F28 HEAT EXCHANGE IN GENERAL
Classification Context
- Section:
- MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- Class:
- HEAT EXCHANGE IN GENERAL
Description
Covers apparatus and methods for transferring thermal energy between fluids or between a fluid and a solid surface, including heat exchangers, condensers, evaporators, and cooling devices. Encompasses various heat transfer mechanisms such as direct contact, indirect contact through walls, and phase-change processes, with designs ranging from simple tube-and-shell configurations to complex multi-stage systems. Includes control systems, accessories, and manufacturing techniques specific to heat exchange equipment, but excludes specialized applications assigned to other classes (such as refrigeration systems in F25 or internal combustion engine cooling in F01).
Filing statistics
IPC F28 recorded 326,475 patent applications worldwide between 2013 and 2023, summed across its 5 subclasses. Annual filings grew from 17,828 in 2013 to 40,344 in 2023 (+126%), peaking at 42,329 applications in 2020. The most active applicants in class F28 are VALEO SYSTEMES THERMIQUES (1,902 applications), MITSUBISHI ELECTRIC CORPORATION (1,327 applications) and GREE ELECTRIC APPLIANCES (1,152 applications).
Source: EPO PATSTAT, worldwide filings
In class comparison
F28 comprises 5 subclasses with filings; the largest is F28D with 42.1% of the class's 326,475 applications between 2013 and 2023.
| Rank | Subclass | Title | Applications | Share |
|---|---|---|---|---|
| 1 | F28D, Heat-Exchange Apparatus, Not Provided for in Another Subclass, in Which the Heat-Exchange Media Do Not Come Into Direct Contact; Heat Storage Plants or Apparatus in General | Heat-Exchange Apparatus, Not Provided for in Another Subclass, in Which the Heat-Exchange Media Do Not Come Into Direct Contact; Heat Storage Plants or Apparatus in General | 137,561 | 42.1% |
| 2 | F28F, Details of Heat-Exchange or Heat-Transfer Apparatus, of General Application | Details of Heat-Exchange or Heat-Transfer Apparatus, of General Application | 136,716 | 41.9% |
| 3 | F28C, Heat-Exchange Apparatus, Not Provided for in Another Subclass, in Which the Heat-Exchange Media Come Into Direct Contact Without Chemical Interaction | Heat-Exchange Apparatus, Not Provided for in Another Subclass, in Which the Heat-Exchange Media Come Into Direct Contact Without Chemical Interaction | 18,596 | 5.7% |
| 4 | F28G, Cleaning of Internal or External Surfaces of Heat-Exchange or Heat-Transfer Conduits, e.g. Water Tubes of Boilers | Cleaning of Internal or External Surfaces of Heat-Exchange or Heat-Transfer Conduits, e.g. Water Tubes of Boilers | 17,528 | 5.4% |
| 5 | F28B, Steam or Vapour Condensers | Steam or Vapour Condensers | 16,074 | 4.9% |
Source: EPO PATSTAT, worldwide filings
Related Keywords
5 direct subcodes
Child Classifications
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- F28B STEAM OR VAPOUR CONDENSERS
- F28C HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA COME INTO DIRECT CONTACT WITHOUT CHEMICAL INTERACTION
- F28D HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT; HEAT STORAGE PLANTS OR APPARATUS IN GENERAL
- F28F DETAILS OF HEAT-EXCHANGE OR HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28G CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OF BOILERS
Top Applicants
Top 10 applicants by patent filings, 2013–2023, worldwide · Source: EPO PATSTAT
- VALEO SYSTEMES THERMIQUES FR 1,902
- MITSUBISHI ELECTRIC CORPORATION JP 1,327
- GREE ELECTRIC APPLIANCES 1,152
- MAHLE INTERNATIONAL DE 999
- ALFA LAVAL SE 960
- HANON SYSTEMS KR 917
- DENSO CORPORATION 905
- DENSO CORPORATION JP 802
- CHINESE ACADEMY OF SCIENCES 787
- XIAN THERMAL POWER RESEARCH INSTITUTE COMPANY 762