DCT
3:24-cv-01061
Kbent LLC v. First Co
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: KBEnt. LLC (Wyoming)
- Defendant: First Co. (Texas)
- Plaintiff’s Counsel: Charhon Callahan Robson & Garza, PLLC; Knobbe Martens Olson & Bear, LLP
- Case Identification: 3:24-cv-01061, N.D. Tex., 05/01/2024
- Venue Allegations: Venue is alleged to be proper as Defendant is a Texas corporation that resides in the judicial district and has purportedly committed acts of infringement within the district.
- Core Dispute: Plaintiff alleges that Defendant’s HVAC product line infringes a patent related to systems and methods for automatically mitigating ice formation on an indoor evaporator coil.
- Technical Context: The technology addresses the common HVAC problem of ice buildup on evaporator coils, which can impair performance and cause system damage, by using a sensor and processor to shut down the unit when freezing conditions are detected.
- Key Procedural History: The complaint states that Plaintiff’s predecessor in interest sent two letters to Defendant, on March 30, 2023, and June 7, 2023, providing notice of the patent and the alleged infringement, to which Defendant allegedly did not respond.
Case Timeline
| Date | Event |
|---|---|
| 2017-10-19 | U.S. Patent No. 10,976,066 Priority Date |
| 2021-04-13 | U.S. Patent No. 10,976,066 Issued |
| 2023-03-30 | Plaintiff's predecessor sent first notice letter to Defendant |
| 2023-06-07 | Plaintiff's predecessor sent second notice letter to Defendant |
| 2024-05-01 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,976,066 - "Systems and methods for mitigating ice formation conditions in air conditioning systems"
- Issued: April 13, 2021
The Invention Explained
- Problem Addressed: The patent’s background section identifies the technical problem of ice formation on the indoor evaporator coils of air conditioning systems, which can lead to reduced cooling, property damage from melting ice, and system failure (’066 Patent, col. 1:33-42; Compl. ¶9).
- The Patented Solution: The invention is a control system that uses a temperature sensor placed in thermal contact with the evaporator coil. A hardware processor monitors data from the sensor and compares the coil’s temperature to a pre-set threshold. If the temperature drops to or below the threshold, indicating a risk of icing, the processor actuates a relay to shut off the air conditioning system and generates a maintenance notification for the user. The system is designed to remain off until it receives a specific user input to reset it (’066 Patent, Abstract; col. 2:5-48).
- Technical Importance: This automated monitoring and shutdown sequence provides a protective function to prevent a common mode of HVAC system damage, thereby avoiding potentially costly repairs and secondary issues like water damage (Compl. ¶¶9-10).
Key Claims at a Glance
- The complaint asserts independent system Claim 1 and independent method Claim 12 (Compl. ¶¶22, 35).
- The essential elements of independent Claim 1 include:
- A temperature sensor attached to the indoor evaporator coil configured to generate thermal data.
- A hardware processor and a memory device storing a threshold value and machine-readable instructions.
- Instructions that cause the processor to compare a temperature parameter derived from the sensor data to the threshold value.
- Upon determining the temperature is less than or equal to the threshold, the processor actuates a relay to stop system operation and generates a notification signal.
- A user interface device displays a maintenance notification that prompts a user input.
- The processor prevents system operation prior to receipt of the user input.
- The processor resets the relay and restores operation upon receipt of the user input.
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are products from Defendant’s “Eco Series product line,” including those sold under the names COOL PAK, FRESH PAK, and AQUA PAK. The complaint uses the Fresh-Pak product as an exemplary infringing product (Compl. ¶14, 22).
Functionality and Market Context
- The complaint alleges the accused products are HVAC systems for the multi-family industry (Compl. ¶12). Their relevant functionality is described as "Evaporator coil low temperature protection," where "a temperature sensor attached to the coil will de-energize the Fresh-Pak unit" if it detects a low temperature or reduced airflow condition (Compl. ¶23). The products allegedly include a "multi-function micro-processor board" that implements this feature (Compl. ¶25).
- The complaint provides a screenshot of a product video, stating "one board has a diagnostic line on it which will help" (Compl. ¶31, p. 9).
- The complaint alleges that for critical "A-Alarms," the accused product's operation is "locked in shut down mode until the alarm is acknowledged and reset" by a user (Compl. ¶32, p. 10). The complaint includes a state diagram from the product manual illustrating this locked-out, user-resettable alarm sequence (Compl. ¶32, p. 10).
IV. Analysis of Infringement Allegations
- ’066 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a temperature sensor responsive to thermal energy of the indoor evaporator coil, the temperature sensor attached to the indoor evaporator coil... comprising a thermal contact in thermal communication with the indoor evaporator unit... | The Fresh-Pak product includes a temperature sensor attached to the indoor evaporator coil that monitors for a "low temperature condition that could result in ice build up on the coil." | ¶24 | col. 9:11-19 |
| a hardware processor in electronic communication with the temperature sensor; | The product includes a "multi-function micro-processor board" that is in electronic communication with the sensor and includes functions for "Evaporator coil low temperature protection." | ¶25 | col. 9:20-22 |
| a memory device in electronic communication with the hardware processor, the memory device storing information comprising a threshold temperature value and machine readable instructions... | The product includes a memory device storing instructions and a threshold temperature value, which is alleged to be 40°F for the "Low ambient lockout" feature. | ¶26 | col. 9:23-27 |
| in response to determining that ice formation conditions are present, actuate a relay to stop operation of the open-environment system for cooling and/or dehumidifying an interior space and generate a notification signal indicating that ice formation conditions are present | The processor is instructed to "de-energize the Fresh-Pak unit" when a low temperature is detected. A table of alarm codes from the product manual shows that alarm code 1005, for a "Frost protection temperature" fault, results in "Shutdown AHU" and triggers "Frost protection mode." This is alleged to be the actuation of a relay and generation of a notification signal (Compl. ¶31, p. 9). | ¶31 | col. 9:40-44 |
| a user interface device comprising a display configured to display a maintenance notification in response to the hardware processor generating the notification signal, the maintenance notification prompting a user input | The product includes a user interface that displays a maintenance notification. An alarm state diagram shows that "critical A-Alarms" lock the system in a shutdown mode until the alarm is acknowledged and reset, which is alleged to be a prompt for user input (Compl. ¶32, p. 10). | ¶32 | col. 9:45-49 |
| wherein the hardware processor prevents operation of the open-environmental system... prior to receipt of the user input | The product manual's alarm state diagram allegedly shows that for critical alarms, the system is "locked in shut down mode" and operation is prevented until a user acknowledges and resets the alarm. | ¶33 | col. 9:50-53 |
| wherein the hardware processor resets the relay and restores operation of the open-environmental system... upon receipt of the user input | The processor allegedly restores operation after the user provides input to acknowledge and reset the alarm, moving the system from an "ALARM, ACKED" state back to "NORMAL, UNLOCKED." | ¶34 | col. 9:54-58 |
- Identified Points of Contention:
- Technical Questions: A key technical question is whether the standard "Evaporator coil low temperature protection" feature, which product specifications state will "re-energize the Fresh-Pak unit when the coil warms back up" (Compl. ¶23), is the same as the "Frost protection" critical A-Alarm (Compl. ¶31), which allegedly requires a user reset. The infringement theory may depend on demonstrating that the low-temperature condition invariably triggers a critical alarm that locks the system, rather than an auto-recovering fault condition.
- Scope Questions: A potential dispute over claim scope concerns the term "user input." The complaint alleges that acknowledging and resetting a critical alarm satisfies this limitation. The question for the court may be whether the automatic "re-energize" function described in some product literature (Compl. ¶23) falls outside the claim scope, which requires the system to prevent operation until user input is received.
V. Key Claim Terms for Construction
The Term: "user input"
Context and Importance: This term is central because it distinguishes the patented invention from a simple automatic thermostat. The patent requires an interactive step where the system remains off until a user acts. The complaint alleges the accused product's "A-Alarm" reset protocol meets this limitation, but other descriptions of the product suggest an automatic recovery. The definition of what constitutes the required "user input" will be critical to the infringement analysis.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification describes the input in general terms, such as an input received from a user via a user interface device, which could be a thermostat or mobile device, to "reset the relay" (’066 Patent, col. 8:59-67).
- Evidence for a Narrower Interpretation: The claim language links the "user input" to a "maintenance notification" that prompts the input, and the result is to "reset the relay" and "restore operation" (’066 Patent, col. 9:47-58). This suggests the "user input" must be a specific, solicited action in response to an alert, not merely a power cycle or automatic system recovery.
The Term: "maintenance notification"
Context and Importance: Practitioners may focus on this term because the nature of the alert is specified. The claim requires more than just an error code; it requires a "notification" that prompts user input. Defendant may argue its system provides only an informational fault code (e.g., "Frost protection temperature for heating coil, sensor fault" from the table at Compl. ¶31, p. 9) that does not explicitly solicit user action in the manner required.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification notes the notification can be simple, such as "a form of a light," text, or sound (’066 Patent, col. 6:49-52).
- Evidence for a Narrower Interpretation: Claim 1 explicitly requires the "maintenance notification" to be one that is "prompting a user input" (’066 Patent, col. 9:49). This suggests a functional requirement that the notification must actively solicit interaction, a feature the complaint alleges is present in the "A-Alarms" state diagram where the system waits for acknowledgement (Compl. ¶32, p. 10).
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement of method Claim 12, asserting that Defendant provides technical specifications, installation manuals, and operation guides on its website that instruct and encourage customers and end-users to install and use the accused products in an infringing manner (Compl. ¶35).
- Willful Infringement: The willfulness allegation is based on alleged pre-suit knowledge. The complaint asserts that Defendant knew of the ’066 Patent and its alleged infringement since at least March 30, 2023, the date of the first of two notice letters sent by Plaintiff’s predecessor (Compl. ¶37).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of operational equivalence: Does the accused product's "low temperature protection," which product literature describes as automatically re-energizing upon warming, function in the same manner as the patented method, which requires the system to remain stopped until a specific "user input" is received? The resolution will depend on evidence clarifying whether a low-temperature event invariably triggers a critical "A-Alarm" that necessitates a manual user reset.
- A key evidentiary question will concern the nature of the notification: Does the "Frost protection" alarm code generated by the accused system constitute a "maintenance notification prompting a user input" as claimed, or is it merely an informational status alert? The outcome may depend on how the user interface and system logic are shown to operate in practice, beyond the high-level diagrams provided in the complaint.