About · Methodology
How we rank portable home air purifiers
Best Air Purifiers Ranked covers Portable HOME air purifiers (room air cleaners) only. Not portable air conditioners, not mini-splits, not whole-home HVAC. Domain: best-air-purifier-ranked.com. Last data review: 2026-10-27. Corrections: corrections@best-air-purifier-ranked.com.
Lexicographic ranking
- CADR effectiveness for stated room size — prefer AHAM Verifide smoke / dust / pollen CADR. Scored as CADR tiers from smoke CADR (and matching AHAM room size ≈ smoke × 1.55 at ~4.8 ACH). Marketing “covers 1,500 sq ft” claims at 1–2 ACH are never used. No published CADR →
rank: null(unranked). - Filter quality — score 3 True HEPA/H13 + carbon in the standard filter; 2 True HEPA with optional carbon or non-True-HEPA with carbon (e.g. HEPASilent); 1 HEPA-type / unverified; 0 unknown.
- Tie-break — ENERGY STAR certified first (null treated as not certified) → AHAM Verifide listing → higher smoke CADR. Noise is noted in copy only when a source publishes dB.
| Tier | AHAM room size | Smoke CADR |
|---|---|---|
| 5 | ≥ 600 sq ft | ≥ 387 |
| 4 | 450–599 | 290–386 |
| 3 | 300–449 | 194–289 |
| 2 | 200–299 | 129–193 |
| 1 | < 200 | < 129 |
CADR source priority: AHAM Verifide directory → ENERGY STAR Room Air Cleaners V3.0 → manufacturer. Conflicts are logged in product notes; we do not invent numbers.
Full rule text: src/data/ranking-rule.md. Dataset: src/data/products.json. Sort helpers: src/lib/ranking.ts.
CADR and AHAM’s 2/3 rule
Clean Air Delivery Rate (CADR) is the volume of filtered air delivered for tobacco smoke, dust, and pollen. Higher CADR means faster cleaning for that particle class. AHAM Verifide publishes independently tested CADR and a suggested room size (≈ smoke CADR × 1.55 for ~4.8 ACH).
AHAM 2/3 rule: choose a unit whose tobacco-smoke CADR is at least two-thirds of the room’s area in square feet. Example: a 10′ × 12′ room (120 sq ft) needs smoke CADR ≥ 80. If ceilings are taller than 8′, size up.
Directory: ahamdir.com room air cleaners.
Independence & affiliates
Affiliate status never changes rank. Zero paid placements. As an Amazon Associate I earn from qualifying purchases. Amazon Associate tags are placeholders in src/data/site.ts: PLACEHOLDER_US_TAG / PLACEHOLDER_UK_TAG. Marketplace helpers match US vs UK hosts and tags in src/lib/amazon.ts.
Data policy
Every CADR, AHAM, ENERGY STAR, and noise field may be null. Product pages link sources[]. IQAir and Dyson rows without published CADR stay unranked. Ionizers are flagged in notes, not scored.