Cedar Lane Tech Inc v. Greystone Energy Systems Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cedar Lane Technologies Inc. (Canada)
  • Defendant: Greystone Energy Systems Inc. (Canada)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-01148, E.D. Tex., 11/24/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation and has committed acts of patent infringement in the district.
• Core Dispute: Plaintiff alleges that Defendant’s ventilation control products infringe a patent related to using air quality sensors to automatically control ventilation blowers.
• Technical Context: The technology at issue involves automated control systems for residential and commercial heating, ventilation, and air conditioning (HVAC) systems, specifically methods for upgrading existing systems to respond to real-time air quality data.
• Key Procedural History: The complaint does not reference any prior litigation, licensing history, or post-grant proceedings involving the patent-in-suit.

Case Timeline

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

U.S. Patent No. 7,632,178 - "Ventilation blower controls employing air quality sensors"

• Patent Identification: U.S. Patent No. 7,632,178, “Ventilation blower controls employing air quality sensors,” issued December 15, 2009 (’178 Patent). (Compl. ¶¶ 8-9).

The Invention Explained

• Problem Addressed: The patent describes the inadequacy of conventional ventilation systems that rely on manual switches or simple occupancy detectors. Such systems are often ineffective because occupants may forget to activate them, or they may run unnecessarily, failing to remove contaminants like high humidity or odors efficiently. (’178 Patent, col. 2:7-15).
• The Patented Solution: The invention provides a method for retrofitting an existing ventilation system that has a "Remote Switch" input for high-speed operation. The solution involves adding at least one air quality sensor (e.g., for carbon monoxide, smoke, or humidity) and connecting it to a relay. When a sensor detects a contaminant, it activates the relay, which in turn connects to the ventilation system's remote switch terminals, forcing the system into a continuous, high-speed mode to evacuate the contaminated air. (’178 Patent, Abstract; col. 2:33-58). Figure 3 illustrates multiple sensors (26, 27, 28) wired in parallel to control a single relay (32) that simulates the operation of a manual wall switch (20). (’178 Patent, Fig. 3).
• Technical Importance: This approach allows for the upgrade of existing ventilation systems to become "smart" and responsive to actual air quality conditions without requiring a complete replacement of the core system controller. (’178 Patent, col. 2:33-37).

Key Claims at a Glance

• The complaint asserts infringement of one or more claims of the ’178 Patent, referencing "Exemplary '178 Patent Claims" in an attached but unprovided exhibit. (Compl. ¶¶ 11, 16). Independent claim 1 is representative of the patented method.
• Essential Elements of Independent Claim 1:
  • A method of retrofitting an existing ventilation system in a building.
  • The existing system has fans for exhausting stale air and bringing in fresh air, and at least one remote switch terminal for setting a high-speed mode.
  • Adding a relay to the existing system.
  • Inserting at least one air quality sensor in a specific location.
  • Connecting the relay's contacts to the remote switch terminals.
  • Connecting the air quality sensor(s) in a parallel network to the relay.
  • The relay is activated to set the high-speed fan operation when a sensor detects an abnormal air quality condition.
• The complaint does not explicitly reserve the right to assert dependent claims, but refers generally to "one or more claims." (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

• The complaint accuses unspecified "Exemplary Defendant Products" that are identified in charts incorporated as Exhibit 2. (Compl. ¶11). This exhibit was not publicly filed with the complaint.

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the accused products' specific functionality or market positioning, as all such descriptions are referenced as being within the unprovided Exhibit 2. (Compl. ¶¶ 11, 16).

IV. Analysis of Infringement Allegations

The complaint alleges that Defendant’s products infringe by "practic[ing] the technology claimed by the '178 Patent" and that they "satisfy all elements of the Exemplary '178 Patent Claims." (Compl. ¶16). It incorporates by reference claim charts from Exhibit 2, which is not provided. (Compl. ¶17). A detailed infringement analysis is therefore not possible from the complaint alone.

No probative visual evidence provided in complaint.

Identified Points of Contention

• Scope Questions: As the complaint provides no details about the accused products, it is not possible to identify specific points of contention. A central question for the court will be whether the accused products are used for "retrofitting an existing ventilation system," as required by claim 1, or if they are components of new, fully integrated systems.
• Technical Questions: The complaint does not provide sufficient detail for analysis of potential technical mismatches. A key technical question will be whether the accused products connect to a pre-existing "remote switch terminal" or use a different control interface.

V. Key Claim Terms for Construction

• The Term: "remote switch terminal"
• Context and Importance: This term appears in independent claim 1 and is central to the invention's context of retrofitting an existing system. The infringement analysis will depend on whether the accused products interface with a component that meets this definition. Practitioners may focus on this term because its construction could determine whether the claims read on modern, integrated HVAC controllers that may lack the specific type of simple, two-terminal switch interface described in the patent.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself does not limit the terminal to a specific physical form, referring generally to a "terminal for setting a high speed mode of operation." (’178 Patent, col. 10:4-5). This could support an argument that any input port on a controller that can receive a signal to trigger a high-speed mode qualifies.
  • Evidence for a Narrower Interpretation: The specification repeatedly links this concept to a physical "Remote Switch connection" intended for a manual "wall switch 20." (’178 Patent, col. 2:36, col. 5:9-12). The description that the relay contacts "simulate operation of wall switch 20" could support a narrower construction limited to interfaces designed for simple, electromechanical switches. (’178 Patent, col. 6:41-43).

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials inducing end users and others to use its products in the customary and intended manner that infringes." (Compl. ¶14). The complaint references Exhibit 2 as containing these materials. (Compl. ¶14).
• Willful Infringement: The complaint does not use the term "willful," but it explicitly alleges "Actual Knowledge of Infringement" arising from the service of the complaint and its attached claim charts. (Compl. ¶13). This allegation forms a basis for potential post-filing willful infringement and enhanced damages.

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

Given the limited factual detail in the pleading, the initial phase of the case will likely focus on discovery to resolve foundational questions before substantive claim construction and infringement analysis can occur.

• A primary evidentiary question is what the accused products are and how they operate. The complaint's reliance on an unprovided exhibit leaves the core of the infringement allegation undefined on the public record.
• A core issue will be one of definitional scope: does the claim term "remote switch terminal," which is described in the context of retrofitting older systems with simple wall switch inputs, read on the control interfaces of the accused products, which may be more technologically advanced or part of an integrated system?
• A final question relates to infringement theory: does the plaintiff's case center on the literal act of "retrofitting an existing ventilation system" by end-users as induced by the defendant, or on a direct infringement theory where the defendant's products are alleged to inherently perform the claimed method during testing or installation? The complaint alleges both direct and induced infringement. (Compl. ¶¶ 11, 15).