IP Law Daily, PATENT—D. Ariz.: Venue proper in infringement lawsuit between HVAC companies, (Aug 4, 2025)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

District court finds Arizona-based sales representatives’ home offices satisfy the Cray factors under 28 U.S.C. § 1400(b).

The federal district court in Phoenix, Arizona, rejected a motion by Fieldpiece Instruments, Inc. to dismiss a patent infringement suit brought by Evergreen Telemetry LLC for improper venue. The court ruled that Fieldpiece maintained a "regular and established place of business" in Arizona through its Arizona-based employees, whose homes functioned as operational bases. Applying In re Cray Inc., 871 F.3d 1355 (Fed. Cir. 2017), the court found that all three statutory criteria under 28 U.S.C. § 1400(b) were met, allowing the case to proceed (Evergreen Telemetry LLC v. Fieldpiece Instruments Inc., No. 2:24-cv-02814-SPL (D. Ariz. Aug. 1, 2025)).

Background. The plaintiff, Evergreen Telemetry LLC, is based in Arizona. It develops wireless tools and systems for the heating, ventilation, and air-conditioning (HVAC) industry. The company filed suit in its home district against the defendant, Fieldpiece Instruments, Inc., a Delaware corporation headquartered in Orange, California. Fieldpiece manufactures and sells wireless HVAC diagnostic systems that directly compete with Evergreen’s technology.

In this lawsuit, Evergreen alleged infringement of three patents covering wireless HVAC diagnostic technologies: U.S. Patent Nos. 9,605,857 (the ’857 patent), 10,830,466 (the ’466 patent), and 11,441,798 (the ’798 patent). These patents relate to systems and methods for wirelessly monitoring, testing, and transmitting data in HVAC applications.

Evergreen filed the infringement suit on October 17, 2024, in the District of Arizona, asserting violations of 35 U.S.C. § 271(a)–(c). On April 9, 2025, Fieldpiece moved to dismiss the case under Federal Rule of Civil Procedure 12(b)(3), arguing that it was not “resident” in Arizona and did not maintain a “regular and established place of business” as required by § 1400(b). Evergreen countered that Fieldpiece had employed at least one Arizona-based sales representative since 2022, who conducted regular business activities from a home office, stored inventory, and operated a company-branded vehicle.

Physical place requirement. The court first assessed whether Fieldpiece had a “physical place” of business in the district. Relying on Cray and distinguishing Herbert v. Diagnostic Prods. Corp., No. 85 Civ. 0856, 1986 WL 6781 (S.D.N.Y. June 10, 1986), the court found that a home office could qualify if business activity was sufficiently linked to that location. The court considered that Fieldpiece shipped merchandise and promotional material to employees’ homes for use in field demonstrations, akin to the scenario in RegenLab USA LLC v. Estar Techs. Ltd., 335 F. Supp. 3d 526 (S.D.N.Y. 2018). The home was not merely a place of residence, but a functional locus for marketing and logistical activity.

Regular place of business. Turning to whether the business was “regular and established,” the court cited Phillips v. Baker, 121 F.2d 752 (9th Cir. 1941), and IOT Innovations LLC v. Monitronics Int’l, Inc., No. 2:22-CV-0432-JRG-RSP, 2023 WL 6318049 (E.D. Tex. September 11, 2023). It found that Fieldpiece's activities in Arizona—sales, distributor support, technician training—were methodical and ongoing. The company had consistently employed an Arizona-based representative since 2022 and serviced more than 100 distributor locations statewide, establishing a long-term business presence that satisfied the Cray criteria.

Place of the defendant. Fieldpiece argued that the sales representatives’ homes were merely private residences and not “places of the defendant,” citing the absence of any lease, ownership interest, or signage. The court disagreed, emphasizing that Fieldpiece had posted job listings explicitly requiring candidates to reside in the Phoenix metro area and provided branded vehicles and sales kits to be stored at home. The court distinguished Cray, where the employer had no such ongoing operational ties to the district. Instead, it found support in In re Cordis Corp., 769 F.2d 733 (Fed. Cir. 1985), noting that the home-based operations were sufficiently connected to Fieldpiece’s business objectives to qualify as its place of business.

Conclusion. Thus, the court concluded that no single fact was dispositive but that the “totality of the circumstances” established that Fieldpiece’s Arizona-based operations satisfied the three-part test under § 1400(b). Accordingly, the court denied Fieldpiece’s motion to dismiss, holding venue proper in the District of Arizona.

The Case is No. 2:24-cv-02814-SPL.

Judge: Logan, S.

Attorneys: Christine N. Jones (Newman Jones PLLC) for Evergreen Telemetry LLC. Eric Michael Fraser (Osborn Maledon PA) for Fieldpiece Instruments Inc.

Companies: Evergreen Telemetry LLC; Fieldpiece Instruments Inc.

Cases: Patent ArizonaNews