US 11098908

I'll search for authoritative information on this patent, including any 2026 litigation activity.

Let me verify the granted claim set and check for any litigation involving this patent or its assignee.

Search scope and results

I searched for the exact string 11098908 against patent databases and general web/CourtListener/Federal Circuit material for 2026. Below is what the authoritative and secondary sources show, separated from what I could not confirm.

1. Bibliographic summary

Abstract (verbatim): "In a construction method of an air conditioning system, the respective rooms are provided with air intake sections 9a to 9d, 18a to 18d which spout air sent from blowers 40a to 40d, 41a to 41d, an exhaust section 52 which forms discharged air current directed from the respective rooms toward the return compartment is provided between the respective rooms and the return compartment, and the plurality of blowers 40a to 40d, 41a to 41d and at least one air conditioner are disposed in the return compartment. Air discharged from the plurality of rooms in the building 1 by the air conditioner 30b operated by the return compartment is adjusted in temperature and moisture in the return compartment, and wind is sent into the plurality of rooms in the building 1 by the blowers 40a to 40d, 41a to 41d, and air conditioning in the building 1 can be performed."

Same-family document surfaced during the search: US 11,906,198 B2 (titled Air-conditioning system), from continuation application US 17/879,671 filed Aug 2, 2022, sharing the 2016-10-21 priority date. It is a separate patent number and should not be confused with 11098908.

2. Plain-language overview of the independent claims

Important claim-text caveat. The authoritative Google Patents full text supplied to me reproduces the description and aspects but was truncated before the claims section, so I could not read the granted claims from that source directly. Two retrieved secondary sources give different claim sets, and I am flagging that discrepancy rather than smoothing it over:

• Justia's page for the pre-grant publication US 2019/0234628 A1 (patents.justia.com/patent/20190234628) lists 10 claims in which claim 1 is a construction method and claim 8 is the design method.
• Justia's page for the granted patent (patents.justia.com/patent/11098908) lists claim 1 as the design method, with the "≤70% of total blast air volume" limitation moved up into claim 1 and an added attic-space circulation limitation.

The most likely explanation is a narrowing amendment during prosecution (the design-method claim amended with the 70% and attic-space features), but I cannot verify the granted claim set from the primary source. Treat the numbering below as probable, not confirmed.

(a) Construction-method independent claim (claim 1 of the publication; corresponds to "first aspect" in the specification):
A method of installing/building an air-conditioning system in which (i) a return compartment adjacent to several rooms is formed in the building; (ii) each room gets an air intake section (e.g., a ceiling/floor spout grill) that discharges air supplied by blowers; (iii) an exhaust section is placed between each room and the return compartment to create return airflow from the rooms back into the return compartment; and (iv) multiple blowers plus at least one air conditioner are installed inside the return compartment itself. In plain terms: instead of building a dedicated air-conditioner closet/attic chamber, you put the AC unit and the room-supply fans in an ordinary circulation space — a staircase or corridor — and use it as the mixing/return plenum.

(b) Design-method independent claim (published claim 8; appears to be granted claim 1):
A method of sizing/selecting the equipment for such a system, comprising four ordered steps —

1. Air-conditioning ability determining step — compute the building's air-conditioning load and pick the AC unit's capacity.
2. Blast air volume determining step — set the supply air volume for each room from that room's capacity/size (spec: preferably ≥13 m³/h per 2.5 m³ of room, ideally ~20 m³/h).
3. Total blast air volume calculating step — sum all room volumes to get total blast volume Vh.
4. Air-conditioning air volume determining step — determine the AC unit's "optimal air-conditioning air volume" Vq from Vh.
   Then: select the blowers based on the per-room volumes; require the AC unit to have the capacity from step 1; and require the AC unit to be capable of setting an air-conditioning air volume ≤ Vq. The granted claim 1 text retrieved also recites that the optimal air-conditioning air volume is "equal to or less than 70% of the total blast air volume", and adds that air is sent from the return compartment into an attic space (airproof/heat-insulated, outside the rooms), circulated back to the return compartment, and added to the total blast air volume — i.e., deliberately inflating Vh so that the AC's lowest settable fan speed is a small fraction of it.

Dependent claims (published numbering; likely renumbered on grant):

• Claim 9: if the capacity-appropriate AC unit cannot set a volume ≤ Vq, then size the blowers so the AC's minimum settable air volume is ≤ 70% of Vh (so short-circuiting/mixing stays acceptable for small dwellings).
• Claim 10: select blowers that have air-volume adjustment means (e.g., a notch/tap switch changing fan rpm, or a shutter adjusting grill opening area) to trim per-room volumes after installation.
• Publication claims 2–7 depend from the construction claim: return compartment is a staircase (2) or a corridor (3); blower suction port avoids the AC's spout direction (4); blower suction is below the AC spout port and the AC spouts substantially horizontally (5, ±15° down); at least one exhaust section above the AC (6); total blower blast volume exceeds the AC air-conditioning air volume (7).

Worked numbers in the specification (useful for claim-construction context): Embodiment 1 — ~97.7 m² house, 4 kW cooling AC delivering 700 m³/h on weak, 8 blowers × ~150 m³/h ⇒ Vh ≈ 1,200 m³/h (58% of Vh); adding ~300 m³/h underfloor supply brings Vh ≈ 1,500 m³/h (46%). Embodiment 2 — ~79.3 m² house, 3.6 kW AC, 510 m³/h ⇒ Vh ≈ 900 m³/h (57%).

3. Litigation / CAFC 2026 docket check

I found no litigation, appeal, IPR, or ITC proceeding involving US 11,098,908 or FH Alliance Inc. Targeted searches of Federal Circuit 2026 materials and CourtListener-hosted docket documents returned no hits for either the patent number or the assignee. The only literal "11098908" match outside patent databases was an unrelated Brazilian state commercial-registry entry (11098908 DOMINUS INDUSTRIA M AQUINAS ELEVACAO CARGAS LTDA, JUCEPAR) — this is a registration number, not a patent reference, and I am not treating it as relevant.

Because I cannot query PACER, Docket Navigator, or the Federal Circuit's own docket system directly through the tools available, this is a negative search result, not proof of absence. If a 2026 appeal exists and is not yet indexed in public web sources, I would not have found it. Anyone relying on this for freedom-to-operate or litigation-monitoring purposes should confirm against PACER and the CAFC docket directly.

4. Confidence notes

• High confidence: patent number, title, inventors, assignee, application number, PCT parent, filing/issue/priority dates, CPC classes, examiner, and the abstract — all corroborated across the Google Patents text and Justia.
• Moderate confidence: the granted independent-claim wording, especially the "≤70% of total blast air volume" and "attic space" limitations appearing in claim 1. This comes from a secondary aggregator, and it conflicts with the pre-grant publication's claim ordering. Verify against the USPTO Patent Public Search or the granted patent's printed claims before relying on it.
• Explicit uncertainty: I did not independently verify (i) whether construction-method claims 1–7 survived into the granted patent, (ii) the granted claim numbering for the dependent claims, or (iii) the current claim(s) being asserted in any dispute. The specification's "first through tenth aspects" track the as-filed claim set, not necessarily the granted set.

I'll research litigation involving US patent 11098908. Let me run several searches.

Let me refine with more targeted searches.

Let me search litigation databases directly.

Findings: No litigation identified for US Patent 10,998,908

I ran targeted searches across litigation-oriented sources (Unified Patents, CourtListener/RECAP, Justia, CAFC opinions, PACER-style dockets, and general web) for the specific patent number 11098908 / 10,998,908. I found no litigation — district court, ITC, PTAB, or Federal Circuit — involving US 10,998,908.

Important search caveats

1. No positive litigation record surfaced. My searches returned only (a) unrelated patents whose numbers happen to end in "988," and (b) Brazilian judicial-recovery filings where the digits "11098908" appear as a company registration/process number, not a patent. Neither is relevant.

2. Disambiguation warning — do NOT conflate with other "’988" patents. The searches surfaced at least two different patents colloquially called the "’988 patent":

   • A semiconductor/ALD ’988 patent asserted by HiKE against ASM (complaint referencing an "XP8 system") — a different patent, different technology, different owner.
   • A PureWick/Sage district court opinion referencing ’376/’989/’407 patents — also unrelated.

   US 10,998,908 is not either of these.

What the record does show about the patent

FH Alliance Inc. is a small Japanese holder with a family of related applications (e.g., US 11,906,198; US 11,898,775; US 12,624,848), and I found no assertion campaigns, litigation funding, or infringement suits tied to any of them in the sources searched.

Limitations of this conclusion

• I could not run a dedicated PACER/Docket Navigator query, which is the most authoritative check for district court and ITC cases; CourtListener and Unified Patents coverage of very recent or sealed cases may be incomplete.
• Absence of results is not affirmative proof that no litigation exists — only that none is publicly indexed in the sources I could reach.

Bottom line: Based on available public sources as of April 26, 2026, no known litigation involves US Patent 10,998,908. A definitive negative would require a direct PACER and Docket Navigator search by patent number (and a check for any assignment/licensing activity by FH Alliance Inc.). I'd recommend confirming via a paid docket tool before relying on this for any filing or opinion.

I'll verify the structured "no proceedings" signal against live sources before writing anything.

Let me probe a few more angles — petitioner-side and patent-owner-side — before concluding.

One more pass to check litigation and defensive-aggregator angles, since those often precede or accompany PTAB filings.

Proceedings overview

Total AIA trial proceedings on file for US 11098908: 0. Breakdown by status: 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution denials — the structured USPTO Open Data Portal block supplied in this prompt reports no AIA trial proceedings, and independent web searches (PTAB, petitioner-side, patent-owner-side, and litigation angles) surfaced no IPR/PGR/CBM petition, Final Written Decision, or Federal Circuit appeal naming this patent or its owner, FH Alliance Inc.

The bottom-line defensive posture is therefore the opposite of "hardened by successful IPR defense" — the patent is simply untested. There is no PTAB record to attack or to hide behind, no claim has been canceled, and no estoppel has been created. A defendant today faces a fully intact claim set with no adverse PTAB history, but also with no prior petitioner having done the work of finding and vetting prior art.

No proceedings to report

Because the count is zero, there are no per-proceeding entries. Per the operating rules, I will not invent proceeding numbers, panels, institution dates, or dispositions. Nothing in the sources retrieved (Google Patents US11098908B2 page, PatentGuru/ipqwery assignee records, Justia, the PTAB petition documents indexed in search) references any AIA trial against this patent.

Search caveats — read these as limits, not as negatives:

• The only literal hit for the string "11098908" in my searches was an unrelated Brazilian state registry entry (DOMINUS INDUSTRIA M AQUINAS ELEVACAO CARGAS LTDA), not this patent. The string is not a reliable search key; I relied on owner name, patent title, and proceeding-number searches instead.
• USPTO ODP ingest lags newly filed petitions. A petition filed within roughly the last several weeks could exist without appearing. I found no such filing, but I cannot rule one out from search alone. Confirm directly at PTAB E2E / PTAB Center and the USPTO Patent Center for US 16/312,076.
• I also found no public district court litigation asserting this patent. That matters: IPRs overwhelmingly follow infringement suits, so the absence of both is internally consistent (see Strategic summary).

Strategic summary

Claim status: everything is UNTESTED. No claim of US11098908 has been canceled, confirmed, or construed by the Board. There is no FWD, no institution decision, and no Board claim construction to argue. Any statement about "surviving claims" would be fabricated — the correct framing is that the entire claim set is live and never challenged. Note also that I could not verify the exact claim set from the sources retrieved; the specification as published lays out ten aspects ("first aspect" through "tenth aspect") that appear to correspond to the claims, but treat the specific claim numbering and dependency structure as something to confirm against the printed claims before relying on it.

Estoppel landscape: clean slate, and that cuts both ways. Because no IPR/PGR/CBM was ever instituted on this patent, no § 315(e)(2) estoppel attaches to anyone — there is no petitioner and no privy barred from raising grounds. A defendant now is free to raise any prior-art ground, including art that a hypothetical earlier petitioner raised or reasonably could have raised. Conversely, if you file and lose on a ground, you will be statutorily barred from re-litigating that ground or any ground you reasonably could have raised — so the first petition on an untested patent should be built to be comprehensive, not incremental. Also watch the § 315(b) one-year clock from service of any complaint; absent a served complaint, there is no bar yet.

Pattern signals. No repeat petitioner, because there is no petitioner at all. No evidence of aggressive PTAB appeals by FH Alliance. No defensive aggregator (Unified Patents, RPX, etc.) is in the chain on this patent — nothing in the record suggests a third-party validity challenge has been funded. Two structural facts explain the quiet: (1) this is a method patent ("Construction method and design method of an air-conditioning system"), which is a poor IPR target relative to apparatus claims and awkward to assert against a product; and (2) FH Alliance is a Japanese foreign corporation with a small, F24F-concentrated US portfolio (roughly 8 granted US patents), not a high-volume litigant profile. Finally, the patent is part of an active continuation family sharing the 2016-10-21 priority date — US11441796B2 (app. 16/943,339), US11906198B2 (app. 17/879,671), and pending US20240142119A1 (app. 18/409,222), plus JP6857303B2, CN109477647B, and CN114576842A — so a defendant should expect sibling patents with overlapping disclosures to be available to the owner if this patent is ever invalidated. Anticipated expiration is 2036-10-21, leaving roughly a decade of exposure.

Recommended next steps

• Treat this as "no PTAB activity on file." Do not build a defense that assumes a canceled claim or a favorable FWD — none exists. The absence of IPRs is itself a signal: this patent appears never to have been publicly asserted in litigation, so no accused infringer has yet had the incentive to file.
• If you receive a demand letter or complaint, re-run the check immediately. Docket the § 315(b) one-year bar from service, and check PTAB E2E and CourtListener for any related FH Alliance filings on the sibling patents (US11441796, US11906198), because petitioners frequently challenge a whole family in parallel — the IPR2022-01203 line in my search results is an unrelated patent family and is not relevant here.
• Assess the method-claim vulnerabilities directly against the printed claims. Because the disclosed aspects are construction/design methods, the live questions for a defendant are likely (a) § 101 eligibility for a method of designing an HVAC layout, (b) divided infringement / who performs each step, and (c) the patentable weight of relative, functional language such as "less prone to be short circuited," "substantially in a horizontal direction," and the 50%/70% air-volume relationships. I have not verified that the claims recite these limitations, so confirm before relying on any of it.
• If you file an IPR, file it comprehensively. With zero estoppel on the patent and zero prior Board construction, you get one clean shot at grounds a first petitioner normally never gets back. Consider whether the 2016-10-21 priority date can be challenged through the family's Japanese priority filings, and check whether the cited background art (JP 2012-57880, discussed in the specification) and the WO2014111061A1/JP-family art indexed in searches are usable § 102/§ 103 references.
• Monitor rather than assume. My conclusion rests on the ODP block plus negative search results, not on a live PTAB docket pull. Verify status at patents.google.com/patent/US11098908/en, the USPTO Patent Center for application 16/312,076, and PTAB E2E before finalizing any opinion of counsel.

I'll research the assignment record for US 11098908 using the sources available.

Let me dig deeper into the assignee, the correspondent firm, and any litigation or later transfers.

Let me check for litigation, the company's business, and any additional recorded assignments.

Ownership Analysis — US 11,098,908 B2

"Construction method and design method of an air-conditioning system"
Assignee of record: FH Alliance Inc. · App. 16/312,076 · §371 of PCT/JP2016/081263 · Filed 2016‑10‑21 · Granted 2021‑08‑24

Source limitation (stated up front): I was unable to query assignmentcenter.uspto.gov / assignment.uspto.gov directly from this environment — only the Google Patents legal‑events record for this specific patent and secondary bibliographic databases (PatentGuru, FreePatentsOnline, OnScope/IPQwery, Espacenet) were reachable. The USPTO reel/frame for the assignment below was not exposed in any source I could retrieve, so I have deliberately left it as "not captured" rather than inventing a number. The recording date and the parties are firmly grounded. Verify the reel/frame directly at the Assignment Center search page before relying on it in a filing or diligence memo.

Inventors

Pattern note: No unusual inventor‑departure signal. Hiroishi is still Chairman of the assignee as of the 2025 press release, i.e., the lead inventor did not exit within 12 months of filing — the opposite of the "founder bails, portfolio is fire‑sold" pattern. Sugiyama does not appear on FH Alliance's later US filings (those name Kazuro Hiroishi + Mitsunori Matsubara), which is a personnel change on a going concern, not an ownership event. That change is not evidence of a fire sale and should not be cited as one.

Original assignee

FH Alliance Inc. / 株式会社FHアライアンス ("Future House Alliance") — a Japanese corporation, registered address 愛知県春日井市藤山台8丁目11番地7 (Fujiyama‑dai, Kasugai, Aichi, Japan); founded 2012.

• Line of business: Design and development of residential whole‑house air‑conditioning systems. Flagship product is the "MACH system" (マッハシステム) — a high‑air‑volume / low‑temperature‑differential whole‑house system in which one room air conditioner performs cooling, heating, ventilation, air purification and dehumidification. This is precisely the architecture claimed in the '908 patent (one air conditioner + multiple blowers in a return compartment).
• Does it ship a product embodying the claims? Yes — directly and through a licensee. FH Alliance's January 2025 press release (https://fh-a.net/) states that it granted technology to Panasonic Eco Systems North America (under Panasonic Corporation's Air Quality & Air Conditioning division) and that the MACH system was adopted in the US market whole‑house system "OASYS," launched 2025‑01‑07 and showcased at CES 2025. The same release cites an independent Fuji Keizai study (FY2023) placing FH Alliance third nationally among whole‑house air‑conditioning vendors. Granted US patents per PatentGuru/PlainPatent: ~8 US grants spanning 2021–2025, all in CPC F24F.
• Current status: Operating. No bankruptcy, dissolution, acquisition, or assignment‑to‑NPE events appear anywhere in its public record. All US filings in the family remain in FH Alliance's name.

Assignment timeline

One (1) recorded post‑filing assignment. Nothing after issuance.

• Executed: not stated in the sources retrieved (PCT filed 2016‑10‑21; the record post‑dates the filing by ~2 years) / recorded 2019‑02‑12 — Reel/frame not captured (see source limitation above; Google Patents' legal‑events table for this patent lists the 2019‑02‑12 event with no reel/frame, unlike sibling families where e.g. reel 066104/0194 is printed)
  • Conveyance: Assignment (ASSIGNMENT OF ASSIGNORS INTEREST)
  • Assignor: HIROISHI, Kazuro; SUGIYAMA, Hiromi (joint inventors)
  • Assignee: FH ALLIANCE INC.
  • Correspondent: Kratz, Quintos & Hanson, LLP (Alexandria, Virginia, US) — this is the firm of record that prosecuted the application and is listed as the agency on FH Alliance's US dockets. Flag: the recurrence is within a single client's own portfolio (FH Alliance → Kratz Quintos on this patent and its siblings), not across unrelated assignee LLCs, so it is not an NPE correspondent signal. Kratz, Quintos & Hanson is a general‑practice US prosecution firm handling foreign (notably Japanese) applicants; its appearance here is ordinary.
  • Context: Routine inventor‑to‑company assignment of the type recorded at US national‑stage entry of a PCT application — not an acquisition, not a fire sale, not a transfer to an asserter. The ~4‑month gap between the 2018 national‑stage filing of 16/312,076 and the 2019‑02‑12 recording is consistent with ordinary §371 entry housekeeping.

After issuance: no assignments, security agreements, mergers, name changes, licenses, releases, or corrections are recorded for US 11,098,908. Google Patents continues to list FH Alliance Inc. as current assignee; anticipated expiration 2036‑10‑21. There is no assignment to any licensing entity, holding company, or aggregator.

Timeline diagram

timeline
    title Ownership of US 11098908
    2012 : FH Alliance founded in Kasugai Japan
    2016 : PCT application filed for the system
    2019 : Inventors assign rights to FH Alliance
    2019 : US national stage published
    2021 : US 11098908 granted to FH Alliance
    2025 : Technology licensed to Panasonic NA

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The patent has never left FH Alliance Inc. There is no assignment to any "IP / Holdings / Licensing / Ventures" entity; the assignee's address is a company premises in Kasugai, Aichi, not a registered‑agent service address; and there is no single‑purpose LLC anywhere in the record. The only recorded conveyance is inventors → operating company.

2. Known asserter in the chain — not present. Neither FH Alliance Inc. nor any other named party appears on the enumerated NPE lists (Acacia, Marathon, IV, IPNav, Wi‑LAN, Conversant/Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, DGC, Spangenberg entities) or on any Unified Patents / RPX high‑frequency‑plaintiff listing I could retrieve. FH Alliance comes up instead as a defendant‑side technology supplier licensing into a Fortune‑500 OEM.

3. Repeat correspondent across the chain — not present. Correspondent of record is Kratz, Quintos & Hanson, LLP. There is only one link in this chain, so the "recurrence across multiple links" test cannot be satisfied by construction. The firm's repeated appearances are across FH Alliance's own commonly‑owned patent family, which is the normal prosecution‑firm pattern for a foreign applicant and not a shell‑entity tell. Single appearance in the chain ⇒ not a finding.

4. Cascading transfers — not present. Zero post‑issuance assignments; therefore no chain of LLC‑to‑LLC transfers in any window, let alone <24 months.

5. Pre-litigation transfer — not present. The only assignment is dated 2019‑02‑12, roughly 2.5 years before grant (2021‑08‑24) and long before any assertion. I found no infringement suit naming US 11,098,908 or FH Alliance as plaintiff in the sources reachable to me. The assignment predates issuance and cannot be a pre‑suit venue/standing transfer.

6. Bankruptcy fire-sale — not present. No Chapter 7/11 proceeding, no patent sale in bankruptcy, no distress transfer involving FH Alliance.

7. Privateering — not present. The Panasonic relationship runs the opposite direction from privateering: FH Alliance is the small operating innovator supplying technology to a large OEM (Panasonic Eco Systems North America → OASYS), rather than an operating company using a proxy to sue competitors. This is an outbound technology‑transfer arrangement, not an enforcement vehicle.

8. Defensive aggregator (anti‑NPE) — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. It terminates at the original operating assignee, which still owns the patent.

Verdict

Insufficient data — with a strong operating‑company overlay.

The assignment record for US 11,098,908 contains exactly one entry: a joint inventor assignment from Kazuro Hiroishi and Hiromi Sugiyama to FH Alliance Inc., recorded 2019‑02‑12 (conveyance: assignment of assignors' interest; corresponding firm Kratz, Quintos & Hanson, LLP; reel/frame not capturable in the sources I could reach). Under the rubric this is the "only the original assignment" case, which is itself the finding — no post‑issuance assignment exists, so the original assignee still owns the patent. Every substantive signal points away from an NPE: FH Alliance is a real, revenue‑generating Japanese manufacturer of whole‑house air‑conditioning systems (MACH system) whose technology was adopted by Panasonic's OASYS product launched 2025‑01‑07, and I found no litigation and no transfer to any licensing vehicle. Accordingly, all eight NPE signals are not present, and zero strong or weak signals are made out.

Verify directly: USPTO Assignment Center — search by patent number 11098908, or by application 16/312,076; the same underlying records are surfaced at https://assignment.uspto.gov/patent/index.html.

Analyst caveats

• The reel/frame number for the sole recorded assignment is missing from my sources. Do not carry any reel/frame for this patent into a memo — I have seen reel 066104/0194 in connection with a different FH Alliance patent family (effective 2023‑12‑11), and that number must not be transposed onto the '908 patent.
• The execution date of the 2019 assignment was not exposed; only the recording date (2019‑02‑12) is confirmed. Google Patents' legal‑events table for this patent shows the 2019‑02‑12 "Assigned to FH ALLIANCE INC." entry and nothing else.
• Hiromi Sugiyama's employer at filing is unconfirmed and is flagged as such rather than asserted.

I'll research the cited prior art for US 11,098,908, starting with the patent's own citation record.

Excellent — I surfaced the actual citation list. Let me drill into each reference and recover the complete cited-reference table.

Let me pull the ISR for the parent PCT application and verify each cited reference.

Prior-art analysis — US 11,098,908 B2

Scope note: this section builds on the earlier "Patent summary" (which flagged that the granted claim set could not be verified). Two things changed in this pass: (a) I recovered the actual cited-reference table for the granted patent, and (b) I recovered the granted claim 1 text, which resolves the earlier "moderate confidence" flag. I did not recover the full text of most of the cited references, and I label that gap rather than filling it from memory.

1. Sources used and their limits

Hard limits I am not papering over:

• I could not reach USPTO Patent Public Search, Patent Center, or Espacenet directly in this session; the citation table below is a secondary-source snapshot (Justia) and may be incomplete or mis-ordered at the margins.
• I could not retrieve the ISR "Box C" (Documents Considered to be Relevant) for PCT/JP2016/081263 / WO 2018/073954 A1, which would carry the examiner's X/Y categorizations. That is the single highest-value artifact still missing (see §6).
• I could not retrieve titles/abstracts for the cited patents. Where I say nothing about a reference's disclosure, that is deliberate — not an assertion that it discloses nothing relevant.

2. Resolution of the earlier claim-set discrepancy (flag)

The earlier summary rated the granted claim set "moderate confidence." The Justia granted-claims text now confirms granted claim 1 is the design method, and it reads (verbatim limits below):

"1. A design method of an air conditioning system comprising a plurality of rooms and a return compartment in a building … an air-conditioning ability determining step … a blast air volume determining step … a total blast air volume calculating step … and an air-conditioning air volume determining step of determining equal to or less than 70% of the total blast air volume … as an optimal air-conditioning air volume … wherein … the at least one air conditioner is capable of setting the optimal air-conditioning air volume … wherein the air is sent from the return compartment to an attic space that ensures airproof and heat insulating properties other than the room inside of the building, the air is circulated from the attic space to the return compartment, and it is added to the total blast air volume."

Consequences:

1. The earlier "moderate confidence" flag on the 70% + attic limitations is now upgraded to confirmed for claim 1.
2. The as-filed construction-method claim 1 (publication claim 1, specification "first aspect") does not appear as granted claim 1. Either it was cancelled, or the claim set was reordered with it appearing later in the granted set. I could only retrieve granted claim 1, so the construction-method claims' fate on grant remains unverified — do not assume they survived.
3. Correction to an earlier section: the earlier strategic summary speculated that "WO2014111061A1/JP-family art indexed in searches" might be usable § 102/§ 103 art. That document appears nowhere in this patent's citation record, and the search hit that surfaced it belonged to a different ISR (Chubu Denryoku / Green Sage / Valeo lineage). Remove it from the candidate art list.

3. The cited-art record for US 11,098,908

3.1 Front-page / "Referenced Cited" (as retrieved)

U.S. Patent Documents

Foreign Patent Documents

Other references / non-patent literature

3.2 Art cited inside the specification (not necessarily on the front page)

• JP 2012-57880 — the specification's own "Patent Document 1," i.e., the applicant's conceded background art (the attic air conditioner chamber 101 with mixing section 133 / dispersing chamber 200 of FIG. 8). This is the only reference whose full disclosure is available to me (through the patent's own description of it).
• Haruo YAMADA, Freezing and air conditioning, Kabushiki Kaisha Yokendo, Mar. 20, 1975, pp. 240–247 — cited in the specification as the source of the air-conditioning load calculation methodology recited in the "air-conditioning ability determining step."
• Caution / possible contradiction: JP 2012-57880 does not appear in the Justia "Referenced Cited" list I retrieved, even though the specification cites it as Patent Document 1. That is anomalous — a § 102(b) / § 102(a) "D" or "A" reference cited in the application normally appears on the front page. Either (i) the Justia snapshot is incomplete, or (ii) the reference was cited only in the text and handled as an IDS item listed elsewhere. Verify against the printed front page.

4. Reference-by-reference § 102 mapping

Methodology and honesty caveat. Anticipation under § 102 requires a single reference to disclose every element of the claim, arranged as claimed. Granted claim 1 requires, in combination: (i) a building with a plurality of rooms and a return compartment; (ii) intake sections in each room; (iii) an exhaust section forming return airflow from each room to the return compartment; (iv) a plurality of blowers and at least one air conditioner located inside the return compartment; (v) four named design steps; (vi) the "≤ 70% of Vh" relationship; and (vii) circulation to an attic space added to Vh. No referenced item on its face supplies (vii), and I have not read the disclosures of the cited documents. The mapping below therefore states which claim element each reference is a plausible target for, not a finding of anticipation. Where I could not verify a disclosure, I say so.

5. Is any cited reference a § 102 anticipation?

On the record retrieved, no. The closest candidate is the applicant's own conceded background art, JP 2012-57880, and it fails at least one express limitation of every independent claim:

• Granted claim 1 requires air sent from the return compartment into an attic space and circulated back, with that air added to the total blast air volume — nothing in the JP 2012-57880 summary recited in the specification does this (its attic is where the AC chamber sits, not a recirculation volume added to Vh).
• As-filed claim 1 requires "a return compartment which is adjacent to a plurality of rooms." JP 2012-57880 places the air-conditioner chamber in an attic — the very configuration the patent characterizes as the problem to be solved ("it is necessary to provide the air conditioner chamber as a chamber for exclusive use"). That difference is the invention's stated point of novelty, and the examiner evidently accepted it.

Everything else in the cited set is either (a) a procedural document (ISR / office actions — not prior art), or (b) art I could not read. The realistic posture is therefore § 103 combination art, not § 102 anticipation.

Practical implication for a defendant: the anticipation case, if one exists, is more likely to sit in uncited art — 2015–2016-vintage Japanese residential whole-house air-conditioning publications (the JP 2015-215107 / JP 2016-033448 window is precisely where such art lives) and in the applicant's later-sibling filings from the same 2016 disclosure (which are not prior art but are useful for showing the breadth of what the applicant itself treated as conventional).

6. Highest-value next step (not completed)

Pull WO 2018/073954 A1 (the international publication of PCT/JP2016/081263) and read its ISR Box C. That page carries the examiner's X / Y / A designations and the specific passage citations (paragraph and figure numbers) for the patent documents listed in § 3.1. It is the fastest way to convert the table above from "plausible target" into "asserted disclosure," and it will also reveal whether any reference was designated X (i.e., a standalone novelty attack). Retrieval targets:

• https://www.wipo.int/patentscope/ — search WO2018073954
• https://patents.google.com/patent/WO2018073954A1/en
• The JP 2018-546120 Decision of Refusal (Jun. 29, 2020) and the CN 201680086887.8 OA (May 29, 2020) listed in the record — both would name the examiner's blocking art with citations.

7. Disambiguation warnings (carried forward and reinforced)

1. The literal string "11098908" is a poor search key. Outside patent databases its only hit is an unrelated Brazilian commercial-registry entry (JUCEPAR / DOMINUS INDÚSTRIA). Not relevant.
2. My search results also surfaced a PTAB petition exhibit discussing "Newton" (Ex. 1007) and "Shimizu" (Ex. 1008, U.S. Pat. No. 5,317,907). That petition does not involve US 11,098,908 — do not conflate it with this patent's art. Note the near-miss number: 5,317,907 (Shimizu) vs. this patent's cited 5,314,376 (Kuramarohit). Different patents.
3. Do not transpose JP 6857303 B2, US 11,441,796, US 11,906,198, or CN 109477647 B into the prior-art column — they are same-family / same-priority members, not prior art against the 2016-10-21 priority date.

8. Bottom line

• Citation record retrieved and tabled (2 US patents, 7 foreign patent documents, 3 NPL/procedural items), anchored to Justia's page for the granted patent.
• Most relevant prior art, ranked: (1) JP 2012-57880 — applicant-admitted background art, the only reference with a verified disclosure, targeted at as-filed construction claims 1–7 and § 103 against the overall architecture; (2) U.S. DOE "HVAC Right-Sizing Part 1" (2011) and the Yamada (1975) text, both targeting the design-method steps of granted claim 1; (3) Lu Handbook targeting the per-room air-volume step; (4) JP 2016-033448 (Mar. 2016) and JP 2015-215107 (Dec. 2015) as the nearest-in-time cited art whose content I could not verify; (5) US 3,169,382 (1965) and US 5,314,376 (1994) as date-qualified structural art whose content I could not verify.
• No § 102 anticipation is supportable on the retrieved record, and I have explicitly not asserted disclosures for the nine references I could not read.
• Confirm the front page and the ISR Box C before relying on any of this in an invalidity contention or an IDS.

I'll ground this obviousness analysis in actual prior art. Let me pull the references cited on the face of the patent and search for analogous art.

Obviousness Analysis — US 11,098,908 B2 under 35 U.S.C. § 103

Patent: Construction method and design method of an air-conditioning system
Assignee: FH Alliance Inc. · Priority/filing: 2016‑10‑21 · Grant: 2021‑08‑24 · Expiry: 2036‑10‑21

0. Threshold caveats (carried forward and expanded)

Two limitations from the previously generated sections constrain everything below, and I will not paper over them:

1. Claim-set uncertainty is unresolved. The granted claim text could not be read from the primary source (the Google Patents fetch in the record truncates before the claims). The spec's "first aspect" through "tenth aspect" track the as-filed claims. The Justia-derived granted claim 1 appears to differ (70 % limitation and attic-space recitation moved into claim 1). Accordingly, I analyze § 103 against three variants: (a) the as-filed construction-method claim; (b) the as-filed design-method claim; (c) the Justia-derived granted claim 1 (design method + ≤70 % Vh + attic circulation). The obviousness conclusion is the same for all three, but for different reasons, and each is stated separately.

2. Contradiction flagged — WO2014111061A1. A prior section's "recommended next steps" listed "WO2014111061A1/JP-family art" as a candidate § 102/§ 103 reference. My search of that document (https://patents.google.com/patent/WO2014111061A1/en) shows it is titled "Hot and cold inner balancer set" — a water-side heat/cold balancer (compressor, plate heat exchangers, solenoid valves), classified F25B 29/00 / F25B 1/00 / F25B 5/04 / F25B 6/04, filed WOCN2014071003 (2014‑01‑21). It has no bearing on residential air distribution, return compartments, or blower/air-conditioner sizing. Disregard that suggestion; it does not belong in any obviousness ground.

3. JP 2012‑57880 was not directly retrievable in this session. I could not open the reference itself. All characterization of it below is taken from the applicant's own description in the patent's Background — which is the stronger evidentiary posture, because under MPEP § 2129 / In re Nomiya an applicant's admission about the prior art in the specification is usable as prior art against its own claims. I flag it so a real petition would attach the reference's own figures and paragraphs ([0001]–, FIG. 8).

1. Legal framework applied

Graham v. John Deere Co., 383 U.S. 1 (1966) (scope/content of prior art; differences; PHOSITA level; secondary considerations), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (motivation may be supplied by "the nature of the problem," the prior art's own teachings, common sense, and design incentives; predictable combinations are obvious; "obvious to try" applies to a finite set of identified, predictable solutions). Rationales are articulated in MPEP § 2143 categories: (A) known elements combined by known methods to yield predictable results; (B) simple substitution of one known element for another; (D) applying a known technique to a known device ready for improvement; (F) obvious to try.

PHOSITA definition I apply: a mechanical/residential-HVAC engineer (or an HVAC design-build technician) with ~3–5 years of experience in residential air-distribution design and in whole-house ("全館空調") systems, familiar with ASHRAE load calculation, room-by-room airflow sizing, duct design, and air-diffusion/return-path principles. This mirrors the art level the patent itself assumes — it cites a 1975 textbook (Haruo YAMADA, "Freezing and air conditioning," K.K. Yokendo, Mar. 20, 1975, pp. 240–247) for the load-calc step.

2. The prior art

(Caveat on [PR‑5]: retrieved as a search result; I did not obtain its full text or verify its applicant. Treat its bibliographic details as needing confirmation via J‑PlatPat before filing.)

3. Variant (a): the construction-method claim

Claim elements and mapping.

Why the difference is obvious. The sole delta is where the plenum is: a purpose-built attic chamber ([PR‑1]) versus an existing staircase/corridor ([PR‑2]). That is a textbook MPEP 2143 rationale (B): substitution of one known element (an existing architectural circulation volume) for another (a built chamber) to obtain the predictable result of housing equipment and mixing return air. The motivation is supplied by the nature of the problem the applicant itself identifies: PR‑1 requires a dedicated chamber, which the applicant admits is "not easy to construct" and requires "a certain size of capacity." A PHOSITA seeking to avoid that construction cost would look first to spaces that already exist, are already adjacent to the served rooms, and already connect them — staircases and corridors. The patent's own specification confirms these spaces are adequate (staircase capacity "about 16.2 m³"; "capacity of a general stair case is sufficient as capacity of the return compartment"), i.e., the selection is a design choice among a finite, predictable set of candidate volumes.

Secondary limitations (dependent claims / "aspects") are each independently routine:

• Blower suction port avoids / is below the AC spout port; AC spouts substantially horizontally (±15° down) — [PR‑3], combined by rationale (D): applying the known short-circuit-avoidance design rule to the newly-relocated equipment. A wall-mounted split unit already has its intake on the top surface and its discharge at the lower front (spec's own description of AC 30a: suction port in "upper surface 31," spout port in "a lower portion of a front surface"). Placing the recirculating blowers' intakes elsewhere on the same wall is geometry, not invention.
• At least one exhaust section above the air conditioner — [PR‑1] + [PR‑3]: high-level return grilles feeding a unit whose intake is at the top is the canonical arrangement; PR‑1's louver-in-floor at the base of the chamber is the same return path moved one storey.
• Total blast volume of the blowers > air-conditioning air volume of the AC — this is simply the arithmetic consequence of a partial-flow air handler inside a larger circulation loop, a configuration long known in fan-powered/recirculating terminals ([PR‑2]/[PR‑3]). It is also, on the patent's own numbers, an inevitable equilibrium condition (700 m³/h AC vs. 1,200 m³/h blowers), not an inventive selection.

Conclusion (a): Claim 1 and its dependents are obvious over [PR‑1] in view of [PR‑2] and [PR‑3], with rationales (B) and (D).

4. Variant (b): the design-method claim

The four ordered steps are:

1. Air-conditioning ability determining step — compute building load, pick AC capacity.
2. Blast air volume determining step — per-room supply air from room capacity.
3. Total blast air volume calculating step — sum to Vh.
4. Air-conditioning air volume determining step — derive Vq from Vh; then select blowers from step 2 and an AC having step‑1 capacity and capable of setting a volume ≤ Vq.

Every step is standard engineering practice, and the patent says so itself. The applicant expressly sources step 1 to [PR‑4] (Haruo Yamada 1975, pp. 240–247) and then adds only the caveat "More room is given to this load calculation result" — i.e., a safety margin. Step 2 is the routine per-room airflow derived from room size/load; the spec's own figures ("preferably at least 13 m³/h or more per 2.5 m³ of the room and ideally, about 20 m³/h") are an air-change rule of thumb, the kind of number found in every residential HVAC design guide. Step 3 is a sum. Step 4 is a comparison of two numbers already computed.

Under KSR, "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions." Here the only arguable contribution is the ordering and the comparison, i.e., a method of using published load-calc and airflow-sizing rules to select equipment from a vendor lineup. That is the definition of a predictable, routine engineering workflow — rationale (A).

The as-filed dependent "air volume adjustment means" limitation (notch switch changing fan rpm, or a shutter adjusting grill opening area) is disclosed or rendered obvious by ordinary ventilation equipment — multi-tap/notch-speed fans are ubiquitous, and the spec describes the mechanism in one sentence as an off-the-shelf item.

Conclusion (b): The design-method claim is obvious over [PR‑4] in view of [PR‑1] and [PR‑2]/[PR‑3] (routine design steps), with the strongest single combination being [PR‑4] + [PR‑1] + the ordinary skill of the residential-HVAC designer — because PR‑1 supplies the very system being designed and [PR‑4] supplies the calculation method the claim recites.

5. Variant (c): the Justia-derived granted claim 1 (≤70 % Vh + attic circulation)

If the granted claim 1 indeed recites (i) "the optimal air-conditioning air volume is equal to or less than 70 % of the total blast air volume," and (ii) sending air from the return compartment into an attic space (airproof/heat-insulated, outside the rooms), returning it to the return compartment, and adding it to the total blast air volume, then:

• The attic-space element is disclosed by the applicant's own admitted prior art. [PR‑1] has an "attic air suction port 400" and an "outside air introduction port 311" on the chamber wall, both of which draw attic air into the chamber where the air conditioner and blowers sit. Sending conditioned air to the attic and back is the mirror image of PR‑1's own attic-to-chamber path, executed for the same purpose (enlarge the circulating loop / temper the attic). Rationale (B).
• The 70 % relationship — i.e., deliberately inflating Vh so that the AC's lowest settable volume is a small fraction of total system flow — is the known turndown problem with a known fix. [PR‑5] addresses exactly this: a system blower with a minimum air volume Gm that cannot be reduced further, solved by branching a duct to a non-conditioned space (a corridor) so the system keeps moving air. That is functionally the same maneuver as the patent's "add ~300 m³/h of underfloor supply so 700 m³/h becomes 46 % of Vh." A PHOSITA facing the minimum-speed floor of a residential split unit's fan — a well-known constraint, since indoor units are sold in discrete fan steps (strong/intermediate/weak) — would, with a reasonable expectation of success, add bypass/relief flow to non-critical space. Rationales (D) and (F).
• The dependent "≤70 % and select the blower such that the AC's minimum settable volume is ≤70 % of Vh" is the same analysis with the inequality reversed; no new art is needed.

Conclusion (c): Also obvious. Note the internal-consistency problem the applicant created: the spec says that at light load with an inverter compressor "there is no problem even if the total blast air volume Vh is decreased and the air-conditioning air volume becomes 70 % or more of the total blast air volume Vh" — an express admission that the 70 % boundary, and even exceeding it, is not critical.

6. Motivation to combine — articulated per MPEP 2143

1. From the problem itself (KSR). The applicant frames the problem as: a dedicated AC chamber is required, and AC/exhaust/supply are crowded together causing short-circuiting. Relocating the equipment into an existing, larger, already-connected circulation volume (staircase/corridor) solves both. The prior art need not suggest the invention; it need only render the solution predictable.
2. Design incentive / cost. Avoiding construction of a purpose-built chamber is an economic motivation of the kind KSR recognizes.
3. A finite, predictable set of options. The candidate return plenums are enumerable (attic chamber [PR‑1], staircase, corridor, ceiling plenum, underfloor) and their relative merits known — the definition of "obvious to try."
4. Same field, same function. All references are in CPC F24F and concern supplying conditioned air to multiple rooms from one central unit. [PR‑1] and [PR‑5] are analogous art rendering the art as a whole suggestive of the claimed subject matter (In re Keller).
5. Predictable result. The claimed benefit — mixing the unit's discharge with returning room air so that supply air temperature differs less from room temperature — is exactly what PR‑1's mixing section 133 was already built to do. Removing the wall (106) and letting the building itself be the mixing section is a predictable simplification.

7. Defenses the patent owner will raise, and vulnerabilities

8. Bottom line and confidence

Verdict: on the record available, US 11,098,908 is vulnerable to a § 103 challenge on all three analyzed claim variants, with the strongest single ground being [PR‑1] (admitted prior art, JP 2012‑57880) in view of [PR‑2]/[PR‑3] (return plenums through existing circulation spaces + standard short-circuit-avoidance diffusion practice) — the entire inventive distance being the substitution of a staircase/corridor for a purpose-built attic chamber, a substitution the applicant's own specification characterizes as adequate and the prior art renders predictable. Success on the design-method variant requires adding [PR‑4] (the admitted load-calc text) and, for the ≤70 % limitation, [PR‑5] or equivalent turndown/bypass art.

Confidence levels:

• High — that [PR‑1] discloses all structural elements of the construction method except "staircase/corridor," and that the specification's own admissions (dedicated chamber "not easy to construct"; "capacity of a general stair case is sufficient") supply the motivation for the substitution.
• High — that the design-method steps are routine engineering in view of the applicant's own cited textbook.
• Moderate — the [PR‑5]-based ground for the ≤70 % limitation; I retrieved the document but did not verify its full text or applicant.
• Low / needs work — the [PR‑3] "general knowledge" ground. General-knowledge assertions draw In re Kahn/KSR scrutiny and require documentary support.

Verification steps before any filing or opinion:

1. Pull the printed granted claims (USPTO Patent Public Search, https://ppubs.uspto.gov/, or Patent Center for App. 16/312,076) to fix the claim set and resolve the Justia-vs-publication discrepancy flagged in the earlier summary.
2. Obtain JP 2012‑57880 A full text and figures (J‑PlatPat / Espacenet) to convert the § 2129 admission into direct citation of paragraphs and drawings.
3. Corroborate [PR‑3] with a documentary reference — ASHRAE Handbook—Fundamentals, "Space Air Diffusion," and ASHRAE Handbook—HVAC Systems and Equipment, "Air Distribution," plus a corridor-return (hotel/dormitory) design source — so the ground is not general-knowledge-only.
4. Verify JP 2013‑104578 A bibliographic data and locate at least one additional bypass/relief-air reference for the turndown limitation.
5. Note the § 315(b) one-year clock is not yet running (no complaint identified in the earlier litigation section); the earlier sections found no PTAB proceeding and no litigation, so no estoppel exists and this is a clean-slate, one-shot opportunity — any petition should be filed comprehensively.