PTAB

IPR2020-01504

Google LLC v. EcoFactor Inc

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Reducing the Cycling Time of a Climate Control System
  • Brief Description: The ’753 patent describes methods for optimizing the operation of climate control (HVAC) systems to reduce energy consumption. The system determines a structure's thermal performance values, calculates an optimal start time to reach a target temperature by a target time, and uses a series of intermediate setpoints during the recovery period to gradually change the temperature.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are obvious over Wedekind in view of Ehlers.

  • Prior Art Relied Upon: Wedekind (Patent 5,197,666) and Ehlers (Patent 6,216,956).
  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that the combination of Wedekind and Ehlers taught all limitations of the challenged claims. Wedekind was asserted to disclose a sophisticated HVAC control system that uses a "non-linear efficiency model" to optimize energy consumption. This model determines building and HVAC parameters (thermal performance values) from historical indoor and outdoor temperatures to predict the "optimum start time" for a recovery period (e.g., heating a house before an occupant wakes up). However, Wedekind did not explicitly teach using forecasted temperatures or "temperature ramping" (using a plurality of intermediate setpoints) during the recovery period.

      Petitioner contended that Ehlers supplied these missing elements. Ehlers was presented as teaching the use of "temperature ramping" to gradually change the setpoint during recovery. This technique avoids activating less-efficient, multi-stage heating or cooling systems that engage when there is a large difference between the actual temperature and the setpoint. Ehlers also explicitly taught obtaining and using weather forecast data to more accurately predict the time needed to heat or cool a building. Petitioner argued that adding Ehlers’ teachings of temperature ramping and the use of weather forecasts to Wedekind's base system rendered the challenged claims obvious.

      The arguments for independent claims 1, 9 (heating-specific), and 15 (cooling-specific) were substantially similar, with minor distinctions based on the direction of temperature change. Dependent claims 2-8 and 10-14, and 16-20 were argued to be obvious as they recited conventional features of such systems (e.g., use in a single-family residence, a programmable thermostat, or a remote processor), all of which were allegedly taught or made obvious by the combination.

    • Motivation to Combine: Petitioner asserted that a person of ordinary skill in the art (POSA) would have been motivated to combine the references. Both Wedekind and Ehlers are in the same field of HVAC energy management and address the same problem of optimizing energy consumption while maintaining user comfort. A POSA seeking to improve upon Wedekind's system would have recognized the known benefits of temperature ramping and using weather forecasts, as taught by Ehlers, to increase efficiency and accuracy. Ehlers’ techniques were presented as known, common-sense improvements for a system like Wedekind’s.

    • Expectation of Success: A POSA would have had a reasonable expectation of success in combining the references. The petition argued that the art of HVAC control was predictable and that integrating the known techniques of ramping and forecast usage from Ehlers into Wedekind's system would have involved routine modifications.

4. Key Claim Construction Positions

  • For the purposes of the petition, Petitioner adopted the constructions proposed by the Patent Owner in a co-pending ITC investigation. Key constructions included:
    • "thermal performance values": "values indicating a rate of change of temperature in said structure in response to changes in outside temperature"
    • "performance characteristic [of said...climate control...system]": "characteristic that is indicative of a capability to change inside temperature"
    • "heating, ventilation, and air conditioning system": "a group of components working together to move heat or remove heat from the conditioned [structure/location]"

5. Key Technical Contentions (Beyond Claim Construction)

  • A central technical contention was that Wedekind’s disclosure of a "non-linear efficiency model" inherently taught the claimed "thermal performance values." Petitioner argued that Wedekind’s model uses a set of differential equations that correlate inside and outside temperatures over time to calculate several specific parameters (e.g., effective thermal capacitance (Mcv), internal heat transfer conductance (hA), and external heat transfer conductance (UoAo)). Petitioner contended that because these parameters are used in equations that model the rate of change of inside temperature (dT'/dt) as a function of outside temperature, they directly met the claim limitation of "values indicat[ing] a rate of change of temperature...in response to changes in outside temperatures," as construed by the Patent Owner.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-20 of the ’753 patent as unpatentable under 35 U.S.C. §103.