DCT

6:23-cv-00061

EcoFactor Inc v. Resideo Tech Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 6:23-cv-00061, W.D. Tex., 01/31/2023
  • Venue Allegations: Venue is alleged to be proper based on Defendant having a regular and established place of business in the district, specifically its company headquarters in Austin, Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s smart thermostat systems and associated backend services infringe patents related to calculating a building's thermal properties and evaluating HVAC system efficiency over time.
  • Technical Context: The technology at issue involves using networked smart thermostats and remote servers to analyze data and optimize residential energy consumption, a key area of competition in the smart home market.
  • Key Procedural History: The complaint does not allege any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the asserted patents.

Case Timeline

Date Event
2007-09-17 Priority Date for ’900 and ’649 Patents
2010-12-07 ’900 Patent Issued
2015-06-16 ’649 Patent Issued
2018-01-01 Defendant Establishes Austin HQ
2023-01-31 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,848,900 - "System and Method for Calculating the Thermal Mass of a Building" (Issued Dec. 7, 2010)

The Invention Explained

  • Problem Addressed: The patent describes conventional programmable thermostats as having a significant flaw: they operate on limited information—typically just the current indoor temperature and a user's setpoint. This approach fails to account for critical external variables like weather or the unique thermal characteristics of a building (i.e., its "thermal mass," or ability to retain or resist heat), leading to suboptimal comfort and energy waste ( '900 Patent, col. 1:50 - col. 2:50).
  • The Patented Solution: The invention proposes a networked climate control system where thermostats send data to a remote server. This server combines the thermostat data (internal temperature, HVAC status) with external data (e.g., weather forecasts) and building-specific profiles ('900 Patent, col. 5:5-23). By analyzing how the indoor temperature changes in response to HVAC operation and outside conditions, the server can calculate the building's effective thermal mass and use that model to make more intelligent control decisions, such as pre-cooling a well-insulated home before peak energy-cost periods ('900 Patent, Abstract; Fig. 11).
  • Technical Importance: This technology represented a shift from simple, time-based HVAC scheduling to dynamic, data-driven thermal modeling for individual homes, aiming to optimize both energy efficiency and occupant comfort ('900 Patent, col. 3:15-34).

Key Claims at a Glance

  • The complaint asserts claims 1-7 (Compl. ¶17). Independent claim 1 is representative.
  • Claim 1 (System):
    • An HVAC control system that receives temperature and status data from a location.
    • A database that stores this temperature data over time.
    • One or more processors that receive outside temperature data and compare it with expected internal temperatures.
    • The processors are configured to calculate a first rate of change in temperature when the HVAC system is "on" and a second rate of change when it is "off."
    • The processors then "relate" these first and second rates of change to the outside temperature measurements.

U.S. Patent No. 9,057,649 - "System and Method for Evaluating Changes in the Efficiency of an HVAC System" (Issued June 16, 2015)

The Invention Explained

  • Problem Addressed: The patent recognizes that HVAC systems can degrade in performance over time due to mechanical issues like clogged filters or refrigerant leaks. While this results in higher energy bills, diagnosing the specific fault is difficult for a homeowner or a simple thermostat ('900 Patent, col. 3:35-50).
  • The Patented Solution: The invention describes a system that evaluates changes in HVAC efficiency by monitoring performance data over time. The system compares a building's current HVAC performance (e.g., cycle times needed to achieve a temperature change) against its own historical performance and, in some embodiments, against the performance of HVAC systems in other, similar houses ('900 Patent, col. 9:10-26; '649 Patent, col. 13:30-48). Detecting a deviation from the historical or peer-group baseline indicates a drop in efficiency, and the specific "signature" of this degradation can help diagnose the underlying problem ('900 Patent, Fig. 12).
  • Technical Importance: This technology extends the concept of a smart thermostat from merely optimizing a healthy system to providing ongoing diagnostics and predictive health monitoring for the HVAC equipment itself ('900 Patent, col. 9:40-44).

Key Claims at a Glance

  • The complaint asserts claims 1-14 (Compl. ¶29). Independent claims 1 and 8 are asserted.
  • Claim 1 (System):
    • An HVAC control system for a first structure that receives temperature and status data.
    • Processors that receive outside temperature data and compare it with the structure's temperature measurements over time.
    • A database that stores temperature data from the structure.
    • The processors compare an inside temperature at one time with an inside temperature at a different time to "determine whether the operational efficiency of the HVAC system has decreased over time."
  • Claim 8 (System):
    • A first HVAC control system for a first structure and a second HVAC control system for a second structure.
    • Processors that receive outside temperature data and "compare said temperature measurements from said first HVAC system and said second HVAC system" over time "to determine the efficiency of the first HVAC system and the second HVAC system."
    • A database storing temperature measurements from both systems.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendant's "smart thermostat systems," including the Resideo T5, T6, T9, and T10 Pro Smart Thermostats, as well as various WiFi-enabled thermostat models (Compl. ¶10, ¶17, ¶29). The allegations also encompass the entire supporting ecosystem, which includes Defendant's "servers, backend systems, web portals, APIs, mobile applications, and remote sensor accessories" (Compl. ¶17).

Functionality and Market Context

  • The complaint alleges the accused products constitute a system with a "frontend" device (the thermostat in a user's home) and a "backend" infrastructure (Defendant's servers and data centers) (Compl. ¶13). These thermostats are described as connecting to the internet to communicate with the backend, allowing for remote control via mobile apps and the transmission of temperature and HVAC system data over the network (Compl. ¶11-13). The complaint asserts these systems analyze the gathered data to provide smart energy management features to end users (Compl. ¶12).

IV. Analysis of Infringement Allegations

The complaint references external claim chart exhibits (Exhibits 2 and 4) that were not included with the pleading, and it does not contain claim charts in the body of the document (Compl. ¶21, ¶33). The infringement theory is therefore summarized below in prose.

No probative visual evidence provided in complaint.

  • ’900 Patent Infringement Allegations: Plaintiff’s infringement theory appears to be that the combination of a Resideo thermostat and its backend servers creates a system that practices the claimed invention. The theory suggests that the thermostat measures the indoor temperature and HVAC status (on/off), which is sent to Resideo's servers. These servers allegedly also receive outside weather data. The servers' processors then purportedly analyze this combined data to calculate how quickly the house's temperature changes when the HVAC is on versus when it is off, and relate this behavior to outside conditions to model the home's thermal characteristics, thereby meeting the limitations of claim 1 (Compl. ¶17-21).

  • ’649 Patent Infringement Allegations: The complaint alleges that the accused systems evaluate HVAC efficiency over time. For claim 1, the theory is that Resideo's servers collect and store operational data from a customer's HVAC system and compare its performance at different points in time to determine if efficiency has degraded (Compl. ¶29-33). For claim 8, the complaint appears to allege that Resideo's backend platform pools data from many different customers ("first HVAC system" and "second HVAC system") and compares their performance against one another to determine their relative efficiency (Compl. ¶29-33).

  • Identified Points of Contention:

    • Technical Questions: A central evidentiary question will be what specific algorithms are executed on Resideo's backend servers. The complaint alleges functionality that maps to the claims, but the case may turn on whether discovery reveals that the accused systems actually perform the specific calculations recited in the claims (e.g., calculating separate "on" and "off" rates of change per the ’900 patent).
    • Scope Questions: For the ’649 patent, a key dispute may arise over the meaning of "determine whether the operational efficiency... has decreased." The question for the court could be whether this requires a discrete determination and alert, versus a continuous, adaptive learning process that implicitly accounts for performance changes without making an explicit finding of "decreased efficiency." Similarly, for claim 8, a question will be whether any use of aggregated, anonymized customer data for general modeling constitutes "comparing" a "first" and "second" system to "determine the efficiency" of each.

V. Key Claim Terms for Construction

  • Term: "calculate one or more first rates of change in temperature... during which the status of the HVAC system is 'on' and... one or more second rates of change... during which the status... is 'off'" ('900 Patent, Claim 1)

    • Context and Importance: This phrase recites the core computational step of the invention. Infringement will hinge on whether the accused system's thermal modeling algorithm performs this specific two-part analysis of temperature change rates based on the HVAC's on/off status.
    • Intrinsic Evidence for a Broader Interpretation: The patent describes the overall goal as calculating a "thermal mass index" to understand the building's thermal properties, which might support an argument that any method achieving this goal using on/off cycle data is covered ('900 Patent, col. 11:7-12; Fig. 11).
    • Intrinsic Evidence for a Narrower Interpretation: The claim language explicitly separates the calculation into two distinct rates ("first" for "on," "second" for "off"). This structure may support a narrower construction requiring two separate calculations, as opposed to a single, unified modeling equation that implicitly considers both states.

  • Term: "compare said temperature measurements from said first HVAC system and said second HVAC system... to determine the efficiency" ('649 Patent, Claim 8)

    • Context and Importance: This term is critical because it appears to require cross-customer data comparison. The viability of this claim depends on whether Resideo is found to be comparing distinct user systems against each other for the purpose of determining their individual or relative efficiency.
    • Intrinsic Evidence for a Broader Interpretation: The specification discusses comparing a house's performance to "other nearby houses" generally, which could support reading the claim to cover any form of peer-group analysis or benchmarking ('900 Patent, col. 9:18-20).
    • Intrinsic Evidence for a Narrower Interpretation: The specification discusses ranking a home's performance by percentile relative to other homes ('900 Patent, col. 9:22-26). This could support a narrower reading that requires a direct comparison generating a relative efficiency metric, not just using aggregated data to refine a general model.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, asserting that Defendant, with knowledge of the patents (at least from the date of the complaint), provides user manuals and instructions that encourage customers to use the accused systems in an infringing manner (Compl. ¶19, ¶31). It also pleads contributory infringement, alleging the accused products are specially adapted for infringement and are not staple articles with substantial non-infringing uses (Compl. ¶20, ¶32).
  • Willful Infringement: The complaint alleges willful infringement based on Defendant's continued infringement after having knowledge of the patents, with knowledge alleged to exist from at least the filing and service of the complaint (Compl. ¶24, ¶36).

VII. Analyst’s Conclusion: Key Questions for the Case

  1. A primary issue will be one of evidentiary proof: What do Resideo's proprietary backend algorithms actually do? The dispute will likely focus on evidence obtained in discovery regarding the specific calculations performed by the accused systems to see if they align with the methods claimed in the patents, such as calculating distinct "on" and "off" temperature change rates.

  2. The case may present a question of claim scope and application: Does Resideo's use of aggregated data from its user base, if any, constitute "comparing" a "first HVAC system" and a "second HVAC system" to "determine... efficiency" as required by claim 8 of the ’649 patent? This will involve construing the claim's requirement for inter-system comparison.

  3. A potential underlying legal question is that of divided infringement: Since the claims require actions from both the end-user's thermostat and the defendant's backend servers, a central issue will be whether Plaintiff can prove that Resideo "directs or controls" the actions of its users to a degree sufficient to be liable for direct infringement of the entire system claim.