Best negative ion air purifiers for home use

Top pick: Ionbox 20m. It's the most complete home unit here — 20 million negative ions per second, stated zero ozone, coverage up to 500 sq ft, and a quiet 28 dB fan, so it suits a living room or bedroom rather than just a desk.

• Wein Vortex VI-3500 — best for a bedroom or bedside: no motor noise at all, no detectable ozone, compact and filterless.
• Clarifion Air Ionizer (3-pack) — best if you'd rather scatter small plug-ins through several rooms; no coverage rating given.
• Clarifion 6-pack — the same approach for a whole house.
• TALLDU plug-in — a cheap way to try ions in one small room; its coverage is limited.

Worth knowing: these are ionizers, not filters — none has a HEPA filter, so pair one with a filtered purifier if dust or pollen is the main problem. Skip the Sharper Image listing, which reads as a bare generator component, and the near-duplicate second Wein listing.