GSHP Low-GWP Refrigerant Patent Snapshot 2026
This is a small, concentrated niche with 21 patent families in scope, led by Mitsubishi Electric and characterized by a peak-and-decline filing pattern originating around 2017. Japanese industrial filers dominate the technology core while Chinese universities and SMEs hold a meaningful share of secondary activity, and annual filing volume has eased substantially from its earlier peak.
Mitsubishi Electric leads a highly concentrated niche with a steep tier gap
Mitsubishi Electric Corporation holds the top position with 7 patent records, followed by Hokkaido University and Nippon Steel & Sumikin Engineering Co. Ltd., each with 4 patent records. The top five filers together account for 40% of the ranked applicants visible in this query’ combined total, signaling a meaningful concentration at the apex of this field.
The tier gap between the leader and the rest is pronounced: Mitsubishi Electric’s 7 patent records stand clearly above the cluster of second-tier applicants at 3–4 records each, and the majority of ranked applicants hold only 1–2 records. This structure indicates that the core refrigeration-circuit IP is largely controlled by a single industrial player.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Mitsubishi Electric Corporation | 7 | |
| 2 | Hokkaido University | 4 | |
| 3 | NIPPON STEEL & SUMIKIN ENGINEERING CO LTD | 4 | |
| 4 | Earth to Air Systems | 3 | |
| 5 | Hebei University of Technology | 3 | |
| 6 | Shanghai Collodin New Energy Technology Co., Ltd. | 3 | |
| 7 | Shandong Zhongrui New Energy Technology Co., Ltd. | 3 | |
| 8 | Tianjin Yingde Technology Co., Ltd. | 2 | |
| 9 | Denso Corporation | 2 | |
| 10 | Rizhao Ruizhiyuan Technology Business Incubator Co., Ltd. | 1 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Huaneng Henan Clean Energy Co., Ltd. | 1 | |
| 12 | Institute of Mechanics, Chinese Academy of Sciences | 1 | |
| 13 | China University of Geosciences (Wuhan) | 1 | |
| 14 | SHAANXI UNIV OF SCI & TECH | 1 | |
| 15 | Henan Provincial Bureau of Geology and Mineral Resources Exploration — Second Geological Environment Survey Institute | 1 | |
| 16 | Jilin University | 1 | |
| 17 | Hunan University | 1 | |
| 18 | Jiangsu Hezheng Energy Technology Co., Ltd. | 1 | |
| 19 | Get Green Energy Corporation | 1 | |
| 20 | Ningbo University | 1 |
Mitsubishi Electric’s position, anchored exclusively in F25B (refrigeration and heat pumps), suggests that the fundamental refrigerant-circuit patents for ground-source heat pump applications are concentrated in one licensor. New entrants face a narrow but well-defended core technology corridor.
The most recent 18–24 months of filings are subject to publication lag and likely under-represent actual recent activity; the corpus should be treated as a lower bound for current filing rates. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filing activity has eased from a 2017 peak; F25B dominates the technology mix
The annual filing trend reveals a field that peaked in 2017 and has since contracted, while the technology composition shows a visible core in refrigeration-cycle IP with a dispersed set of adjacent application classes.
Annual filing trend
Annual filings peaked at 5 records in 2017 and have trended lower since, with near-zero activity in 2023–2026. The most recent two years remain subject to publication lag, so the true floor of activity may be marginally higher than the chart suggests; nevertheless the directional decline is clear across a multi-year window.
↗ Hover for values · click a bar to ask EurekaTechnology composition
F25B (Refrigeration & heat pumps) is visible in with 46 records, reflecting the refrigerant-circuit focus of the corpus. F24J, F24F (Air conditioning & ventilation), F24T (Geothermal systems), and F24D (Domestic heating systems) form a secondary tier of 7–10 records each, indicating that some applicants are filing across the full heat-pump system stack rather than refrigerant-only claims.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
GEOTHERMISCHES WÄRMEPUMPENSYSTEM UND VERFAHREN ZUR…
A geothermal heat pump system includes a heat pump apparatus, a hot-water heating apparatus, and a controller. The heat pump apparatus includes a compressor, a first heat exchanger configured to exchange heat between water supplied to a load side and refrigerant, an expansion valve, a second heat exchanger configured to exchange heat between the refrigerant… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Geothermal Water Heater | 73 |
| 2 | 一种基于光伏光热的地源热泵耦合系统 | 36 |
| 3 | Performance prediction program and performance pre… | 25 |
| 4 | 一种太阳能复合地源热泵的能量系统及其应用 | 23 |
| 5 | 地埋管及冷却塔地源热泵复合系统的控制系统及方法 | 21 |
| 6 | Geothermal heat pump type water heater | 20 |
| 7 | 一种用于温湿度独立控制空调系统的地源热泵机组 | 19 |
| 8 | Geothermal heat pump | 14 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
Assignee snapshot from the current evidence set
The applicants below are visible in this query result. Because the evidence set is relatively small, read this section as a directional snapshot rather than a full competitive ranking.
Mitsubishi Electric Corporation
Mitsubishi Electric Corporation holds 7 patent records, all concentrated in F25B 1 and F25B 30 (refrigeration and heat pump cycles), with secondary activity in F04B 39 (positive-displacement pumps). This focus on compressor and refrigerant-circuit subclasses indicates a strategy of protecting core system efficiency claims. Applicant momentum data is not available in the evidence for this corpus, so trajectory cannot be quantified further.
families: 7Hokkaido University
Hokkaido University holds 4 patent records, with focus across F25B 30, F24F 11 (air conditioning controls), and F24J 3 (geothermal heat utilization). Its 2-record co-filing partnership with Nippon Steel & Sumikin Engineering Co. Ltd. extends its reach into industrial-scale ground-source systems. As an academic institution, its filings tend to reflect upstream system research rather than product-ready claims, which may offer freedom-to-operate opportunities around its published methods.
families: 4Frequently asked questions
The corpus in scope contains 21 patent families. This is a small, specialist niche; the limited corpus size means individual applicant counts and single filings have a larger proportional effect on rankings and trend readings than in larger technology areas.
Mitsubishi Electric Corporation is the top filer with 7 patent records, all concentrated in refrigeration and heat pump cycle subclasses (F25B 1 and F25B 30). This represents roughly one-third of the entire corpus for a single applicant.
Annual filing volume peaked in 2017 at 5 records and has eased substantially since, with near-zero activity in 2023 and 2024. The lifecycle is classified as Decline. The most recent 18–24 months remain subject to publication lag, so the current floor is uncertain, but the multi-year directional trend is clearly downward.
China leads with 28 patent records, followed by Japan with 7 and Europe (EPO) with 4. The United States and Australia each hold 2 records, and WIPO (PCT) accounts for 2 records. The China-heavy distribution reflects the large number of Chinese university and SME applicants in the ranking.
Two active co-filing pairs are documented: Hokkaido University and Nippon Steel & Sumikin Engineering Co. Ltd. co-filed 2 records, linking academic geothermal research with industrial engineering. Hebei University of Technology and Tianjin Yingde Technology also co-filed 2 records, representing a Chinese university-SME collaboration.
F24T (Geothermal systems) and F24D (Domestic heating systems) each hold fewer than 8 patent records within this corpus, despite being central application domains for ground-source heat pumps. F24H (Fluid heaters and water heaters) and H02J (Power supply and grid systems) each hold only 3 records, making them additional adjacent branches with relatively sparse prior art in this specific technology intersection.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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