3:21-cv-01496
Resideo Tech Inc v. EcoFactor Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Resideo Technologies Inc. (Delaware)
- Defendant: EcoFactor, Inc. (Delaware)
- Plaintiff’s Counsel: Steptoe & Johnson, LLP
- Case Identification: 3:21-cv-01496, N.D. Cal., 03/02/2021
- Venue Allegations: Venue is alleged to be proper in the Northern District of California because Defendant EcoFactor, Inc. resides in the district, with a principal place of business in Palo Alto.
- Core Dispute: Plaintiff Resideo seeks a declaratory judgment that its smart thermostat products do not infringe four patents owned by Defendant EcoFactor related to evaluating and improving HVAC system efficiency.
- Technical Context: The technology at issue involves network-connected thermostats that use internal and external data to monitor, diagnose, and optimize the performance of residential and commercial heating, ventilation, and air conditioning (HVAC) systems.
- Key Procedural History: This declaratory judgment action was filed in response to a complaint EcoFactor filed with the International Trade Commission (ITC) on February 26, 2021, which accused Resideo of infringing the same four patents. Subsequent to the filing of this complaint, two of the asserted patents (the '567 and '983 patents) had numerous claims cancelled in Inter Partes Review (IPR) proceedings. The '322 patent was also amended in an earlier Ex Parte Reexamination. These post-grant proceedings may significantly narrow the scope of the dispute and limit the claims available for EcoFactor to assert.
Case Timeline
| Date | Event |
|---|---|
| 2007-09-17 | Earliest Priority Date for all Asserted Patents |
| 2011-09-13 | U.S. Patent No. 8,019,567 Issues |
| 2013-04-16 | U.S. Patent No. 8,423,322 Issues |
| 2014-11-11 | U.S. Patent No. 8,886,488 Issues |
| 2020-04-07 | U.S. Patent No. 10,612,983 Issues |
| 2021-02-26 | EcoFactor files related ITC Complaint against Resideo |
| 2021-03-02 | Resideo files this Complaint for Declaratory Judgment |
| 2021-05-19 | IPR Filed Against ’983 Patent (IPR2021-00982) |
| 2021-07-26 | IPR Filed Against ’567 Patent (IPR2021-01218) |
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 conventional thermostats as being limited because they do not account for external conditions, a building's thermal properties ("thermal mass"), or dynamic degradation in HVAC system performance from issues like clogged filters or refrigerant leaks, leading to inefficiency and wasted energy (’322 Patent, col. 1:46-col. 3:64).
- The Patented Solution: The invention proposes a network-connected climate control system that gathers data from multiple sources: temperature measurements from within the conditioned building and outside temperature data from an external source (e.g., the internet) (’322 Patent, col. 4:5-14). A processor then compares the HVAC system's performance over time by analyzing inside and outside temperatures at different points in time to determine if the system's operational efficiency has decreased (’322 Patent, Abstract; col. 4:40-56).
- Technical Importance: This data-driven approach allows the system to diagnose drops in HVAC efficiency and potentially identify the cause without requiring additional, costly hardware to be installed within the HVAC machinery itself (’322 Patent, col. 3:60-64).
Key Claims at a Glance
- The complaint asserts non-infringement of the patent's claims, focusing on limitations found in independent claim 1, which was amended during an ex parte reexamination. The right to contest other claims is reserved.
- Essential elements of amended independent claim 1 include:
- An HVAC control system that receives temperature and status from a first structure.
- One or more processors that receive outside temperature measurements from a different source.
- The processors compare inside and outside temperature over time.
- The processors compare the HVAC system's performance at a first time with its performance at a second, different time.
- This comparison is used "to determine whether the operational efficiency of the HVAC system has decreased over time."
- A pattern of the decrease is compared to stored patterns associated with specific defects to determine a possible cause.
U.S. Patent No. 8,019,567 - "System and Method for Evaluating Changes in the Efficiency of an HVAC System"
Issued September 13, 2011
The Invention Explained
- Problem Addressed: The patent notes that while HVAC problems like clogged filters or refrigerant leaks manifest as higher energy bills, the unique "signature" of each problem is hidden within the system's operational data, making diagnosis difficult for a homeowner ('567 Patent, col. 3:39-58).
- The Patented Solution: The invention describes a system that uses processors to compare inside and outside temperature data over time to create an "estimation for the rate of change in inside temperature" when the HVAC system is in a state of repair ('567 Patent, col. 4:28-36). This baseline estimation is then compared with a later, recorded inside temperature to determine if the system's efficiency has declined. If a decline is found, the system analyzes the changes over time to suggest a specific cause of the degradation ('567 Patent, Abstract; col. 4:37-45).
- Technical Importance: The technology aims to automate fault diagnosis by using historical and real-time performance data to distinguish between different types of system failures, such as a slow degradation typical of a clogged filter versus a more rapid decline indicative of a refrigerant leak ('567 Patent, Fig. 12; col. 11:45-col. 12:4).
Key Claims at a Glance
- The complaint asserts non-infringement of limitations found in original independent claims 1 and 15. However, a subsequent IPR proceeding (IPR2021-01218) resulted in the cancellation of claims 1-3, 7, and 15-20. EcoFactor may now only assert the surviving claims 4-6 and 8-14.
- For context, essential elements of the now-cancelled independent claim 1 included:
- Processors that compare inside and outside temperature over time to "derive an estimation for the rate of change in inside temperature."
- Processors that compare a recorded inside temperature with that "estimation" to determine if operational efficiency has decreased.
- If efficiency has decreased, processors analyze the changes to "suggest a cause of degradation."
U.S. Patent No. 10,612,983 - "System and Method for Evaluating Changes in the Efficiency of an HVAC System"
Issued April 7, 2020
Technology Synopsis
This patent focuses on a system that predicts the time required for an HVAC system to change the building's temperature to a specified setpoint. The prediction is based on three inputs: data from a sensor inside the building, data from an external network connection (e.g., outdoor weather), and the user's temperature setpoint (’983 Patent, Abstract). The system then controls the HVAC unit based on this prediction to achieve the target temperature at the target time (’983 Patent, col. 13:51-col. 14:14).
Asserted Claims
The complaint contests limitations found in original independent claims 1 and 24 (Compl. ¶33). A subsequent IPR proceeding (IPR2021-00982) cancelled claims 1-7 and 10-19, leaving claims 20-30 as patentable.
Accused Features
The predictive scheduling and temperature control features of Resideo's smart thermostats are the subject of the infringement dispute (Compl. ¶33).
U.S. Patent No. 8,886,488 - "System and Method for Calculating the Thermal Mass of a Building"
Issued November 11, 2014
Technology Synopsis
This patent discloses a system for calculating the "thermal mass" of a building, which represents its ability to resist temperature changes. The system uses processors to receive inside and outside temperature data and calculates one or more "predicted rates of change" for the inside temperature based on the HVAC system's status (’488 Patent, Abstract; col. 3:6-15). This calculated thermal mass can then be used to more accurately and efficiently control the HVAC system (’488 Patent, col. 4:18-35).
Asserted Claims
The complaint contests limitations found in independent claims 1 and 9 (Compl. ¶39).
Accused Features
The features of Resideo's products that model a building's thermal properties to predict and control temperature are accused of infringement (Compl. ¶39).
III. The Accused Instrumentality
Product Identification
The Accused Products are a range of Resideo's smart thermostats, including the Wi-Fi Smart Thermostat, T-series Smart Thermostats (T5, T5+, T6 Pro, T9, T10 Pro), WiFi 9000 Color Touchscreen Thermostat, and The Round Smart Thermostat (Compl. ¶2).
Functionality and Market Context
The complaint, being a declaratory judgment action for non-infringement, does not affirmatively describe the functionality of the Accused Products. Instead, it states that EcoFactor's ITC complaint accuses these products of being "smart thermostat systems, smart HVAC systems, smart HVAC control systems, and components thereof" (Compl. ¶2). The core of Resideo's position is a denial that its products practice the specific methods recited in the asserted patents (Compl. ¶¶ 21, 27, 33, 39). The complaint does not provide sufficient detail for an independent analysis of the Accused Products' functionality.
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’322 Patent Infringement Allegations
| Claim Element (from Amended Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| one or more processors that receive measurements of outside temperatures from at least one source other than said HVAC system and compare said temperature measurements from said first structure... | Processors that compare inside temperature with outside temperature obtained from a remote source. Resideo denies its products perform the full comparison as claimed. | ¶21 | col. 4:7-12 |
| wherein said one or more processors compares (a) first performance of the HVAC system for an inside temperature recorded inside the first structure... at a first time and (b) second performance... at a second time... | Processors that compare HVAC performance metrics from two different points in time. Resideo denies its products perform this specific longitudinal comparison. | ¶21 | col. 4:48-52 |
| ...to determine whether the operational efficiency of the HVAC system has decreased over time. | Processors that use the comparison of performance over time to make a specific determination that the system's operational efficiency has declined. Resideo denies its products make this determination. | ¶21 | col. 4:52-54 |
’567 Patent Infringement Allegations
| Claim Element (from Cancelled Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| ...wherein said one or more processors compares the inside temperature of said first structure and the outside temperature over time to derive an estimation for the rate of change in inside temperature... | Processors that analyze temperature data to create a baseline model or "estimation" of the building's thermal performance. Resideo denies its products derive such an estimation. | ¶27 | col. 13:30-34 |
| wherein said one or more processors compares an inside temperature recorded inside the first structure with said estimation... to determine whether the operational efficiency of the HVAC system has decreased over time... | Processors that compare a current temperature against the previously derived "estimation" to detect a drop in efficiency. Resideo denies its products perform this comparison. | ¶27 | col. 13:40-45 |
| wherein if said operational efficiency has decreased, said one or more processors analyzes the changes in the operational efficiency over time to suggest a cause of degradation. | Processors that, upon detecting an efficiency drop, perform further analysis to diagnose and suggest a specific cause (e.g., clogged filter). Resideo denies its products perform this diagnostic step. | ¶27 | col. 13:46-49 |
Identified Points of Contention
- Procedural Impact of IPRs: A threshold issue is that the complaint contests claims of the '567 and '983 patents that were subsequently cancelled in IPRs. This raises the question of how EcoFactor can proceed with its infringement case, as it must now rely on the surviving claims, which may not align with its original infringement theories.
- Scope Questions: The dispute raises questions about the scope of the claimed methods. A key question is whether the patents' specific, multi-step methods for calculating efficiency decline and diagnosing faults (e.g., comparing performance at two distinct times under the '322 patent, or comparing a value to a baseline "estimation" under the '567 patent) read on the more general-purpose, adaptive learning algorithms that may be used in the Accused Products.
- Technical Questions: A central technical question is what specific calculations the Accused Products actually perform. The case will require evidence on whether Resideo's thermostats generate a specific "estimation for the rate of change" or a longitudinal "decrease in operational efficiency" as defined by the patents, or if they operate on different principles.
V. Key Claim Terms for Construction
The Term: "operational efficiency of the HVAC system"
’322 Patent, amended claim 1
Context and Importance
Resideo's non-infringement argument hinges on its denial that its products determine whether "operational efficiency... has decreased over time" (Compl. ¶21). The definition of this term is therefore central. Practitioners may focus on this term because its construction will determine whether a specific, quantifiable metric is required or if a more general observation of performance degradation meets the limitation.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: The specification links inefficiency to common-sense outcomes like "higher energy bills" and changes in "cycle times," which could support a broader definition not tied to a single formula (’322 Patent, col. 3:48-60).
- Evidence for a Narrower Interpretation: The patent describes diagnosing specific problems (clogged filters, leaks) that have unique performance "signatures," suggesting "operational efficiency" is a specific diagnostic metric calculated by the system to identify these signatures (’322 Patent, col. 3:45-53; Fig. 12).
The Term: "estimation for the rate of change in inside temperature"
’567 Patent, cancelled claim 1
Context and Importance
This term is critical because the patent's method requires creating this "estimation" as a baseline and then comparing a later temperature to it. Resideo denies its products perform this step (Compl. ¶27). Although this claim is cancelled, similar concepts may appear in surviving claims, making its interpretation relevant.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: The word "estimation" is inherently general and could arguably cover any form of predictive thermal modeling.
- Evidence for a Narrower Interpretation: The claim specifies the estimation is derived when the HVAC system is in a "first state of repair," suggesting it is a specific baseline or benchmark value, not just any prediction. The specification also describes calculating a "thermal mass index," which could be argued as the specific type of "estimation" required by the claims (’567 Patent, col. 11:13-39).
VI. Other Allegations
Indirect Infringement
The complaint notes that EcoFactor's underlying ITC action alleges that Resideo infringes "either directly or indirectly under a theory of inducement or contributory infringement" (Compl. ¶16). The complaint denies these allegations but does not provide the specific facts EcoFactor relies on to support them (Compl. ¶¶ 21, 27, 33, 39).
Willful Infringement
The complaint does not contain allegations of willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A primary issue is the procedural posture of the case in light of the IPRs that cancelled or amended key asserted claims after this complaint was filed. The viability of EcoFactor's infringement suit will depend on its ability to assert the surviving claims against Resideo's products, potentially requiring a significant reframing of its original theories.
- A key technical question will be one of methodological scope: do the Accused Products' algorithms for optimizing performance perform the specific, sequential comparisons required by the patent claims—such as a historical comparison to find a "decrease" in "operational efficiency" ('322 patent) or the creation and use of a baseline "estimation" to diagnose faults ('567 patent)? Or is there a fundamental mismatch between the patents' specific diagnostic methods and the general predictive control used by the accused thermostats?
- The case will also turn on a definitional question: can terms like "operational efficiency" and "estimation" be construed broadly to encompass any form of predictive thermal modeling, or are they limited by the specification to the specific calculations and diagnostic "signatures" disclosed in the patent embodiments?