CO2 (R744) Heat Pump Patent Landscape 2026
The CO2 (R744) heat pump patent field is heavily concentrated in Chinese academic institutions, with Xi’an Jiaotong University alone holding the leading position and China accounting for the dominant share of jurisdictional coverage. Activity peaked around 2019 and has since eased, signaling a maturing but still active research base with selective opportunities in adjacent application areas.
Xi’an Jiaotong University leads a China-centric, academically driven field
Xi’an Jiaotong University holds the top position with 22 patent records, followed by Tianjin University of Commerce with 12 patent records — together representing a significant concentration at the top of the ranking.
The top five filers account for 35% of the combined output of the hundred largest filers, indicating a moderately concentrated field where a small cluster of academic institutions and a few commercial players dominate activity. A clear tier gap separates the top two from the rest, who each hold four records or fewer.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Xi’an Jiaotong University | 22 | |
| 2 | Tianjin University of Commerce | 12 | |
| 3 | Ningbo Saisen Energy Saving Equipment Co., Ltd. | 4 | |
| 4 | Carrier Corporation | 4 | |
| 5 | Foshan Lingyingda Energy Saving Technology Co., Ltd. | 4 | |
| 6 | Shanghai Ocean University | 3 | |
| 7 | Beijing China Academy of Railway Sciences Cars Energy Sciences Institute | 2 | |
| 8 | UNIV OF SHANGHAI FOR SCI & TECH | 2 | |
| 9 | Gansu Yide New Energy Equipment Co., Ltd. | 2 | |
| 10 | PetroChina Co., Ltd. | 2 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Harbin Institute of Technology | 2 | |
| 12 | ENERGY SAVING & ENVIRONMENTAL PROTECTION & OCCUPAT… | 2 | |
| 13 | PetroChina Shenzhen New Energy Research Institute Co., Ltd. | 2 | |
| 14 | Midea Group Co., Ltd. | 2 | |
| 15 | Zhongke Carbonleng (Wuxi) High-Tech Co., Ltd. | 2 | |
| 16 | GD MIDEA HEATING & VENTILATING EQUIP CO LTD | 2 | |
| 17 | Sadigh Tehrani Shahin | 2 | |
| 18 | Shandong Chaoyue Diyuan Thermal Pump Technology Co., Ltd. | 2 | |
| 19 | China Academy of Railway Sciences Corporation Ltd. | 2 | |
| 20 | Shandong Meilinda Renewable Energy Development Co., Ltd. | 2 |
The dominance of universities at the top implies that foundational and system-level R&D remains largely in academic hands, leaving commercial players — notably Carrier Corporation and Midea Group — with comparatively modest footprints and potential room to consolidate IP positions.
The most recent 18–24 months of filings are likely under-counted due to standard patent publication lag; apparent low volumes in 2024–2025 should not be read as definitive evidence of further decline. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Filing activity peaked in 2019 and technology focus remains anchored in core refrigeration IPC classes
The annual filing trend reveals a clear surge around 2019 followed by a moderation in subsequent years. The technology composition chart shows that the corpus is heavily weighted toward core refrigeration and heat pump classes, with a long tail of adjacent application branches.
Annual filing trend
Filings climbed from 6 records in 2017 to a peak of 15 in 2019, then moderated into a range of 6–13 through 2023. The 2024 and 2025 figures should be treated as provisional given publication lag — the apparent plateau does not confirm a sustained decline.
↗ Hover for values · click a bar to ask EurekaTechnology composition
F25B (Refrigeration and heat pumps) is the dominant IPC branch by a wide margin, reflecting the core thermodynamic system focus of most filings. F24D (Domestic heating systems) and F24H (Fluid heaters and water heaters) form a secondary cluster, pointing to residential and commercial heating integration. Smaller branches — including food preservation, drying, and vehicle HVAC — indicate selective but limited diversification into application-specific use cases.
↗ 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.
Precooler-based transcritical co2 heat pump system…
The present disclosures discloses a precooler-based transcritical CO<sub>2 </sub>heat pump system and a control method of a waterway two-way valve thereof, in which a transcritical CO<sub>2 </sub>heat pump system is assisted by a precooler system. A circulating waterway is divided into two parts in the system through a three-way diversion valve and a… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | 一种适于接暖气片的空气源CO2热泵系统 | 22 |
| 2 | 一种跨临界CO2复合热泵系统 | 21 |
| 3 | 一种带有快速除霜功能的跨临界CO2热泵供暖系统 | 20 |
| 4 | Heat pump with intercooler | 20 |
| 5 | 一种暖气片供暖用跨临界CO2热泵系统 | 19 |
| 6 | 一种适用于寒冷地区的补气增焓CO<sub>2</sub>部分复叠热泵 | 15 |
| 7 | 一种跨临界CO<sub>2</sub>复合热泵及其控制方法 | 14 |
| 8 | Heat pump with intercooler | 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.
What the competitive structure means for R&D investment decisions
The CO2 heat pump landscape combines a declining lifecycle signal with strong academic concentration, limited cross-border filings, and identifiable gaps in adjacent application domains. Each factor carries distinct implications for where new IP investment is most defensible.
Post-peak field with easing annual volume
The lifecycle stage is classified as Decline, with annual filings easing back from the 2019 peak. This suggests core transcritical CO2 heat pump system architectures are increasingly well-covered, making incremental system-level patents harder to defend. R&D investment is better directed toward application-specific differentiation or integration with adjacent technologies such as solar collectors or AI-based control, where coverage remains sparse.
Lifecycle: DecliningTwo academic leaders, limited commercial depth
The top five filers hold 35% of the output among the hundred largest filers, and the top two — Xi’an Jiaotong University and Tianjin University of Commerce — are both Chinese academic institutions. Commercial entities such as Carrier Corporation, Midea Group, and Ningbo Saisen each hold only 4 or fewer patent records. This creates a landscape where commercial players could acquire or license foundational academic IP rather than building from scratch, or target under-served application niches to establish proprietary positions.
Concentration: Moderate-HighMinimal co-filing activity identified; Midea entities are the primary co-filers
Only two co-applicant relationships are recorded in the evidence: Midea Group and GD Midea Heating & Ventilating Equipment jointly filed on 2 occasions, and Xi’an Jiaotong University co-filed once with the State Grid Shaanxi Electric Power Research Institute. This low collaboration density suggests the field operates largely through independent institutional programs, with the Midea group pairing being the only visible commercial-scale coordination.
Collaboration: LowChina dominates; meaningful white space in Western jurisdictions
China accounts for 93 patent records, making it the near-exclusive filing jurisdiction. The United States registers 7 records, WIPO (PCT) 3, and Europe (EPO) only 2. Japan and South Korea — major heat pump manufacturing markets — each have only 2 records. This concentration means that CO2 heat pump innovations are largely unprotected outside China, and commercial entrants targeting European or North American markets face relatively low prior-art density from this corpus.
Geography: China-CentricGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| Midea Group Co., Ltd. | GD Midea Heating & Ventilating Equipment Co., Ltd. | 2 |
| Xi’an Jiaotong University | State Grid Shaanxi Electric Power Co., Ltd. Electric Power Research Institute | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
Xi’an Jiaotong University and Tianjin University of Commerce anchor the field; Carrier is the leading commercial entrant
The top two positions are held by Chinese research universities with deep focus on core F25B refrigeration and heat pump subclasses. Commercial players occupy a distinct lower tier, with Carrier Corporation representing the most significant non-Chinese, non-academic presence.
Xi’an Jiaotong University
Xi’an Jiaotong University leads with 22 patent records, focused primarily on F25B subclasses covering refrigeration cycles, expansion devices, and system control — reflecting broad foundational coverage of transcritical CO2 heat pump architectures. Momentum data classifies the institution as a new entrant in the recent window with 6 recent records, suggesting sustained and active output rather than historical accumulation alone.
families: 22Carrier Corporation
Carrier Corporation holds 4 patent records and is the highest-ranked non-Chinese, non-academic applicant in the corpus. Its technology focus spans F25B subclasses covering compression cycles, heat pump configurations, and combined heating-cooling systems — a more applied, product-oriented profile compared to the university leaders. As a global HVAC manufacturer, Carrier’s modest record count in this corpus may reflect a strategy of filing primarily outside China, where the evidence shows very limited coverage.
families: 4| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Xi’an Jiaotong University | 6 | ▲ new entrant |
| Foshan Lingyingda Energy Saving Technology Co., Ltd. | 2 | ▲ new entrant |
| Shanghai Ocean University | 1 | ▲ new entrant |
Under-served application branches adjacent to the core CO2 heat pump corpus
Several IPC branches appear alongside the dominant F25B core with low record counts, indicating areas where CO2 heat pump technology intersects with specific end-use applications but has not yet attracted concentrated IP activity. These are observations of relative sparsity; entry-path viability depends on market and regulatory context.
F24H · Fluid heaters and water heaters
With 16 patent records and an 8% share of the branch distribution, F24H represents the most populated adjacent branch — yet it remains well below the F25B core. CO2 heat pump water heaters (e.g., CO2 heat pump water heaters for residential and commercial hot water supply) are a commercially established product category, particularly in Japan and Europe. The low filing count in this corpus, combined with near-absent EPO and Japanese filings, suggests that Western market IP positions in this segment are not well-covered by the applicants identified here, making it a plausible area for targeted filing by commercial entrants with product ambitions in those markets.
Search this in Eureka →A23B / A23L · Food preservation and processing
Food preservation (A23B, 4 records) and food and beverage processing (A23L, 5 records) together account for approximately 4% of branch coverage. CO2 refrigerant properties — including its non-toxic, non-flammable nature and ability to operate efficiently at low temperatures — make it technically suitable for food-safe refrigeration and processing applications. The sparse coverage in this corpus, combined with Shanghai Ocean University’s specific focus on food preservation subclasses, suggests an early-stage research interest that has not yet attracted commercial IP investment. Entry requires cross-domain expertise in food safety standards and refrigeration engineering.
Search this in Eureka →How leading applicants differ by technology subclass emphasis
Route coverage across the main technology branches in the current evidence set.
| Player | F25B 9 · Refrigeration & heat pumps | F25B 41 · Refrigeration & heat pumps | F25B 30 · Refrigeration & heat pumps | F25B 49 · Refrigeration & heat pumps | F25B 40 · Refrigeration & heat pumps |
|---|---|---|---|---|---|
| Xi’an Jiaotong University | Strong · 20 | Strong · 20 | Strong · 12 | Strong · 15 | Emerging · 4 |
| Tianjin University of Commerce | Strong · 11 | Strong · 8 | Moderate · 5 | Absent | Strong · 7 |
| Zhongke Carbonleng (Wuxi) High-Tech Co., Ltd. | Strong · 2 | Strong · 2 | Strong · 2 | Strong · 2 | Strong · 2 |
| Shanghai Ocean University | Strong · 3 | Strong · 2 | Absent | Strong · 3 | Absent |
| Foshan Lingyingda Energy Saving Technology Co., Ltd. | Strong · 3 | Strong · 2 | Absent | Moderate · 1 | Moderate · 1 |
| PetroChina Co., Ltd. | Strong · 2 | Absent | Absent | Strong · 2 | Absent |
| PetroChina Shenzhen New Energy Research Institute Co., Ltd. | Strong · 2 | Absent | Absent | Strong · 2 | Absent |
Frequently asked questions
The analysis covers 81 patent families in scope, with patent record counts used for applicant ranking and branch distribution — a single family can generate multiple records across jurisdictions and IPC classes.
Xi’an Jiaotong University leads with 22 patent records, more than double the second-ranked applicant, Tianjin University of Commerce, which holds 12 patent records.
The lifecycle evidence classifies the field as Decline, with annual filings easing back from a peak of 15 records in 2019. The most recent filing years (2024–2025) show provisional figures that may be understated due to publication lag, so a definitive assessment of current-year volume is not yet possible from this data.
China overwhelmingly dominates with 93 patent records. The United States follows with 7 records, and WIPO (PCT), Canada, Europe (EPO), and Japan each account for 3 or fewer records, indicating that IP protection outside China is very limited within this corpus.
Co-applicant activity is minimal. Two collaboration pairs are identified: Midea Group and GD Midea Heating and Ventilating Equipment (2 joint filings), and Xi’an Jiaotong University with the State Grid Shaanxi Electric Power Research Institute (1 joint filing). Most applicants file independently.
F24H (Fluid heaters and water heaters) with 16 records and the food-related branches A23B and A23L with 4 and 5 records respectively are the most notable adjacent branches with relatively sparse coverage. F28D (Heat-exchange apparatus) at 7 records and B60H (Vehicle heating and air conditioning) at 2 records also represent areas with limited IP density relative to the core F25B domain.
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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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