Air Purification Patents: Leaders, Trends & White Space 2026
- Filing peaked in 2017 at 32 records and has drifted down since, with the 2022 midpoint at 17 — a flat-to-declining trend rather than a growth story, even allowing for publication lag in the most recent years.
- F24F (air conditioning/ventilation) and B01D (separation/filtration) dominate the IPC mix, appearing in 171 and 141 of 223 records respectively, while A61L sterilising claims sit far behind at 65 — sensor-integration and disinfection framing is a secondary layer on a filtration core.
- Co-assignment is rare — only 10 pairs across the dataset, and momentum in the latest year is thin across the board, with most tracked assignees showing zero recent filings and only one showing any activity at all.
Filing growth compares 2021 (10 records) with 2024 (4) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 223 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Indoor air purification patenting spans three overlapping layers: mechanical filtration (HEPA media, filter geometry, clean air delivery rate claims), active treatment (ozone byproduct control, UV and ionisation under A61L), and system intelligence (sensors, airflow control, filter-life estimation). The search string used here anchors on clean air delivery rate, HEPA media, ozone byproduct, VOC removal and noise at operation — the technical vocabulary that separates a marketing claim from an enforceable one.
Two hundred and twenty-three published families sit inside the 2015–2026 window, concentrated in filings routed through the United States, the EPO and the PCT system, with a smaller but present cluster of national filings in India, China and Canada. That receiving-office spread suggests the technology is treated as globally relevant but not yet aggressively defended in every jurisdiction at once.
Filing trend and technology composition
Two views of the same 223-family dataset: how filing volume has moved year over year, and which IPC subclasses carry the claim weight.
A peak in 2017, then a flat-to-declining run
Filing volume peaked at 32 records in 2017 and had fallen to 3 by 2026, with the 2022 midpoint at 17. Because publication typically lags filing by around 18 months, the last one to two years understate true filing activity — but the multi-year direction from 2017 through 2022 is decline, not growth.
Filtration and ventilation carry the claim weight
F24F (air conditioning and ventilation) appears in 171 records and B01D (separation processes) in 141, together forming the technical core of the field. A61L (sterilising/disinfecting) trails at 65, and B01J, A47L, B01L, B60H and G01N each appear in single digits to low double digits — present as adjacent framing rather than as a competing technical centre.
Shares are the percentage of the 223 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Air Purification for Indoor Environments with Eureka
This page is one run against one query. Ask Eureka your own question about air purification for indoor environments and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
An air purifier and a method for controlling an air purifier
An air purifier uses a filter unit and a sensor for sensing the matter to be filtered. By monitoring the performance of the air purifier combined with information about the filter unit, it is possible to determine a volume of the space in which the air purifier is deployed.Filed by Versuni Holding B.V. (2018-10-11). The claim links sensor readings and filter-unit data to an inferred room volume — a data-driven layer on top of a physical filtration mechanism.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20180154297A1 | Air purifier with intelligent sensors and airflow | 313 |
| 2 | US6494940B1 | Air purifier | 293 |
| 3 | US4629482A | HEPA room air purifier | 162 |
| 4 | US7837958B2 | Device and methods of providing air purification in combination with superficial floor cleaning | 127 |
| 5 | US20150306533A1 | Air Purifier with Intelligent Sensors and Intellectual Airflow | 115 |
| 6 | US20080206092A1 | Device And Methods Of Providing Air Purification In Combination With Superficial Floor Cleaning | 84 |
| 7 | WO2012066453A1 | Control of air treatment device with filter | 77 |
| 8 | US6716406B2 | Control system for a photocatalytic air purifier | 76 |
| 9 | US20030021720A1 | Control system for a photocatalytic air purifier | 69 |
| 10 | US20120137876A1 | Room air purifier | 54 |
Citation counts inside a searched corpus favour older filings that have had more time to accumulate references; treat them as a signal of influence on later claim drafting, not as a ranking of current commercial importance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns worth acting on: where claim density already sits, what the citation record signals, and how thin recent activity actually is.
The field is not accelerating
Volume has moved from a 2017 peak of 32 down through a 2022 midpoint of 17 to just 3 in the most recent year. Even discounting the last year or two for publication lag, the multi-year direction is downward, not a growth curve a new entrant can ride.
Filtration and ventilation, not disinfection, is the core
F24F and B01D together anchor the great majority of records. A61L sterilising claims are present but secondary, meaning fights over ozone byproduct control and UV treatment sit on a smaller, less crowded slice of the map than fights over filter media and airflow.
Sensor-integrated airflow claims set the reference point
The most-cited record in the corpus combines intelligent sensors with airflow control, and an earlier filing with near-identical framing also ranks highly — evidence that examiners and drafters keep returning to sensor-plus-airflow as the baseline to distinguish from.
Filing here is mostly solo
Only 10 co-assignee pairs surface across 223 families, and the strongest of them link a single corporate assignee to named individual inventors rather than to another company. Joint corporate filings are the exception, not the pattern.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to air purification for indoor environments, with the prior art for and against each one.
Who is filing, and how much momentum is left
Recent-year momentum is thin across the tracked assignee set, which — combined with the declining filing trend — points to a field where claim positions are largely already staked rather than being actively contested.
One assignee still active
Of the assignees tracked for recent-year momentum, only one shows any filings in the latest year at all, at a modest two records. Every other tracked assignee shows zero in the same window.
Corporate-individual pairs, not alliances
The strongest co-assignee links pair a single corporation with named inventors rather than with another firm, suggesting internal R&D credit rather than cross-company collaboration is the norm in this dataset.
US-anchored, with real PCT and EPO weight
The United States is the single largest receiving office, but EPO and WIPO/PCT routes carry substantial volume too, with India, China and Canada forming a smaller secondary tier — a field defended broadly rather than in one jurisdiction alone.
| Assignee | Recent year | YoY |
|---|---|---|
| Microjet Technology Co., Ltd. | 2 | — |
| Koninklijke Philips N.V. (Royal Philips) | 0 | — |
| Blueair AB | 0 | — |
| Lifeaire Systems, LLC | 0 | — |
| Ferro Corporation | 0 | — |
| S.C. Johnson & Son, Inc. | 0 | — |
| Youers Biotechnology Co., Ltd. | 0 | — |
| Carrier Corporation (USA) | 0 | — |
Where to take this analysis
A landscape like this tells you where claim space is occupied and where filing has slowed — the next step is testing a specific claim idea or a specific competitor's position against the full document set.
Stress-test a claim idea
Take a candidate claim in an under-claimed branch — such as an ozone byproduct suppression circuit — and check it against the full set of 223 families rather than the top-cited handful.
Explore in Patsnap EurekaTrack a specific assignee
Recent-year momentum is concentrated in a single tracked assignee; a deeper pull on that entity's full portfolio and filing cadence would confirm whether it is expanding or consolidating.
Explore in Patsnap EurekaMap the sensor-airflow lineage
The most-cited records share near-identical sensor-plus-airflow framing across different filing years; tracing that lineage clarifies which continuations still constrain new drafting.
Explore in Patsnap EurekaCommon questions on air purification patents
Based on this dataset, filing volume is declining rather than growing: it peaked at 32 records in 2017, fell to a midpoint of 17 by 2022, and stood at just 3 in the most recent tracked year. Publication typically lags filing by around 18 months, so the very latest year or two will always look thinner than it eventually turns out to be. Even accounting for that lag, the multi-year trend from 2017 through 2022 is a clear decline, not a plateau or a ramp-up.
Ventilation and airflow control (IPC class F24F) and filtration/separation (B01D) dominate, appearing in 171 and 141 of 223 records respectively. Sterilising and disinfecting technology (A61L), which covers UV and ozone-based treatment, appears in only 65 records — present but clearly secondary to the mechanical filtration and airflow core. Smaller adjacent classes like catalysis (B01J), cleaning appliances (A47L) and vehicle HVAC (B60H) appear in single-digit to low-double-digit counts, marking them as fringe rather than central to the field.
The most-cited record in this corpus is a filing on an air purifier with intelligent sensors and airflow control, cited 313 times, followed by an earlier general-purpose air purifier patent and a HEPA-specific room air purifier filing. High citation counts inside a searched corpus tend to favour older records simply because they have had more years to accumulate references, so treat this as a map of which claim language later drafters had to work around — not as a ranking of which patents matter most today.
The IPC composition and citation data point to a handful of comparatively thin branches: ozone byproduct suppression, noise-at-operation acoustic claims, VOC-specific sorbent media, and sensor-fusion approaches to filter-life estimation. These sit adjacent to the dense F24F/B01D core rather than replacing it, meaning a workable strategy is often to combine a well-established filtration mechanism with a claim element from one of these thinner branches rather than trying to claim airflow or HEPA media outright.
Mostly alone. This dataset finds only 10 co-assignee pairs across 223 families, and even the strongest of those pairs link a single corporate assignee to named individual inventors rather than to a second company. That pattern suggests joint ventures and cross-licensing arrangements are uncommon in this field, and that most competitive intelligence work should focus on single-assignee portfolios rather than looking for alliance structures.
The United States leads as a receiving office with 67 filings, followed by the European Patent Office at 47 and the WIPO/PCT route at 34, with India, China and Canada forming a smaller secondary tier at 15, 13 and 9 respectively. This spread indicates the technology is filed with an eye toward broad international protection through PCT and EPO routes rather than being defended in a single home jurisdiction alone.
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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.