PlainPatent

CPC technology class · F28

F28F - Details OF Heat-exchange AND Heat-transfer Apparatus

Details of heat-exchange and heat-transfer apparatus, of general application. 10,136 US utility patents granted 2015–2025, with the leading assignees and year-by-year filing trajectory.

10,136
US patents granted
F28
Parent CPC class
20
Active assignees
+21%
5-yr velocity

The verdict

Details OF Heat-exchange AND Heat-transfer Apparatus ranks #169 of 670 CPC technology areas - 10,136 US patents granted since 2015, with filing up 21% over five years.

#169
of 670 CPC technology areas
10,136
US patents granted, 2015–2025
Hamilton Sundstrand (…
leading assignee (273)
+21%
filing velocity, last 5 yrs
Top assignee: Hamilton Sundstrand Corporation (hsc) (273 patents)

CPC subclass F28F - DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION - covers 10,136 US utility patents granted between 2015 and 2025 according to USPTO PatentsView records, within the broader CPC class F28 (HEAT EXCHANGE IN GENERAL). See our CPC classification guide for how the system works.

The competitive landscape in F28F is shaped by 20 distinct companies actively filing in this space. Hamilton Sundstrand Corporation (hsc) leads with 273 patents, followed by Mahle International Gmbh at 207 grants and Hanon Systems at 129.

Filing activity in F28F is up 21% over the past five years versus 2015-2019, a sharp acceleration suggesting an emerging or fast-moving technology area. All counts come directly from USPTO PatentsView and reflect US granted utility patents only.

Is F28F innovation accelerating?

US utility-patent grants per year in F28F, 2015–2025 - recent five years are up 21% versus 2015–2019.

4006008001,0001,2001,400 20152016201720182019202020212022202320242025 616

Who leads F28F?

The 12 most active assignees in DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION - wider bars mean more grants

patents

What this shows Hamilton Sundstrand (… is the most active filer in F28F, holding 273 of the 10,136 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
View data table
Top patent holders in CPC subclass F28F
Rank Company Patents in F28F
#1 Hamilton Sundstrand Corporation (hsc) 273
#2 Mahle International Gmbh 207
#3 Hanon Systems 129
#4 Daikin Industries, Ltd. 124
#5 Valeo Systemes Thermiques 115
#6 Carrier Corporation 114
#7 ALFA Laval Corporate AB 107
#8 ASIA Vital Components Co., Ltd. 106
#9 DANA Canada Corporation 106
#10 Modine Manufacturing Company 88
#11 Cooler Master Co., Ltd. 67
#12 Denso International America, Inc. 66
#13 Trane International Inc. 66
#14 UACJ Corporation 48
#15 Rheem Manufacturing Company 44
#16 Sanhua (hangzhou) Micro Channel HEAT Exchanger Co., Ltd. 43
#17 Kyungdong Navien Co., Ltd. 42
#18 Furukawa Electric Co., Ltd. 38
#19 Linde Gmbh 37
#20 Baltimore Aircoil Company, Inc. 37

About This Class

CPC subclass F28F belongs to class F28.

10,136 patents were granted in this class between 2015 and 2025.

20 companies actively patent in this space.

Classification System

Cooperative Patent Classification (CPC) is a hierarchical patent classification system used by the USPTO and EPO.

← All Technology Classes Technology Rankings →

Footprint here vs. claim strategy

Each dot is a leading F28F assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 F28F assignees by class footprint. Bubble size = patents in F28F. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Top 14 F28F assignees by class footprint. Bubble size = patents in F28F. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 681012141618 050100150200250300 Patents in F28F Avg claims / patent (company-wide) Hamilton Sundstrand (…Mahle InternationalHanon SystemsDaikin IndustriesValeo Systemes Thermi…CarrierAlfa Laval Corporate…Asia Vital ComponentsDana CanadaModine ManufacturingCooler MasterDenso International A…Trane InternationalUacj
Top 14 F28F assignees by class footprint. Bubble size = patents in F28F. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Frequently Asked Questions

What is CPC class F28F?
CPC subclass F28F covers DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION. It belongs to CPC class F28 (HEAT EXCHANGE IN GENERAL), with 10,136 US utility patents granted since 2015.
How many patents have been filed in F28F?
10,136 US utility patents were granted in CPC subclass F28F between 2015 and 2025, based on USPTO PatentsView data.
Which company holds the most patents in F28F?
Hamilton Sundstrand Corporation (hsc) leads F28F with 273 patents, making it the most active assignee in this technology area.
How is patent data for F28F collected?
Patent data comes from USPTO PatentsView, a public research dataset maintained by the United States Patent and Trademark Office. It covers all US granted utility patents and assigns CPC codes based on the technology described in each patent.
What is the difference between CPC class and subclass?
A CPC class (e.g., F28) is a broad technology category. Subclasses like F28F provide finer granularity within that category. PlainPatent organizes data at the subclass level (4-character codes) for the most useful view of technology domains.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from USPTO PatentsView - official U.S. government patent data. See our methodology for computation details. Retrieved and formatted by PlainPatent Editorial

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.