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Run your analysis now →https://www.patsnap.com/resources/blog/rd-blog/ventilation-and-energy-recovery-systems-patent-landscape/ · Patsnap · data cut-off 2026-07-31 · downloaded from the live page
Patent Landscape · HVAC SystemsVentilation and Energy Recovery Systems Patents: Who Files, What's Claimed, and Where the Filing Cooled Off
- Filing peaked in 2018 at 8 families then fell to zero at the 2022 midpoint, a pattern that reads as claim consolidation rather than sustained growth.
- 27 families sit almost entirely inside F24F with only thin spillover into F28D heat-exchange apparatus and single-digit presence in sterilising and building-structure classes.
- United States, Canada and China dominate receiving offices 12, 8 and 7 filings respectively, leaving most other jurisdictions unfiled for this claim scope.
27
Published Records
70%
Top-5 Share of All Records
-100%
3-Yr Growth (lag-adjusted)
US
Leading Jurisdiction
Published byPatsnap Research··7 min readSourced from Patsnap Eureka
Overview
What this landscape covers
This dataset tracks patent families combining energy recovery ventilation, heat recovery ventilators and fresh air systems with technical claim language around sensible efficiency, enthalpy wheels, cross-contamination control, filter pressure drop and demand-controlled ventilation, filtered to F24F12, F24F7 and F28D9. The scope is narrow by design: it captures the mechanisms that make a recovery ventilator work, not general HVAC ductwork or thermostats.
Across 27 published families the filing curve is not a growth story. It rose to a peak in 2018 and had gone flat by the 2022 midpoint, which for a mechanical HVAC subfield usually signals that the obvious architectures — wheel-based enthalpy exchange, cross-flow plate cores, defrost bypass logic — were staked out early and later filers are working narrower refinements around them.
Family filings by year, 2017-2026
Source: Patsnap Eureka. Assignee ranking and totals. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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The data
Filing trend and technology composition
27 patent families published between 2015 and the 2026 cut-off, concentrated overwhelmingly in air-conditioning and ventilation apparatus claims.
A peak, then a flat line
Filings ran 4 in 2017 and climbed to a peak of 8 in 2018. By the 2022 midpoint annual filings had dropped to zero, and the curve has not recovered since — a pattern consistent with an early land-grab on core mechanisms followed by a pause in new entrants, rather than a technology still being built out. Because publication lags filing by roughly 18 months, the final year or two of any such trend will always look thinner than it eventually turns out to be.
Concentrated in F24F, thin everywhere else
F24F (air conditioning and ventilation) accounts for all 27 records, with F28D (heat-exchange apparatus) appearing in 5 and F28F (heat-exchanger details) in only 2. Sterilising/disinfecting (A61L) and building-structure classes (E04H, E04B) each register in the low single digits — evidence that filers are claiming the ventilation mechanism itself far more than adjacent building-integration or sterilisation angles.
Shares are the percentage of the 27 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Source: Patsnap Eureka. Filing trend and technology composition. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.
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The prior art carrying the most citation weight
Representative record
Energy recovery ventilation smoke evacuation (US20170299214A1)
TYCO FIRE & SECURITY GMBH
A control system with one or more smoke sensors measuring smoke level within a building and outputting a signal; a controller runs the energy recovery ventilation system in a normal energy-recovery mode when smoke is below a threshold and switches it to a smoke-evacuation mode when the threshold is exceeded.Filed by Tyco Fire & Security GmbH, published 2017-10-19.
Most-cited records in this landscape
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5490557A | Housing for a heat recovery ventilator with fans hingedly mounted to housing | 39 |
| 2 | US20190063780A1 | Integrated Heat And Energy Recovery Ventilator System | 26 |
| 3 | US20130252537A1 | Energy recovery ventilation smoke evacuation | 23 |
| 4 | CN103512156A | 一种空调新风系统的节能方法及新风负荷梯级处理装置 | 19 |
| 5 | CA2509571A1 | Pressure sensitive bypass defrost system | 7 |
| 6 | CN214303073U | 一种集装箱式移动核酸检测生物实验室 | 6 |
| 7 | CN109520101A | 热回收新风系统及工作方法 | 6 |
| 8 | US20180120035A1 | High efficiency ventilation system | 3 |
| 9 | US9891005B2 | High efficiency ventilation system | 3 |
| 10 | US10598398B2 | Energy recovery ventilation smoke evacuation | 3 |
Citation counts inside this corpus favour older filings that later applicants had to cite around; treat them as markers of influence on subsequent drafting, not as a signal of which patents are commercially strongest today.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
Source: Patsnap Eureka. Citation counts and representative records. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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What the numbers mean for a filing decision
Three patterns stand out once the raw counts are read against filing dates and claim classes.
Filing momentum
8 in 2018 → 0 by 2022
peak to flat
The core mechanism was claimed early
The peak year of 8 families in 2018, followed by a drop to zero filings at the 2022 midpoint, suggests the foundational architectures for enthalpy exchange and cross-contamination control were largely staked out within a few years rather than built up gradually.
Filing trend, 2017-2026
Class concentration
27 of 27 in F24F
single-subclass dominance
Almost no claims sit outside ventilation apparatus itself
Every family in this set touches F24F, while F28D heat-exchange apparatus appears in only 5 and F28F heat-exchanger details in just 2. Filers are protecting the ventilator mechanism, not the surrounding heat-exchange hardware or building integration.
IPC composition
Jurisdiction spread
US 12 · Canada 8 · China 7
receiving offices
Three offices carry nearly the whole dataset
United States, Canada and China together account for the bulk of receiving-office activity, with the US narrowly ahead. A filer targeting other major ventilation markets outside these three would be filing into comparatively unclaimed territory for this specific claim scope.
Receiving office counts
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Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to ventilation and energy recovery systems, with the prior art for and against each one.
Co-filing is rare and small
| Assignee | Co-assignee | Shared families |
|---|---|---|
| RICH DAVID | KRIMMEL KEVIN | 3 |
| WILEY JOSIAH | LONGMAN MICHAEL G | 2 |
| PUTTAGUNTA SRIKANTH | CLEARY BARNETT | 2 |
| PUTTAGUNTA SRIKANTH | ALDRICH ROBB | 2 |
Only 4 co-assignee pairs appear across the dataset, the strongest being a single pairing filing together 3 times — this is a field of largely independent filers, not joint-development consortia.
Source: Patsnap Eureka. Co-assignee relationships and derived observations. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
Players
Who is active, and where the gaps sit
Recent-year momentum across the tracked assignees, including established HVAC names and academic filers, shows zero new filings in the latest year for every one of them — consistent with the broader flat trend rather than any single company's retreat.
Momentum check
0 in latest year
across tracked assignees
No assignee is currently active
Every assignee surfaced in the recent-year momentum data, from established filers like Ruskin Co to academic entrants such as Tsinghua University, shows zero filings in the most recent year. This tracks with the dataset's flat post-2022 trend rather than indicating any one firm has exited.
Recent-year momentum
Co-filing pattern
3 shared filings
strongest pair
A small circle of repeat co-inventors
The strongest co-assignee relationship in the dataset is a pairing that filed together 3 times; two further pairs each filed together twice. Co-filing overall is limited to 4 pairs across the full set of 27 families.
Co-assignee pairs
Institutional filers
2 academic/institutional names
in momentum list
Chinese universities and design institutes are present but quiet
Tsinghua University and the Guangzhou Design Institute Group appear among the tracked assignees but, like every other name in the momentum data, register no filings in the latest year — institutional interest exists but has not translated into recent output.
Assignee momentum
Recent-year filing momentum by assignee
| Assignee | Recent year | YoY |
|---|---|---|
| RUSKIN CO | 0 | — |
| RICH DAVID | 0 | — |
| KRIMMEL KEVIN | 0 | — |
| Tsinghua University | 0 | — |
| Guangzhou Design Institute Group Co., Ltd. | 0 | — |
| WILEY JOSIAH | 0 | — |
| STEVEN WINTER ASSOCS | 0 | — |
| RUSKIN ROOFTOP SYST | 0 | — |
Source: Patsnap Eureka. Assignee-level momentum. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
What's next
Where to take this
The flat filing trend and narrow IPC concentration point to specific next steps for anyone evaluating freedom to operate or new filing strategy in this space.
Check the cited prior art before drafting
The most-cited records in this set, including the smoke-evacuation and integrated heat-and-energy-recovery filings, define the claim boundaries later filers had to work around. Reviewing them first narrows where a new claim can sit.
Explore cited prior art in EurekaTest the under-claimed branches
Sterilisation-integrated units and defrost-bypass control show only single-digit representation across the dataset. A claim drafted specifically into one of these branches has less prior art to design around than a general enthalpy-exchange claim.
Run a white space search in EurekaWatch for renewed filing activity
Every tracked assignee shows zero filings in the latest year. Because publication lags filing by about 18 months, it is too early to call this a permanent exit — monitoring the next reporting cycle will confirm whether filing has genuinely stopped or is simply not yet visible.
Set up assignee monitoring in EurekaSource: Patsnap Eureka. Forward-looking reading of the same dataset. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
FAQ
Common questions on this landscape
Citation counts inside this dataset point to a small set of older US filings as the most influential, led by a 1990s housing design for a heat recovery ventilator with hinged fan mounting, cited 39 times within this corpus. More recent filings covering integrated heat-and-energy recovery and smoke-evacuation control also carry heavy citation counts. These figures reflect influence on later drafting inside the searched corpus, not current commercial dominance, since older patents naturally accumulate more citations over time.
Filing activity peaked at 8 families in 2018 and had fallen to zero by the 2022 midpoint, with no clear recovery through the most recent tracked years. That is a flat-to-declining pattern rather than growth. Because publication typically lags actual filing by about 18 months, the most recent one or two years in any such trend will look thinner than they eventually prove to be, so some caution is warranted before calling the field fully dormant.
The United States leads with 12 filings by receiving office, followed by Canada with 8 and China with 7. These three jurisdictions account for nearly all the receiving-office activity captured in this 27-family dataset. A company planning to file into other major ventilation markets outside this trio would be entering comparatively unclaimed territory for this specific claim scope, though that also means less established prior art to search against.
The dataset is heavily concentrated in F24F ventilation apparatus claims, with only thin coverage in adjacent classes: heat-exchanger details, sterilising integration and building-structure claims each register in the low single digits. Sub-areas such as enthalpy wheel cross-contamination sealing, filter pressure-drop sensing integration, and sterilisation-integrated fresh air units show comparatively little claimed prior art relative to the core mechanism claims, making them worth checking first before assuming a broad claim is already blocked.
Rarely. Only 4 co-assignee pairs appear across the full 27-family dataset, and the strongest of those filed together just 3 times. Most patents in this landscape are filed by a single assignee working independently rather than through joint-development arrangements, which is typical for a mechanical HVAC subfield where component suppliers and individual inventors often file solo rather than in consortium.
Answers are grounded in the same dataset. Derived from a Patsnap search on Ventilation and Energy Recovery Systems covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish.Run this in Eureka MCP
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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.