Heat Pump Drying Patents: Top Companies & Filing Trends 2026
- 57.1% of all 56 records sit with just five assignees, and 92.9% sit with ten — a small group has occupied most of the claim space in this field.
- Filings peaked in 2024 at 6 in a year with only two full years of prior data, so the trend line is short and any growth-rate claim would be premature.
- D06F and F26B each cover roughly half the records (50.0% and 44.6%), while F25B heat-pump/refrigeration claims sit under a third — a gap between drying-appliance claims and the thermodynamic core.
Top-5 share is the combined record count of the five largest assignees divided by all 56 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This review covers 56 published records filed or published between 2015 and mid-2026 that combine heat pump or closed-loop drying architecture with a specific technical claim — moisture extraction rate, coefficient of performance, condensate handling, refrigerant selection, defrost strategy or drying kinetics. That combination narrows the field to records where the drying cycle and the thermodynamic cycle are claimed together, rather than either one alone.
Filing activity is concentrated among a small set of assignees, with appliance-scale claims (D06F, F26B) outnumbering refrigeration-cycle claims (F25B) inside the same record set. Publication lags filing by roughly 18 months, so the 2025-2026 count in the trend chart understates real filing activity for those years.
Filing trend and technology composition
Two views of the same 56 records: how filings moved year over year, and which IPC subclasses carry the claims.
Filing trend, 2017-2026
Filings ran at low single digits through most of the period, reaching a peak of 6 in 2024. With fewer than four complete years once publication lag is accounted for, no growth rate can be stated reliably from this trend alone.
IPC subclass composition
D06F (laundering, drying & ironing) and F26B (drying) each appear in roughly half of the 56 records, confirming this is primarily an appliance and drying-process field. F25B (refrigeration & heat pumps) appears in 26.8% of records, and B01D, F24F, F24H, H01M and A47L each cover a smaller slice — these are the adjacent branches, not the core, of most filings.
Shares are the percentage of the 56 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Heat Pump Drying and Energy Recovery with Eureka
This page is one run against one query. Ask Eureka your own question about heat pump drying and energy recovery and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited prior art
SG83109A1 — Two stage heat pump dryer
Filed by the National University of Singapore and published in 2001, this record claims a two-stage heat pump drying arrangement — an early example of the staged-cycle approach that recurs across the later, more heavily cited US filings in this dataset.Representative record; number, assignee and date rendered from the underlying data.
View full record| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20050066538A1 | Heat pump clothes dryer | 282 |
| 2 | US7055262B2 | Heat pump clothes dryer | 207 |
| 3 | US20060179676A1 | Heat pump clothes dryer | 148 |
| 4 | US7665225B2 | Heat pump clothes dryer | 91 |
| 5 | US7020985B2 | Multiple outlet air path for a clothes dryer | 79 |
| 6 | US6164073A | Method and apparatus for adapting steady flow with cyclic thermodynamics | 51 |
| 7 | WO2005032322A2 | Heat pump clothes dryer | 41 |
| 8 | WO2000036344A1 | A modular heat pump system for drying and air-conditioning | 29 |
| 9 | JP1990146475A | dryer | 17 |
| 10 | US20050210698A1 | Multiple outlet air path for a clothes dryer | 15 |
Citation counts favour older records simply because they have had longer to accumulate citations inside the corpus — read them as a signal of influence on later filings, not as a signal of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three findings a reader could not get from browsing the raw record list.
A small group holds most of the claim space
Five assignees account for 57.1% of all 56 records, and ten account for 92.9%. That leaves a long tail of single- or double-filing entrants working around a fairly small set of occupied positions.
Appliance claims outnumber refrigeration-cycle claims
D06F (drying appliances) appears in half of all records while F25B (refrigeration & heat pump cycles) appears in barely more than a quarter. Filers are more often claiming the dryer mechanism than the thermodynamic cycle inside it.
Early US heat pump dryer filings anchor the citation graph
The five most-cited records in this dataset are all early heat pump clothes dryer filings, one carrying 282 citations. Their influence on later drafting is clear, but citation age means they say more about historical framing than present-day white space.
US filings lead receiving offices, EPO and Japan follow
United States filings (17) outnumber EPO (8), Japan (5), WIPO/PCT (5), Australia (3) and Canada (3) among the receiving offices captured here, suggesting the US is the primary contested jurisdiction for this technology.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to heat pump drying and energy recovery, with the prior art for and against each one.
Who is filing, and where the gate sits
The leader in this dataset holds 11 records; fifth place holds 5, tenth place holds 4 — the ranking drops off quickly after the top few names, into a long tail of one- and two-record filers.
One assignee sits well ahead of the field
The leading assignee in this 26-company ranking holds 11 of the 56 records in scope, more than double the fifth-place count of 5. That gap suggests a sustained filing programme rather than opportunistic single filings.
The mid-field is tightly bunched
Between fifth place (5 records) and tenth place (4 records) the gap is a single filing, meaning several assignees are clustered at a similar filing intensity just below the leader.
A small cluster of individual co-inventors files together repeatedly
Three of the strongest co-assignee pairs in the dataset share the same three names, each pairing appearing together on 4 records — a tight, repeat collaboration rather than a one-off joint filing.
| Assignee | Recent year | YoY |
|---|---|---|
| SELF PROPELLED RES & DEV SPECIALISTS | 0 | — |
| Whirlpool Corp | 0 | — |
| Channing Street Copper Co | 0 | — |
| National University of Singapore | 0 | — |
| Samsung Electronics Co., Ltd. | 0 | — |
| Multivector | 0 | — |
| TRUMAN JAMES C | 0 | — |
| KNIFFIN ALEXANDER B | 0 | — |
Where to take this from here
The dataset points to a few concrete next steps for a team deciding where to file or where to design around existing claims.
Check the F25B gap before drafting
With F25B present in only 26.8% of records against D06F's 50.0%, claims that tie a specific refrigeration-cycle parameter to drying performance may face less crowded prior art than appliance-mechanism claims.
Explore F25B claim spaceMap the top-10 assignees' active families
Since ten assignees hold 92.9% of all 56 records, freedom-to-operate work should start with those families rather than the long tail, which contributes little coverage individually.
Review leading assigneesTreat 2025-2026 counts as provisional
Publication lag means recent-year filing counts, including the 2024 peak of 6, will revise upward as later publications land — re-check the trend before drawing conclusions about slowing activity.
Track filing trend updatesCommon questions about heat pump drying patents
One assignee leads this 26-company ranking with 11 of the 56 records in scope, well ahead of fifth place at 5 records. The top five assignees combined hold 57.1% of all records, and the top ten hold 92.9%, which means most of the remaining companies in the ranking hold only one or two records each. Anyone doing freedom-to-operate work should prioritise the leading names before spending time on the long tail.
Within this dataset, D06F (laundering, drying and ironing) and F26B (drying) are the two largest IPC subclasses, each covering roughly half of the 56 records. F25B, the refrigeration and heat-pump cycle classification, appears in only 26.8% of records, and smaller adjacent classes like B01D (separation), F24F (air conditioning) and H01M (batteries) each cover under 11%. In short, most filings claim the drying appliance or process more than the thermodynamic cycle itself.
The trend runs from 2 filings in 2017 to a peak of 6 in 2024, with 2026 partial and understated because publication typically lags filing by around 18 months. There are fewer than four complete years of data once that lag is accounted for, so no reliable growth rate can be stated from this dataset alone. Treat the recent-year dip as a data artefact rather than a real slowdown until later publications land.
The clearest gaps sit in the classes that appear alongside the drying core but at low frequency — B01D condensate/separation handling at 10.7% of records, F24F air-conditioning overlap at 8.9%, and H01M battery-integration overlap at 7.1%. These are areas where the drying-and-refrigeration combination is claimed far less often than the core D06F/F26B appliance space, suggesting room for a first claim that ties one of these adjacent mechanisms directly to drying performance or refrigerant handling.
Among the receiving offices captured in this dataset, the United States leads with 17 filings, followed by the European Patent Office with 8 and Japan with 5. WIPO/PCT filings also total 5, with Australia and Canada each at 3. This pattern points to the US as the primary contested jurisdiction for this technology, with EPO and Japan as secondary but still active filing destinations.
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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.
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.