Winix AT41 Review
The most certified air of any mid-price machine we cover, and the one unit on this site whose paperwork argues with itself. We do not test units, and this page says what that means.
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The most certified air of any mid-price machine on this site — 265 CFM of smoke CADR across 410 certified square feet, on 272 kWh a year, with 0.00 ppb of measured ozone. And one contradiction we are obliged to report: both certification registers classify it fan-and-filter, while Winix’s own manual documents a PlasmaWave button on it.
A note on what this page is, before the numbers. This site owns no air purifiers and runs no laboratory. Nothing below is a measurement we took. It is the certified record for this machine read out of two public registers, set against everything its manufacturer publishes, with the gaps named rather than filled.
The certified record
| Figure | Source | |
|---|---|---|
| Smoke CADR | 265 CFM | AHAM VERIFIDE |
| Dust / pollen CADR | 259 / 244 CFM | AHAM VERIFIDE |
| PM2.5 CADR | 261 CFM | AHAM VERIFIDE |
| Certified room, 4.8 ACH | 410 sq ft | AHAM VERIFIDE |
| Annual energy | 272 kWh | AHAM VERIFIDE |
| Air per watt | 5.6 CFM/W | AHAM VERIFIDE |
| Draw at the test setting | 45 W | AHAM VERIFIDE |
| Measured ozone | 0.00 ppb | ENERGY STAR, on the AT40 |
| Filter classification | HEPA-Type | ENERGY STAR |
| Filter classification | HEPA + Carbon | AHAM VERIFIDE |
| Technology | Fan with Filter / Fan and Filter | Both registers |
| Advanced technology | PlasmaWave | Winix AT40 specification |
| Noise | 22.04 dB minimum | Winix, a minimum only |
| Replacement filter | Filter Z (1712-0121-00), $60, 12 months | Winix |
| Marketing coverage | 1,968 sq ft at 1 air change per hour | Winix |
| Size and weight | 10.24 x 10.24 x 19 in, 10.2 lb | Winix |
Read plainly, that is a strong record. 265 CFM is more certified air than any other mid-price machine on this site, the 410 square feet it is certified for is the largest in that bracket, and 5.6 CFM per watt is respectable for the output. Under AHAM’s two-thirds rule it genuinely covers about 397 square feet at an eight-foot ceiling, and at the 6 air changes an hour this site uses for a home with animals in it, about 331.
The contradiction, which is the reason to read this page
This site has recommended the AT41 more often than any other machine, and part of the reason given was that it carries no ion generator. On 2026-11-07 we read Winix’s own documentation for this platform properly for the first time, and that reason does not survive.
What each source actually says:
| Source | What it records |
|---|---|
| AHAM VERIFIDE | Calculated model type: Fan with Filter. No ion generator recorded. |
| ENERGY STAR | Technology type: Fan and Filter, on the AT40 record. Measured ozone 0.00 ppb. The same register writes 'Fan and Filter, PlasmaWave' for the Winix T810, so it does distinguish. |
| Winix AT40 specification page | Lists PlasmaWave under Advanced Technologies, and names it the fourth of four filtration stages. |
| Winix AT40 / AT41 user manual | Documents a PlasmaWave button that 'enables or disables PlasmaWave technology', and warns of a chirping or buzzing sound 'caused by particles passing through the PlasmaWave system'. |
| Winix AT40 page, footnote | 'The 8-hr TWA Ozone for this product is 0.12 ppbv when tested in a 30 m3 chamber.' |
The honest reading is that there is a PlasmaWave stage, that Winix treats it as a feature, and that neither register records it. A manufacturer does not put a dedicated button on the control panel, warn you about the noise the stage makes, and publish an eight-hour time-weighted ozone figure for a machine that has no such stage.
Two things make that less alarming than it sounds. The first is that Winix documents it as switchable — one button, on or off, exactly as on the 5500-2 line. The second is that the measurements are small in both directions: ENERGY STAR measured 0.00 ppb on this platform, Winix publishes 0.12 ppbv as an eight-hour average in its own chamber, and the manual states the unit complies with a 0.050 parts-per-million ceiling. For scale, the ENERGY STAR program limit is 50 ppb and Winix’s own T810 measures 1.35 ppb.
We have corrected every page on this site that described the AT41 as having no ion generator. The machine’s ranking has not changed, because the reasons it ranks — the certified output, the certified room, the measured zero on the register, the running cost — are all still true. What changed is the justification, and a justification that is wrong is worth more to fix than a ranking that is right.
What it genuinely gets right
The output, and the honesty about the output. Winix advertises 1,968 square feet, which is the usual one-air-change-per-hour inflation. But the same specification page prints the AHAM figure of 410 square feet beside it and names the 4.8 clean air changes per hour the certified figure assumes. Do the arithmetic and the two reconcile exactly. Very little of this category shows its working like that — why the coverage number on the box is usually four or five times the real one.
Carbon that a register will confirm. AHAM records this unit’s filter as HEPA + Carbon rather than HEPA alone, which is a stronger statement about the odor stage than most manufacturers can get a register to make — what carbon does and does not do for pet smell.
A bill you can add up. Winix publishes a price for the Filter Z cartridge and a twelve-month life for both its HEPA and its carbon layer. Combined with the certified energy figure, that makes the AT41 one of only four machines on this site whose whole annual cost of ownership can be stated rather than guessed.
The whole annual bill
| Per year | |
|---|---|
| Electricity (272 certified kWh) | $50 |
| Filter Z (1712-0121-00), one per year | $60 |
| Total | $110 |
Electricity costs on this page use 18.34¢ per kWh, the U.S. average residential price for June 2026 from the U.S. Energy Information Administration, Electric Power Monthly, Table 5.3. Your rate is on your bill and is probably not this one; multiply the kWh figure by your own rate and you have your number.
One retail wrinkle worth knowing. The AT40 offer we checked ships with two complete filter sets, advertised as up to two years of filtration; the AT41 offer we checked does not. Same certified machine, different box. If the two are close on price, that spare cartridge is worth $60 of the first-year bill above.
Where it is beaten, and what Winix leaves blank
Efficiency. 5.6 CFM per watt is fine, not exceptional. The Honeywell HPA4300 does 229 CFM at 7.4 CFM per watt — $34 a year against $50 — with its filter recorded HEPA rather than HEPA-Type, and no source anywhere suggesting an ion stage. For a machine that runs continuously in a smaller room, that is the better buy.
The noise figure is not really a figure. Winix publishes 22.04 dB minimum and nothing else. A minimum tells you how quiet the machine can be, not how loud it is at the speed that delivers the certified CADR — and on a machine you size to run below maximum, that second number is the one you want. LEVOIT and Coway both publish a range — how loud a purifier actually is next to a bed.
The pre-filter cannot be rinsed. There is a Fine Mesh Pre-Filter, and the manual tells you to clean it with a vacuum or a soft brush and states plainly that it cannot be washed. In a house with a shedding animal that is a meaningful step below the machines with a genuinely washable mesh, though it is a step above the LEVOIT Core range, which documents no pre-filter maintenance at all.
Winix publishes no product page for the model it sells. winixamerica.com has a page for the AT40 and none for the AT41. Everything above that is sourced to Winix comes from the AT40 page or from the manual whose specification table covers both model numbers. That is a thin paper trail for a machine this widely recommended, and it is the reason the contradiction on this page went unnoticed for as long as it did.
AT40 or AT41?
Buy whichever is cheaper on the day, and check what is in the box. The certified figures are identical, the manual is one document, and the part numbers differ by a single digit (1022-0238-01 against 1022-0238-00). The only difference we could find that affects what you pay is the bundle: the AT40 listing we checked includes two filter sets and the AT41 listing does not.
What you should not do is read a review of one and buy the other on the assumption that a different model number means a different certification. On this brand that assumption is wrong often enough to matter — the 5500-2 and its successor are the cautionary example.
Who should buy it
Buy it if you want the most certified air available at this price, your room is up to about 397 square feet, and you are comfortable either leaving a low-measured plasma stage on or pressing the button that turns it off.
Buy something else if anyone in the house is asthmatic and you want a machine whose ion status no source disputes — that is the Honeywell HPA4300 or any LEVOIT Core — or if running cost over several years is the deciding number, which is also the HPA4300.
Buy something bigger if your floor is open plan. At 397 square feet of real two-thirds-rule coverage this is a large-room machine, not a whole-floor one — size it for your own room.
Quick picks
The unit reviewed, and the three machines a reader of this page is most likely to want instead.
| # | Product | Best for | Certified CADR | Price |
|---|---|---|---|---|
| 1 |  The unit reviewed Winix AT41 265 certified CFM across 410 certified sq ft, 0.00 ppb measured, 272 kWh. | Pet allergies, whole living room | 265CFM smoke AHAM VERIFIDE | |
| 2 |  If the ion question has to be closed Honeywell InSight HPA4300 229 certified CFM, recorded HEPA, and no source disputes the zero. | True HEPA on the lowest power draw | 229CFM smoke AHAM VERIFIDE | |
| 3 |  If the room is bigger LEVOIT Core 600S 391 certified CFM across 606 sq ft, fan and filter on every source. | Large open-plan rooms | 391CFM smoke ENERGY STAR verified | |
| 4 |  If you want a washable pre-filter Coway Airmega 400 376 certified CFM, 0.00 ppb, and the only fully published filter bill. | Large rooms, verified Coway | 376CFM smoke ENERGY STAR verified |
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The alternatives, briefly
Winix AT41
Winix · model AT41
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The highest certified smoke CADR of any mid-price unit here, the biggest certified room, and a measured zero on ozone. The register says fan-and-filter; Winix's own manual documents a PlasmaWave button, and this site reports both.
265 smoke / 259 dust / 244 pollen CFM · 261 PM2.5
- Certified room size
- 410 sq ft
- Advertised coverage
- 1,968 sq ft at 1 air change per hour
- Energy / year
- 272 kWh
- Electricity / year
- $50
- Air per watt
- 5.6 CFM/W
- Power draw
- 45 W
- Noise
- 22.04 dB minimum
- Measured ozone
- 0 ppb
- Filter class
- HEPA-Type
- AHAM rule, 380 sq ft
- Clears it (254 needed)
Ionizer status unclear
Unresolved, and reported rather than decided. Both registers say there is no plasma stage: AHAM classifies the model 'Fan with Filter', ENERGY STAR records the sibling AT40 as 'Fan and Filter' and measures 0.00 ppb of ozone on it. Winix's own documentation says otherwise — the AT40/AT41 user manual documents a PlasmaWave button that 'enables or disables PlasmaWave technology', lists PlasmaWave as the fourth of four stages, and Winix's AT40 page publishes an 8-hour ozone figure of 0.12 ppbv. Whatever is fitted, Winix documents it as switchable.
265 certified smoke CADR across 410 certified square feet, filter recorded HEPA + Carbon by AHAM, 0.00 ppb measured on the sibling AT40, and a whole annual bill of about $110 that can actually be computed.
The honest con: Winix documents a switchable PlasmaWave stage that neither register records; the published noise figure is a minimum only; the pre-filter cannot be washed; and Winix publishes no product page for this model number at all.
Honeywell InSight HPA4300
Honeywell · model HPA4300B
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The efficiency winner among true-HEPA units at living-room size: 229 certified smoke CADR on 31 watts, zero measured ozone, and a filter the register classifies as HEPA rather than HEPA-Type.
229 smoke / 238 dust / 245 pollen CFM · 233 PM2.5
- Certified room size
- 354 sq ft
- Energy / year
- 185 kWh
- Electricity / year
- $34
- Air per watt
- 7.4 CFM/W
- Power draw
- 31 W
- Noise
- Not published
- Measured ozone
- 0 ppb
- Filter class
- HEPA
- AHAM rule, 300 sq ft
- Clears it (200 needed)
No ionizer — filtration only
Both registers classify this unit as fan-and-filter only.
229 certified CFM across 354 certified square feet at 7.4 CFM per watt — $34 a year — listed in both registers, filter recorded HEPA, and 0.00 ppb measured with no source anywhere disputing it. Our full review.
The honest con: less air and a smaller certified room than the AT41, no documented pre-filter maintenance, and Honeywell publishes no noise figure, no filter price and no interval — so its annual bill stops at electricity.
LEVOIT Core 600S
LEVOIT · model Core 600S (LAP-C601S-WUS)
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391 certified smoke CADR is real large-room capability, and it is honest about needing 387 kWh a year to deliver it — the highest electricity bill of any LEVOIT we cover.
391 smoke / 398 dust / 436 pollen CFM · 394 PM2.5
- Certified room size
- 606 sq ft
- Advertised coverage
- 2,909 sq ft at 1 air change per hour
- Energy / year
- 387 kWh
- Electricity / year
- $71
- Air per watt
- 6 CFM/W
- Power draw
- 49 W
- Noise
- 26-55 dB
- Measured ozone
- 0 ppb
- Filter class
- HEPA-Type
- AHAM rule, 500 sq ft
- Clears it (334 needed)
No ionizer — filtration only
ENERGY STAR classifies this unit 'Fan and Filter', 0.00 ppb measured ozone.
391 certified CFM across 606 certified square feet with 0.00 ppb measured and 26-55 dB published. Our full review.
The honest con: $71 a year against the AT41’s $50, no washable pre-filter documented, the filter recorded HEPA-Type, and a second ENERGY STAR model code for the same machine that measures 2.00 ppb rather than zero.
Coway Airmega 400
Coway · model Airmega 400 (AP-2015F)
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The Coway that is actually in a certification register: 376 certified smoke CADR, 583 square feet, zero measured ozone. If you want a Coway, this is the one with third-party numbers.
376 smoke / 384 dust / 409 pollen CFM · 380 PM2.5
- Certified room size
- 583 sq ft
- Advertised coverage
- 3,120 sq ft in 60 minutes
- Energy / year
- 366 kWh
- Electricity / year
- $67
- Air per watt
- 6.1 CFM/W
- Power draw
- 66 W
- Noise
- 22-52 dB(A)
- Measured ozone
- 0 ppb
- Filter class
- Composite Filter
- AHAM rule, 500 sq ft
- Clears it (334 needed)
No ionizer — filtration only
ENERGY STAR classifies this unit 'Fan and Filter', 0.00 ppb measured ozone.
376 certified CFM across 583 certified square feet, 0.00 ppb measured, no ion stage on any source, a washable pre-filter on each face, and the most complete filter documentation on this site. Our full review.
The honest con: it is a considerably bigger and dearer machine, it uses 366 kWh a year against the AT41’s 272, and the register declines to classify its filter as HEPA or HEPA-Type at all, recording only “Composite Filter”.
Common questions
Does the Winix AT41 have an ionizer?
Is the Winix AT41 worth it?
What is the difference between the AT40 and the AT41?
Does the AT41 have a washable pre-filter?
What does the AT41 cost to run for a year?
Sources
- AHAM VERIFIDE directory of certified room air cleaners
- ENERGY STAR certified room air cleaners database
- Winix — AT40 product specification and Filter Z listing
- Winix — AT40 / AT41 user manual
- EPA — Guide to Air Cleaners in the Home
Figures were read on the dates shown against each source. If one has changed, or if we have got something wrong, tell us and we will correct the page.
Read next
- Pet allergiesThe Best Air Purifiers for PetsCertified CADR picks for a pet household, with annual running cost computed and every ionizer disclosed.
- Pet allergiesWinix 5500-2 vs LEVOIT: the comparison the spec sheets settleAHAM-certified Winix against ENERGY STAR-certified LEVOIT — and the Winix that beats them both.
- Pet allergiesLEVOIT Core 400S ReviewCertified at 231 CFM and 358 sq ft with zero measured ozone, a published noise range and a published filter price — against a 1,718 sq ft coverage claim.
- Pet allergiesAir purifiers for asthma in a pet householdWhy ionizer status outranks CADR when someone is asthmatic, with measured ozone figures for every unit.