DCT
6:24-cv-00152
Green Revolution Cooling Inc v. Riot Platforms Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Green Revolution Cooling, Inc. (Delaware)
- Defendant: Riot Platforms, Inc. (Nevada)
- Plaintiff’s Counsel: Michelman & Robinson, LLP
- Case Identification: 6:24-cv-152, W.D. Tex., 07/15/2024
- Venue Allegations: Plaintiff alleges venue is proper based on Defendant operating a "regular and established place of business" within the district, specifically its large-scale immersion cooling facility in Rockdale, Texas.
- Core Dispute: Plaintiff alleges that Defendant’s industrial-scale Bitcoin mining operations, which use immersion cooling technology, infringe two patents related to systems and apparatuses for cooling servers by submersion in a dielectric fluid.
- Technical Context: The technology at issue is single-phase immersion cooling for high-density computing hardware, an alternative to traditional air cooling that offers potentially greater thermal efficiency and power density for data centers.
- Key Procedural History: The complaint alleges that Defendant’s supplier of immersion cooling systems, Midas, has been aware of Plaintiff’s patent portfolio since at least 2016 through its own patent prosecution history and since 2022 through separate litigation, raising questions about Defendant's potential pre-suit knowledge.
Case Timeline
| Date | Event |
|---|---|
| 2008-08-11 | Earliest Priority Date for ’914 and ’463 Patents |
| 2018-06-05 | U.S. Patent No. 9,992,914 Issues |
| 2018-11-06 | U.S. Patent No. 10,123,463 Issues |
| 2021-10-19 | Riot Announces Use of Immersion-Cooling Technology |
| 2022-05-01 | Riot’s First Immersion-Cooled Building Comes Online |
| 2024-07-15 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,992,914 - "Commonly Submersed Servers with Velocity Augmentation and Partial Recirculation in Tank", Issued June 5, 2018
The Invention Explained
- Problem Addressed: The patent describes the inefficiency of conventional air cooling in data centers, which consumes significant electricity and struggles to manage the heat generated by densely packed, high-performance servers, thereby limiting data center design and increasing operational costs (Compl. ¶33-34; ’914 Patent, col. 1:31-38, 2:46-55).
- The Patented Solution: The invention proposes an apparatus where multiple rack-mountable servers are submerged in a tank containing a dielectric liquid coolant. A system of pumps and an external heat exchanger circulates the coolant to remove heat from the servers. The patent describes placing servers in a vertical orientation to facilitate easy installation and removal without disturbing other operating servers within the same tank (Compl. ¶36; ’914 Patent, col. 14:46-52).
- Technical Importance: This liquid immersion approach is presented as a solution to cool much higher heat densities—over 1,200 Watts-per-square-foot compared to 150 Watts-per-square-foot for some air-cooled systems—thereby enabling more powerful and compact data center configurations while reducing energy consumption (Compl. ¶34; ’914 Patent, col. 3:8-14).
Key Claims at a Glance
- The complaint asserts infringement of independent claim 15.
- The essential elements of independent claim 15 include:
- An apparatus for holding and cooling rack-mountable servers.
- A tank defining an open interior volume with a coolant inlet and outlet.
- One or more mounting members configured to hold servers in a horizontally stacked relationship and in a vertical orientation.
- A volume of dielectric liquid coolant.
- A controller configured to maintain the coolant temperature in the range of about 90° F to 130° F.
- A liquid-to-liquid or liquid-to-refrigerant heat exchanger located outside the tank.
- The volume of dielectric liquid coolant is thermally coupled to a distal location via the heat exchanger.
- The complaint reserves the right to assert dependent claims 16-21 (Compl. ¶55).
U.S. Patent No. 10,123,463 - "Liquid Submerged, Horizontal Computer Server Rack and Systems and Method of Cooling such a Server Rack", Issued November 6, 2018
The Invention Explained
- Problem Addressed: As a parent to the ’914 Patent and sharing the same specification, the ’463 Patent addresses the same technical problem of inefficient and power-intensive air cooling for data centers (Compl. ¶70; ’463 Patent, col. 1:28-38).
- The Patented Solution: The invention is an apparatus for cooling servers by immersing them in a dielectric coolant within an open-topped tank. The claims focus on a specific physical arrangement: servers are held by mounting members in a vertical orientation, stacked horizontally, such that one of their two smallest sides faces upward. This configuration is intended to facilitate access and maintenance while enabling efficient cooling through a multi-circuit fluid apparatus (Compl. ¶74; ’463 Patent, col. 25:48-67).
- Technical Importance: The technology provides a framework for designing high-density, liquid-cooled data centers that are more energy-efficient than their air-cooled counterparts, addressing a key challenge in large-scale computing ('463 Patent, col. 3:9-15).
Key Claims at a Glance
- The complaint asserts infringement of independent claims 1, 18, 22, and 25.
- The essential elements of independent claim 1 include:
- An apparatus for cooling a plurality of rack-mountable servers.
- At least one tank with an open or openable top sized to receive at least one row of servers.
- One or more mounting members holding at least two servers in a horizontally stacked relationship and a vertical orientation, where one of the two smallest sides faces upward and the motherboard is vertically oriented.
- At least two of the servers are independently operable and configured to connect to a computer network.
- A volume of dielectric coolant at least partially held in the tank.
- A multi-circuit fluid cooling apparatus.
- The complaint reserves the right to assert dependent claims 2, 4-8, 10, 12-14, 18-27, and 29 (Compl. ¶92).
III. The Accused Instrumentality
- Product Identification: The accused instrumentalities are the immersion cooling systems used at Defendant Riot Platforms' Bitcoin mining facilities in Rockdale and Corsicana, Texas (Compl. ¶39).
- Functionality and Market Context: The accused systems are used to cool high-power Application-Specific Integrated Circuit (ASIC) miners by submerging them in large, open-topped tanks filled with a specialized, non-conductive fluid (Compl. ¶39, ¶42). This fluid is circulated by pumps to external heat exchangers to dissipate the significant heat generated by the mining hardware, after which the cooled fluid is returned to the tanks (Compl. ¶41, ¶44, ¶46). The complaint alleges that Riot's Rockdale Facility is the "largest single Bitcoin mining facility in North America" and that Riot derives hundreds of millions of dollars in revenue from its mining operations, which rely on this cooling technology (Compl. ¶10, ¶24). One of the complaint's visual exhibits shows rows of large, open-topped immersion tanks used in the accused facilities (Compl. p. 16).
IV. Analysis of Infringement Allegations
’914 Patent Infringement Allegations
| Claim Element (from Independent Claim 15) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a tank defining an open interior volume and having a coolant inlet for receiving a dielectric liquid coolant... and a coolant outlet | The accused systems use open-top tanks with inlets for receiving cooled fluid and outlets for removing heated fluid, which are fluidly coupled. | ¶40 | col. 10:9-11 |
| one or more mounting members positioned within the interior volume and configured to hold a plurality of rack-mountable servers in a horizontally stacked relationship... with the rack-mountable servers in a vertical orientation | Mounting brackets within the tanks allegedly hold the ASIC miners vertically and stacked side-by-side in a horizontal row. | ¶43 | col. 14:46-52 |
| a controller configured to maintain a temperature of the dielectric liquid coolant in the range of about 90° F. to about 130° F. | A server purchase agreement allegedly requires Riot's infrastructure to operate miners within a specific liquid temperature range, which Plaintiff alleges on information and belief is approximately 90° F to 130° F. | ¶45 | col. 26:48-51 |
| a liquid-to-liquid or liquid-to-refrigerant heat exchanger outside of the tank... thermally coupled to a distal location | Press releases and videos allegedly show the use of a "secondary heat exchanger" located outside the immersion tanks, to which heated fluid is pumped for cooling. | ¶46-47 | col. 10:23-28 |
- Identified Points of Contention:
- Scope Question: A potential dispute may arise over whether a specialized Bitcoin mining ASIC qualifies as a "rack-mountable server" within the meaning of the patent, which was filed in the context of general-purpose IT data centers.
- Evidentiary Question: The allegation for the "controller" limitation relies on an "information and belief" interpretation of a redacted temperature range in a third-party agreement. The case may require evidence showing not just that the system operates within this range, but that it is actively "configured to maintain" it as claimed. The complaint includes a video still of a worker installing a miner, which is used to support the claim of vertical orientation and independent removability (Compl. p. 19).
’463 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| at least one tank... an open or openable top sized to receive at least one row comprising a plurality of rack mountable servers | The accused systems use open-top tanks sized to receive multiple rows of ASIC miners, which are alleged to be rack-mountable servers. | ¶72 | col. 14:35-40 |
| one or more mounting members... configured to hold... servers in a horizontally stacked relationship... with the rack-mountable servers in a vertical orientation such that one of the two smallest sides of the rack-mountable server faces upward | Videos allegedly show servers mounted vertically in a side-by-side arrangement where their narrowest upward-facing side is exposed, consistent with the claim's orientation requirement. | ¶74 | col. 14:50-57 |
| at least two of the rack-mountable servers are independently operable... and configured to connect to a computer network | The ASIC miners are alleged to be independently operable and configured to connect to the Bitcoin mining network. | ¶75 | col. 8:36-50 |
| a multi-circuit fluid cooling apparatus | The complete system, including the tanks, pumps, coolant, and external heat exchangers, is alleged to form the claimed multi-circuit apparatus. | ¶77-78 | col. 4:30-49 |
- Identified Points of Contention:
- Technical Question: The claim requires a specific physical arrangement where "one of the two smallest sides" of the server faces upward. The infringement analysis will depend on whether the physical dimensions and orientation of the accused ASIC miners meet this precise geometric limitation. The complaint provides a close-up visual of the miners in the tank to support this allegation (Compl. p. 32).
- Scope Question: The construction of "multi-circuit fluid cooling apparatus" may be a point of contention, as it is a broad term whose scope will need to be defined by the intrinsic evidence of the patent.
V. Key Claim Terms for Construction
The Term: "rack-mountable server" (asserted in claims of both patents)
- Context and Importance: This term is critical because the accused devices are Bitcoin mining ASICs, not traditional IT servers. The defense may argue that an ASIC is not a "server" or is not "rack-mountable" in the manner contemplated by the patent, potentially avoiding infringement entirely.
- Intrinsic Evidence for a Broader Interpretation: The specification provides a broad definition of "server" as a "computing device connected to a computing network" and refers generally to cooling "computing devices having heat-generating electronic components" (Compl. ¶36, citing ’914 Patent, col. 4:30-33; ’914 Patent, col. 8:28-35).
- Intrinsic Evidence for a Narrower Interpretation: The patent’s illustrations, such as Figure 12A, depict conventional, general-purpose servers. A party could argue that the term should be limited to the types of devices explicitly shown and described in the embodiments ('914 Patent, Fig. 12A).
The Term: "controller configured to maintain a temperature ... in the range of about 90° F. to about 130° F." (’914 Patent, Claim 15)
- Context and Importance: Infringement of the ’914 Patent's independent claim hinges on this specific, narrow temperature range. Practitioners may focus on this term because the complaint's evidence for it is indirect and based on "information and belief." The dispute will likely center on whether the accused system is purposefully "configured to maintain" this range or merely operates within it incidentally.
- Intrinsic Evidence for a Broader Interpretation: The patent's objective is to operate at an "elevated temperature" to improve thermodynamic efficiency, and this range could be seen as one example of that broader principle ('914 Patent, col. 10:50-54).
- Intrinsic Evidence for a Narrower Interpretation: The specification describes a controller that actively manages the system by "output[ting] signals to the pump ... to adjust the flow of the liquid coolant" and reject heat, suggesting that "configured to maintain" implies active, targeted control rather than passive operation ('914 Patent, col. 10:60-66).
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement of infringement under 35 U.S.C. § 271(b). The factual basis alleged is that Riot provides "operating and maintenance services to third-party mining companies" who use the accused systems and provides "directions, designs, and/or instructions to suppliers" to manufacture the infringing components (Compl. ¶57, ¶94).
- Willful Infringement: Willfulness is alleged based on purported pre-suit knowledge of the patents. The complaint claims that Riot's primary supplier, Midas, was aware of Plaintiff's patent portfolio from separate litigation and its own patent prosecution history, and alleges this knowledge can be imputed to Riot. It further alleges that Riot had direct discussions with a "GRC partner" about using Plaintiff's systems before selecting Midas (Compl. ¶58, ¶95).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "rack-mountable server," rooted in the patent’s context of general-purpose IT hardware, be construed to cover the specialized ASIC miners used in the accused large-scale cryptocurrency mining facilities?
- A key evidentiary question will be one of functional proof: does the evidence show the accused product's control system is specifically "configured to maintain" the narrow 90-130°F temperature range required by Claim 15 of the ’914 Patent, or does it merely operate incidentally within that range?
- The viability of the willfulness and inducement claims may depend on a question of imputed knowledge: can Plaintiff demonstrate that Riot possessed the requisite pre-suit knowledge of the asserted patents based on the alleged knowledge of its third-party component supplier and alleged discussions with an unnamed partner?