Desk research only. No hands-on testing was performed by Filter Math. All social evidence is paraphrased, never quoted verbatim. Health-adjacent claims appear only as attributed owner/reviewer accounts, never as proven medical efficacy. Marketplace prices are asking prices, not completed sales. All time-sensitive facts and prices dated 2026-09-23 unless otherwise noted. UNVERIFIED marks facts that could not be confirmed from a recovered source. Seed-file attributions (market-selection file) were treated as leads, not citations; claims from it were not reused without independent recovery.

1. Disclosure

This dossier was built from Amazon comparison listings, a filter-cost comparison site (ralphsway), and spec aggregators, observed 2026-09-23, plus limited social-tool access. Social discovery was attempted via Threads CLI, Facebook CLI, and Instagram CLI on 2026-09-23; direct owner posts for this model were not recovered. The 5520 has the thinnest independent-tester footprint of the Winix smart pair — most measured data in the sample belongs to the 5510. Where the seed market-selection file named a source without a URL, that claim was treated as a lead and is not cited here unless independently recovered (see private source ledger _source-ledger.md, which never ships).

2. Overview / current version

The Winix 5520 is the 5510's smart sibling: the same CADR band (252 dust / 247 pollen / 253 smoke per Amazon's comparison listing), Wi-Fi/app/Alexa/Google, auto mode, filter indicator, HEPA + carbon + PlasmaWave. Public documentation does not draw a sharp feature line between the 5510 and 5520 in the recovered sample — they are listed with identical headline specs, suggesting regional/bundle/retailer differentiation rather than a performance tier. Do not invent a difference between them.

3. Social standing & validation tier

UNVALIDATED — included for comparison, low community signal.

  • No Threads, Instagram, or Facebook owner posts specific to the 5520 were directly observed in Filter Math's session (Threads search attempted 2026-09-23; Facebook groups search failed with a connector grant error — access failure, not no-results).
  • No dedicated independent measured review of the 5520 was recovered; coverage is listing- and aggregator-level.

4. Specs

SpecValue
CADR252 dust / 247 pollen / 253 smoke (Amazon comparison listing — same ordering caveat as the 5510; sources conflict)
Room coverage1,882 ft² at 1 ACH (Amazon); ~392 ft² at 4.8 ACH by transparent calculation
NoiseUNVERIFIED for the 5520 specifically (the 5510's measured 35.2–67.2 dBA is not assumed to transfer)
PowerUNVERIFIED for the 5520 specifically
FiltrationTrue HEPA, carbon, PlasmaWave
Smart featuresWi-Fi, app, Alexa/Google voice, auto mode, filter indicator
Filter lifeUNVERIFIED (assumed 12 months by analogy to the 5510 — do not rely on this)

5. Price observed 2026-09-23

6. Annual filter cost

  • ~$70–90/yr — ralphsway comparison figure (observed 2026-09-23), recorded as their estimate. No genuine-filter SKU price was confirmed on 2026-09-23.

7. Included / needed

  • In the box (per standard retail listings): purifier with filter set installed. App setup for smart features. Replacement filter sets are the recurring need. PlasmaWave can be disabled (per Winix's standard implementation; reviewer-noted on sibling models).

8. Support & warranty

  • UNVERIFIED in the documented sample.

9. Attributed owner / reviewer complaints

  • No 5520-specific complaints recovered. The applicable brand-level notes (from the shared ledger's recovered AnandTech thread — snippet-derived from search index, not direct post access — critical of PlasmaWave's value and Winix QC/support) are Winix-general, not 5520-specific. Paraphrased only; do not present as 5520 owner reports.

10. Cross-brand comparison notes

  • The honest comparison for the 5520 is the 5510: identical headline specs in the recovered sample, with the 5510 carrying all the measured data (HouseFresh noise/power, $79.99/yr genuine filter). Against the Coway Mighty2, the ledger-recovered HouseFresh comparator claim groups the 5510/5520 together (with the page-load caveat documented in the Mighty2 dossier). The 5520's value proposition vs. the 5510 cannot be assessed from the documented sample — price and measured performance for the 5520 itself are missing.

11. Community verdict

The least-evidenced dossier in the corpus: listing-level specs, one filter-cost estimate, no measured review, no owner posts. Included for comparison completeness because the fixed item list names it; every substantive figure beyond the Amazon headline specs is UNVERIFIED.

12. Sources (dated)

SourceObservedSupports
https://www.amazon.com/dp/B0DJG1731C/ref=cm_sw_r_cso_fm_apin_dp_H76EBF9KW50452Q3DXFZ2026-09-23 (search snippet)Listing existence; 5520 as distinct SKU
Amazon comparison listing (5510/5520 pair)2026-09-23 (search snippet)252/247/253 CADR; 1,882 ft² at 1 ACH; Wi-Fi/app/Alexa/Google; auto; filter indicator; HEPA/carbon/PlasmaWave
ralphsway (filter-cost comparison)2026-09-23 (search snippet)~$70–90/yr filter estimate

13. UNVERIFIED / open gaps

  • Current US unit price: UNVERIFIED.
  • Measured noise, power, coverage: UNVERIFIED (5510 figures not transferred).
  • Genuine filter SKU, price, and life: UNVERIFIED beyond the $70–90/yr estimate.
  • 5510-vs-5520 differentiation: UNVERIFIED — no documented difference found.
  • Warranty/support terms: UNVERIFIED.
  • Direct owner posts and dedicated measured reviews: not found in the documented sample.