HFO Refrigerant Patents: Leaders, Trends & White Space 2026
A patent landscape of hydrofluoroolefin (HFO) low-GWP refrigerants: 703 records analysed for filing trends, leading assignees, IPC composition and open claim space, drawing on Patsnap Eureka data through 2026.
Filing growth = 2021 (15 records) → 2024 (42); 2024 is the last year we treat as complete. Top-5 share = the 5 largest assignees ÷ all 703 records in scope (CR5), not the ranked leaders only.
Why HFO refrigerant filings look the way they do
Hydrofluoroolefins (HFOs) emerged as the leading replacement chemistry once HFCs came under phase-down schedules, and patent activity in this dataset traces that shift directly: refrigerant composition claims (C09K) and refrigeration-cycle hardware claims (F25B) together dominate the corpus, while narrower branches — vehicle A/C, air-conditioning systems, lubricant chemistry — carry meaningfully fewer filings. The 703 records in scope span 2015 through the 2026 cut-off, so the field is still actively defining itself rather than settling into a mature, low-activity phase.
Filing behaviour is bimodal: an early peak in 2017 reflects the first wave of composition claims as HFO blends were being defined, and a second, steeper rise from 2021 to 2024 reflects hardware and system-level claims catching up as commercial deployment accelerated. Because publication lags filing by roughly eighteen months, the most recent one to two years in the trend understate real filing activity and should not be read as a slowdown.
Let an AI agent run this analysis on your own technology
Pick a task. Every answer cites the patents behind it.
Filing trends and technology composition
The figures below are drawn directly from the 703 records in scope, spanning filings from 2015 through the 2026 data cut-off across the receiving offices in this corpus.
A two-wave filing pattern
The peak filing year on record is 2017 at 52 published families, tied to the first generation of HFO composition claims. Activity then rebuilt sharply: filings rose from 15 in 2021 to 42 in 2024, a 180% increase over that three-year span, before the 2025-2026 figures — still incomplete due to publication lag — taper off in the raw count.
Publication lags filing by roughly 18 months, so 2025 onwards are still filling in. Growth rates on this page therefore end at 2024; running them to the last bar would understate the field.
Composition and hardware claims dominate
C09K (materials for miscellaneous applications) covers 54.5% of the 703 records and F25B (refrigeration and heat pumps) covers 47.8%, confirming that most filings are still anchored in refrigerant chemistry and cycle hardware rather than end-use integration. Lubricant-related classes C10M and C10N sit at 25.7% and 11.4% respectively, and vehicle and building air-conditioning classes (B60H, F24F) sit under 5% each — smaller, more specialised pockets of the same corpus.
Shares are the percentage of the 703 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Low-GWP Refrigerants: Hydrofluoroolefin Refrigerant Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about low-gwp refrigerants: hydrofluoroolefin refrigerant patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art and a representative filing
US20190203091A1 — Lower GWP refrigerant compositions (Trane International)
The application claims a non-flammable HVACR refrigerant composition combining R134a, a hydrofluorocarbon refrigerant with GWP below 150 or a hydrofluoroolefin refrigerant, and CF3I, together with methods of making and retrofitting such compositions in existing systems.Filed 2019-07-04 by Trane International. Retrofit-oriented claims of this kind are a recurring pattern across the corpus, since they let incumbents target existing HVACR installed base rather than new-build systems only.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | WO2009151669A1 | Halogenated alkene heat transfer compositions with improved oil return | 84 |
| 2 | WO2010077898A2 | Trans-chloro-3,3,3-trifluoropropene for use in chiller applications | 67 |
| 3 | US20110041529A1 | Compositions of hydrochlorofluoroolefins | 62 |
| 4 | WO2009140231A2 | Compositions of hydrochlorofluoroolefins | 58 |
| 5 | WO2018235832A1 | Heat transfer system | 55 |
| 6 | US20110012052A1 | Halogenated alkene heat transfer composition with improved oil return | 50 |
| 7 | US8454853B2 | Halogenated alkene heat transfer composition with improved oil return | 42 |
| 8 | US20120117990A1 | Heat transfer process | 41 |
| 9 | US20110155359A1 | Hollow structures and associated method for conveying refrigerant fluids | 37 |
| 10 | WO2011091404A1 | Heat transfer composition of oxygenated lubricant with hydrofluoroolefin and hydrochlorofluoroolefin refriger… | 36 |
Citation counts favour older filings simply because they have had longer to accumulate citations inside this corpus; treat them as a signal of influence on subsequent filers, not as a measure of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the numbers mean for a filing decision
Three patterns recur across the assignee ranking, the trend line and the class breakdown, and each has a direct bearing on where new claims are likely to survive prosecution.
The top of the field is dense, not narrow
The five leading assignees account for 46.4% of all 703 records in scope, and the ranked ten reach 64.3%. That level of concentration among named chemical and equipment majors means core composition and cycle claims sit on layered prior art; freedom-to-operate work for those branches needs to start with the leaders' portfolios, not a general prior-art sweep.
Momentum has rebuilt since 2021, not faded
Filings grew from 15 in 2021 to 42 in 2024, a 180% rise over three years, even though the single highest year on record remains 2017 at 52. That earlier peak reflects first-generation composition filings; the more recent rise looks more like hardware and system integration catching up to a chemistry that was already defined.
Core chemistry is crowded; vehicle A/C is thin
C09K materials claims cover 54.5% of the 703 records and F25B cycle claims cover 47.8%, while B60H vehicle heating and air-conditioning claims sit at just 4.1%. Applicants targeting mobile air-conditioning integration are filing into a comparatively open branch relative to the core refrigerant chemistry classes.
Joint filings cluster around a small number of corporate groups
Only ten co-assignee pairs appear in the corpus, and the strongest links sit inside single corporate groups rather than across competitors. That pattern points to internal group filing practice rather than a broad web of industry co-development.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to low-gwp refrigerants: hydrofluoroolefin refrigerant patent landscape, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| SK Innovation Co., Ltd. | SK ENMOVE CO LTD | 15 |
| Daikin Industries, Ltd. | Daikin Applied Americas Inc. | 9 |
| SK Innovation Co., Ltd. | SK Energy Co., Ltd. | 7 |
| Arkema Inc. | VAN HORN BRETT L | 6 |
| Panasonic Corporation (Japan) | SATO SHIGEHIRO | 4 |
| Panasonic Corporation (Japan) | NAKANO MASAO | 4 |
| Panasonic Corporation (Japan) | KARINO TSUYOSHI | 4 |
| Panasonic Corporation (Japan) | IIDA NOBORU | 4 |
The strongest co-assignee links in this dataset connect subsidiaries of the same corporate group, which is a normal artefact of how large groups file jointly across affiliated entities rather than evidence of broader industry collaboration.
Where to take this analysis
The figures on this page describe the shape of the field; deciding where a specific composition or system claim fits inside it takes a closer read of the leaders' claim sets and the branches they have left thin.
Map freedom-to-operate against the leaders
Run the five leading assignees' active families against a specific refrigerant blend or hardware configuration before drafting, since they hold nearly half of all records in scope.
Explore assignee portfolios in EurekaTrack the post-2024 filing wave as it publishes
The 2025-2026 counts in this dataset are still filling in under normal publication lag; revisit the trend once those years mature rather than treating the current dip as a slowdown.
Set up trend monitoring in EurekaProbe the thinner IPC branches
Vehicle air-conditioning and lubricant-property claims carry a fraction of the filings that core composition and cycle classes do, which is where a narrower, well-drafted claim has more room to stand.
Search white space in EurekaCommon questions on HFO refrigerant patents
The assignee ranking in this dataset covers 100 companies across 703 records, and it is genuinely top-heavy: the five leading assignees together hold 46.4% of all records, and the ranked ten reach 64.3%. The leader alone accounts for 105 records, well ahead of the fifth-place assignee at 28 and tenth place at 21. That gap between the top handful and everyone else means a small number of chemical and equipment manufacturers set the pace for composition and system claims, while a long tail of other filers holds far smaller, more specialised positions.
Filings rose from 15 in 2021 to 42 in 2024, a 180% increase over that three-year span, following an earlier peak of 52 in 2017. The 2017 peak lines up with first-generation composition and blend claims as HFO chemistry was being established; the 2021-2024 rise looks more like hardware, cycle and system-integration claims catching up to a chemistry base that regulation had already made commercially urgent. Because publication lags filing by roughly eighteen months, the apparent tapering in 2025-2026 in the raw counts is an artefact of that lag, not a real drop in activity.
Two IPC subclasses dominate: C09K, covering materials for miscellaneous applications including refrigerant compositions, appears on 54.5% of the 703 records, and F25B, covering refrigeration and heat-pump cycles, appears on 47.8%. Lubricant compatibility classes C10M and C10N follow at 25.7% and 11.4% respectively, since HFO blends often require reformulated lubricants. Vehicle air-conditioning (B60H) and general air-conditioning and ventilation (F24F) sit under 5% each, marking them as narrower, less contested branches of the same field.
The Trane International application claims a non-flammable HVACR refrigerant composition built from R134a, a hydrofluorocarbon with GWP under 150 or a hydrofluoroolefin refrigerant, and CF3I, plus methods of making and retrofitting that composition into existing systems. It does not block HFO-only blends that omit R134a and CF3I, since the claimed composition is specifically anchored to that three-component combination. Anyone designing a refrigerant blend should check the specific component ratios and the retrofit method claims closely rather than assuming any HFO-containing blend is covered.
The class breakdown points to vehicle air-conditioning (B60H, 4.1% of records) and general air-conditioning and ventilation systems (F24F, 3.4%) as the thinnest branches relative to the dominant materials and cycle classes. Lubricant-property claims (C10N, 11.4%) are also comparatively underclaimed against the core composition space. A first claim in these branches is more likely to face a shallower prior-art landscape than a new refrigerant composition claim filed directly against the crowded C09K and F25B classes.
Research Low-GWP Refrigerants: Hydrofluoroolefin Refrigerant Patent Landscape in depth with Eureka
Go past this page: query the whole low-gwp refrigerants: hydrofluoroolefin refrigerant patent landscape corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.