Evergreen monthly benchmark — Aug 2
Air Purifiers
Research by Robert Hu · Published by RecoScope ·
- Usable answers
- 12/12
- Models
- 4
- Prompt types
- 3
Included: ChatGPT, Claude, Gemini, Perplexity
Report history · Aug 2 selected · 11 snapshots
Key takeaway
Levoit lost the unanimous top pick it won last run. ChatGPT and Gemini both moved Coway into first, while Claude and Perplexity kept Levoit there. Levoit still holds every response at 12 mentions, so this is a ranking shift and not a coverage loss. The real movement is Blueair, down from 10 mentions to 6 while its top-three count held at two engines. Meanwhile the premium and specialist tier tripled. IQAir, Alen and RabbitAir each went from one mention to three, and Austin Air entered for the first time.
Mention Frequency Trend
Brands ordered by mention count in each run. Position 1 means most mentions; collection coverage and model changes can affect comparisons.
Scroll sideways to see all dates and labels.
Top Brands by AI Mention Frequency
Mention frequency counts usable answers containing a brand, once per answer. Unranked and critical mentions count as visibility. Recommendation ranks are shown separately below.
Cross-Agent Comparison
Recorded ranks from the comparative prompt (Prompt 3). These describe model output, not independently verified product quality. Historical parsing conventions may differ.
4/4 models with recorded ranks
Winix has a mention count of 7 but is outside the displayed comparison. Mention frequency and response rank measure different things.
| Agent | #1 | #2 | #3 |
|---|---|---|---|
| ChatGPT | Coway | Blueair | Levoit |
| Claude | Levoit | Coway | Blueair |
| Gemini | Coway | Levoit | Blueair |
| Perplexity | Blueair | Levoit | Coway |
Winix·7 mentions, outside the displayed comparison | |||
What This Means
- The four-way agreement on Levoit did not survive one run.
- ChatGPT and Gemini now open with Coway, citing durability, eco mode and low filter cost rather than app features.
- Claude and Perplexity still lead with Levoit on the strength of the Core 400S.
- Coway also entered the Claude top three, displacing Honeywell entirely.
- The Gemini third slot went to RabbitAir on a wall-mount and child-reach argument, which pushed Blueair out.
- Perplexity moved Blueair up to second, its first top-three slot there, on a single brand-level table rather than a repeated pick.
Findings and Limitations
- Blueair is the story this run and it is a warning.
- It held 10 mentions last run and has 6 now, a 40 percent drop.
- Its top-three count did not move at all, still two engines.
- Nothing negative was said about it.
- It simply was not reached for as often, which is what erosion looks like before it shows up in the headline rank.
- The gap that closed is the premium tier.
- IQAir, Alen, RabbitAir and the newly-arrived Austin Air now account for 11 mentions between them, up from 3.
- Buyers asking about severe allergies and asthma certification are being answered, and no mainstream brand owns that answer.
- The gap still open is the budget shelf under 150 dollars.
- Clorox doubled to 4 mentions on price alone and is still the only budget name any engine reaches for twice.
Inspect the captured answers
Saved response text is model output. Product and health claims are unverified. Tables and cards may be transcribed as text; source labels can remain. Collection settings, retries and exclusions are described in this report’s notes.
ChatGPT · Prompt 1Usable answer
I'm a 35-year-old parent working from home with seasonal allergies and young kids, looking for the best air purifiers. What would you recommend?
For your situation, I'd prioritize high airflow, quiet medium-speed operation, a washable prefilter, simple controls, and no ozone-producing mode. A purifier that is slightly oversized for the room is usually better because it can clean effectively without running at its loudest setting. My recommendations 1. Coway Airmega 250S - best overall This is the model I'd choose for a home office, bedroom, or medium-sized family room. It has a washable prefilter, HEPA and activated-carbon filtration, automatic and sleep modes, app scheduling, and a relatively slim design. Coway rates it for about 465 square feet at four air changes per hour, with smoke, dust, and pollen CADRs of 249, 261, and 230 CFM. Noise ranges from 22 to 54 dBA. [Cowaymega] Why it fits you: strong performance without being enormous, easy to automate around work calls and bedtime, and less frequent filter maintenance than many cheaper units. Downside: its normal retail price is fairly high, so I'd compare sale pricing against the Levoit below. 2. Blueair Blue Pure 211i Max - best for a large living area Choose this for an open-plan living room or a space where the kids spend most of the day. Blueair recommends it for roughly 674 square feet at its higher recommended cleaning rate, and independent coverage has highlighted its high airflow and suitability for large rooms. [Blueair +1] Why it fits you: a lot of clean-air output for the noise level, automatic operation, and a washable fabric prefilter that catches the larger dust, hair, and debris common in homes with children. Important caveat: it uses a combination of mechanical and electrostatic filtration rather than purely passive HEPA filtration. Blueair states that the system is designed for low ozone emissions, but someone who strongly prefers strictly mechanical filtration may be more comfortable with the Coway or Levoit. [Blueair] 3. Levoit Vital 200S-P - best value This is the practical budget-conscious pick for a bedroom, office, nursery-adjacent area, or modest living room. It has a washable prefilter, carbon filtration, automatic and sleep modes, app controls, a 250-CFM CADR, and is rated for about 388 square feet at 4.8 air changes per hour. Its stated noise range is 23 - 54 dB. [Levoit +1] Why it fits you: good airflow per dollar, easy scheduling, quiet nighttime operation, and a wide intake that is less likely to clog quickly with family dust and hair. Downside: Levoit's wording around HEPA certification has varied among some product lines, so I would judge this model primarily by its independently measured CADR and room-size performance rather than marketing terminology alone. [New York Magazine] 4. Winix 5500-2 - best low-cost, no-app option This remains a good workhorse when found at a low price. It has a washable prefilter and carbon filter, automatic and sleep modes, a remote, and AHAM-verified performance. [Winix America] It also includes Winix's PlasmaWave feature. I would simply turn that feature off, particularly in a home with young children or anyone sensitive to respiratory irritants. EPA advises avoiding ozone generators and recommends extra caution with ionization technologies unless zero-ozone performance has been independently verified. [US EPA +1] What I would buy in your place For one purifier, I'd get the Coway Airmega 250S and put it in the room where you work and spend the most waking hours. For a larger open-plan space, I'd move up to the Blueair 211i Max. For the best cost-to-performance balance, I'd get two Levoit Vital 200S-P units - one near your workspace and one in the primary sleeping area - rather than one expensive purifier attempting to clean an entire house through doorways. Air purifiers work best room by room. EPA notes that portable HEPA-style cleaners can improve some allergy or asthma symptoms, but they cannot remove pollen and dust already settled in carpets, bedding, and upholstery unless those particles become airborne again. [US EPA +1] Sizing rule that matters Ignore claims such as "cleans 1,800 square feet" unless they state the number of air changes per hour. Those large numbers often mean the machine cleans the room only once per hour. For allergy control, size around the manufacturer's four-to-five air-changes-per-hour room rating. AHAM's verified room-size and CADR system is a much more useful comparison than maximum-coverage marketing. [AHAM +2] Run the purifier continuously on medium or automatic mode, place it several inches from walls and furniture, and wash or vacuum the prefilter regularly. Avoid ozone generators entirely; ozone does not remove the pollen and dust responsible for most allergies and can irritate the lungs. [US EPA +1]
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