, ¶2 | col. 14:22-25 | 
| wherein said one or more processors compares an inside temperature recorded inside the first structure with an inside temperature... recorded at a different time to determine whether the operational efficiency of the HVAC system has decreased over time. | The Nest system's adaptive and learning features are alleged to compare current HVAC performance with historical performance to identify changes in how the system operates, which is alleged to constitute determining a decrease in efficiency. | ¶13, ¶2 | col. 14:41-47 | 
Identified Points of Contention
- Scope Question: A primary issue may be whether the Accused Products' alleged use of "machine learning algorithms" (Compl. ¶2) to "adapt and learn" performs the specific comparison recited in claim 1: comparing inside temperatures at different times "to determine whether the operational efficiency... has decreased."
- Technical Question: What evidence does the complaint provide that the Nest system's general adaptive functionality meets the specific claim requirement of evaluating "operational efficiency"? The analysis may turn on whether the accused system performs a targeted efficiency calculation or a more general performance optimization.
8,131,497 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation | 
|---|---|---|---|
| at least one HVAC control system that receives temperature measurements from at least a first location... | The Nest Learning Thermostat is alleged to measure the temperature at its location within a home. | ¶20 | col. 13:31-34 | 
| one or more processors that receive outside temperature measurements... | The Accused Products allegedly use remote servers to obtain external weather data for use in their control algorithms. | ¶22, ¶2 | col. 13:40-43 | 
| ...configured to calculate one or more rates of change in temperature at said first location for periods during which the status of the HVAC system is “on” and... “off”... | The Nest system's analytics are alleged to model how a home's temperature changes over time, both while the HVAC is running and while it is not, to understand the building's thermal properties. | ¶22, ¶2 | col. 13:43-52 | 
| ...and to relate said calculated rates of change to said outside temperature measurements. | The Nest system's algorithms allegedly correlate the observed indoor temperature changes with the corresponding outdoor weather conditions to build a thermal model of the home. | ¶22, ¶2 | col. 13:52-54 | 
Identified Points of Contention
- Scope Question: Does the Nest system's general "learning" about a home's thermal characteristics constitute "calculating one or more rates of change" as required by the claim? The dispute may focus on whether a specific mathematical calculation of a rate is performed versus a more abstract, model-based learning process.
- Technical Question: What evidence demonstrates that the Accused Products separately calculate rates of change for "on" periods and "off" periods and relate them to outside temperatures, as opposed to using a unified model that implicitly accounts for these factors?
V. Key Claim Terms for Construction
Term from the ’322 Patent: "operational efficiency"
- Context and Importance: This term is the central subject of claim 1. Its definition is critical because the infringement analysis will depend on whether the Accused Products are found to determine a "decrease" in this specific metric. Practitioners may focus on this term because its potential ambiguity could be a key point of non-infringement or invalidity arguments.
- Intrinsic Evidence for Interpretation:- Evidence for a Broader Interpretation: The specification suggests "efficiency" relates to diagnosing a wide range of "problems and malfunctions" and "anomalous behavior," which could support a broad definition covering any degradation in performance (’322 Patent, col. 4:32-44; col. 10:13-16).
- Evidence for a Narrower Interpretation: The specification provides specific examples of what causes decreased efficiency, such as "clogged filters, refrigerant leaks, duct leakage," each with a distinct performance "signature." A defendant could argue the term is limited to the calculation of these specific types of measurable degradations (’322 Patent, col. 11:4-6; col. 12:5-12).
 
Term from the ’497 Patent: "calculating... rates of change in temperature"
- Context and Importance: This term defines the core action for determining a building's thermal characteristics. The case may turn on whether the Accused Products' method of modeling a home's thermal response meets this definition.
- Intrinsic Evidence for Interpretation:- Evidence for a Broader Interpretation: The claim language is general, not specifying a particular mathematical formula. The specification describes the concept at a high level by showing graphs of inside temperature following outside temperature, which could support any method that determines this relationship (’497 Patent, Fig. 6A).
- Evidence for a Narrower Interpretation: The specification describes a system that "logs the temperature readings from inside each house (whether once per minute or over some other interval)" and compares them. A defendant may argue this implies a specific process of discrete data logging and slope calculation, rather than a holistic machine-learning approach (’497 Patent, col. 8:31-34).
 
VI. Other Allegations
Indirect Infringement
The complaint alleges that Defendant induces infringement of all asserted patents by providing "user manuals and online instruction materials" that actively encourage and instruct customers to use the Accused Products in ways that directly infringe (Compl. ¶12, ¶21, ¶30, ¶39).
Willful Infringement
The complaint alleges willful infringement of all asserted patents. This allegation is based on purported pre-suit knowledge stemming from at least two events: (1) Plaintiff’s filing of an ITC complaint against Defendant on October 21, 2019, and (2) Defendant’s alleged citation of the asserted patents during the prosecution of its own U.S. patent applications (Compl. ¶12, ¶17, ¶21, ¶26, ¶30, ¶35, ¶39, ¶44).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim scope: can the patent claims, which describe specific methods for diagnosing "operational efficiency" and calculating "thermal mass," be construed to cover the allegedly more generalized "big-data analytics and machine learning algorithms" of the Accused Products? The outcome will likely depend on the court's construction of key terms like "operational efficiency."
- A key evidentiary question will be one of technical proof: what will discovery reveal about the internal workings of the Nest Learning Thermostat? The case will turn on whether Plaintiff can show that the accused system actually performs the specific data comparisons and calculations recited in the claims, or if it achieves a similar outcome through a technically distinct, non-infringing method.
- A significant question for damages will be willfulness: the complaint makes specific allegations of pre-suit knowledge through both an ITC action and patent prosecution history. A central issue will be whether Defendant can establish a good-faith belief of non-infringement or invalidity sufficient to rebut the claim of willful infringement and the associated request for enhanced damages.