Air Purifiers / Alen BreatheSmart 75i (V2) vs Medify Air MA-40 (V4.0)
Alen BreatheSmart 75i (V2) vs Medify Air MA-40 (V4.0)
Alen BreatheSmart 75i (V2)
Best sensors and a lifetime warranty — as long as you never cancel the filter subscription.
Wins overall by 2.1 points
Quick Verdict
The Alen BreatheSmart 75i (V2) takes this by a clear 2.1 points. Best sensors and a lifetime warranty — as long as you never cancel the filter subscription. The Medify Air MA-40 (V4.0) only makes sense if it wins on a category you care about more than the total.
The Alen BreatheSmart 75i (V2) and Medify Air MA-40 (V4.0) are both closely matched air Purifier models, and the Medify Air MA-40 (V4.0) is $549 cheaper than the Alen BreatheSmart 75i (V2) ($249.99 vs $799). On Sensor Quality, the Alen BreatheSmart 75i (V2) leads (8.5 vs 1.0/10) — whether there is a real laser particle sensor resolving PM1/PM2.5/PM10 with numeric output, a vaguer 'air quality' index, an inference from a cheap VOC element, or no sensor and therefore no auto mode at all. On Quietness, the Alen BreatheSmart 75i (V2) leads (8.0 vs 4.0/10) — measured decibels at the lowest setting you would run overnight AND at the top speed you need in a smoke event — a purifier is only useful at a speed you can tolerate. Not publishing a figure at either end costs points. On Controls & Independence, the Alen BreatheSmart 75i (V2) leads (8.0 vs 6.0/10) — whether every mode works from the machine itself with no account or cloud, how good the auto mode is, filter-change access, and whether losing a remote or a login costs you function. Overall, the Alen BreatheSmart 75i (V2) scores 6.9/10 across our 8 scoring categories versus 4.8/10 for the Medify Air MA-40 (V4.0). Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Alen BreatheSmart 75i (V2) | Medify Air MA-40 (V4.0) |
|---|---|---|
| Price | $799.00 | $249.99 |
| Release Year | 2024 | 2019 |
| AHAM Verifide CADR (Smoke / Dust / Pollen) (CFM) | Alen publishes a CADR of 375 on the 75i spec block and 350 in its own product description on the same page — Sources conflict: 375 (Alen spec table) vs 350 (Alen product description). Not AHAM Verifide: Alen does not appear in the AHAM Verifide directory in August 2026, so neither figure is independently confirmed, and neither is broken out by smoke, dust and pollen. | Medify publishes smoke 239 / dust 231 / pollen 240 / PM2.5 235 CFM itself, footnoted "Smoke CADR when operating at highest fan speed". Medify's own listings display an "AHAM Verified" badge on every product — but a query of the AHAM Verifide directory in August 2026 returns the brand "Medify Air" in the brand index with ZERO currently certified models. Treat these as manufacturer figures until a directory entry appears. |
| AHAM Verifide Room Size (4.8 ACH) (ft²) | Not listed in the AHAM Verifide directory (August 2026). At Alen's own 375 CADR, the equivalent 4.8-ACH room would be about 580 ft², not the 2,800 ft² on the box. | No current AHAM Verifide listing (August 2026), despite the "AHAM Verified" badge on medifyair.com. Medify's own 5-ACH figure is 358.5 ft² and its 4-ACH figure is 448 ft². |
| Coverage Claim & Its Air-Change Basis | "Covers up to 2,800 sq ft every hour or 1,400 sq ft every 30 minutes" — that is 1 air change per hour and 2 air changes per hour respectively. Alen never quotes a 4.8-ACH figure. The gap between the 2,800 ft² headline and the roughly 580 ft² its own CADR implies at 4.8 ACH is the largest in this file. | Medify's own table: 1,793 ft² at 1 ACH, 896 ft² at 2 ACH, 448 ft² at 4 ACH, 358.5 ft² at 5 ACH. The headline everywhere — site, packaging, Amazon title — is the 2-ACH number, "896 sq ft in 30 minutes". Two air changes an hour is roughly half what smoke or allergen control needs. |
| Filter Grade (True HEPA / HEPA-Type / H13) | True HEPA H13 rated at 99.9% down to 0.1 microns (Alen's wording). Four interchangeable filters: Essential/Pure, Fresh, Odor and Heavy Odor, the latter three adding progressively more carbon. | Medify markets "True HEPA H13" (and H14 on some SKUs). The footnote on every page reads "Tested by Intertek Lab for HEPA filter material" — the H13 grade is a claim about the media, not a whole-unit sealed-system rating. Three stages: pre-filter, H13 media, pelletised activated carbon. |
| Pre-Filter (Washable?) | Integrated into each filter cartridge — not separately washable | Integrated into the single replaceable cylinder — not separately washable |
| Filter Cost per Year | $79.20–$99.00/yr with the Essential (Pure) filter at $99 on Alen's stated 12–15 month interval; $166.80–$238.29/yr with the Ultimate (Odor) filter at $139 on its 7–10 month interval. And note the warranty coupling below: the filter subscription is not optional if you want the lifetime guarantee. | $119.98–$179.97/yr, and Medify's own site cannot agree with itself: the MA-40 filter page sets the subscription cadence at 120 days, the purifier page sets it at 180 days, and the body copy says the filter lasts "up to 3,000 hours or 4-5 months". At $59.99 a filter that is two to three filters a year. The subscription discounts the first filter 40% ($35.99) and later ones 10% ($53.99). |
| Ioniser / UV / PCO & CARB Classification | Yes, and it is switchable — Alen publishes the numbers at both settings: "0 PPM when disengaged, less than 0.001 PPM with ionizer engaged". CARB certifies the BreatheSmart 75i_V2 as an ELECTRONIC device (EO G-24-038, notified 2024-02-26), and the 45i V2 likewise (G-25-209). Ozone-capable by construction, tested at or below 0.050 ppm, and defeatable in software. | The standard MA-40 has an optional ioniser (Medify's own controls list reads "Ionizer (Optional)") and Medify describes the unit as ozone-free. CARB history is instructive: the original MA-40 (EO G-21-461, 2021) and the MA-40UV are certified as ELECTRONIC devices, while MA-40-V3.0 (G-23-267) and the current MA-40-V4.0 (G-25-237, 2025-09-10) are certified as MECHANICAL. Buy the current V4.0 HEPA SKU, not a UV or ioniser variant. |
| Noise, Lowest to Highest Setting (dB) | 25 dBA lowest to 51 dBA highest (Alen published) | Medify publishes only the sleep-mode figure, "as low as 40.5 dBA". No figure is published for the top speed. 40.5 dBA is by far the loudest quiet-setting in this file — the Levoit Core 300S-P is 22 dB and the Blueair 23 dB. |
| Air Quality Sensor | The most complete sensing package here: PM2.5, TVOC, eCO2, temperature and relative humidity, driving five colour rings and an auto mode. Note eCO2 on this class of device is normally inferred from the VOC sensor rather than measured with an NDIR CO2 cell, and Alen does not state which it is. | None. The MA-40's own controls list is "Preset Timers, 3 Fan Speeds, Sleep Mode, Filter Indicator, Touch Controls, Child Lock, Ionizer (Optional)" — there is no particle sensor and therefore no auto mode at any price. |
| Smart Features & Offline Operation | Wi-Fi and the Alen Air app need an account. Fan speed and auto mode work from the panel offline — but the "Forever Guarantee" requires an active filter subscription, which is a commercial dependency rather than a technical one. | None. No Wi-Fi, no app, no account. Fully offline. |
| Power Draw & Annual Energy | 1.36W to 55W across the speed range (Alen published) | 68W (Medify published); Integrated Energy Factor 3.6 |
| Warranty Terms & Conditions | "Forever Guarantee | with Product Registration & Active Air Filter Subscription" — Alen's lifetime warranty is conditional on you continuing to buy filters on subscription. Cancel the subscription and the guarantee lapses. warrantyMonths is recorded as 0 because the term is conditional and not expressible in months. | Limited Lifetime Warranty with no filter-subscription requirement — unusually generous, and the reason warrantyMonths is recorded as 0 rather than a month count. Plus a 30-day home trial. |
| Warranty | 0 months | 0 months |
| Colors | White, Oak, Weathered Gray, Brushed Stainless, Graphite | White, Black |
Category Scores
Coverage-Claim Honesty
The Medify Air MA-40 (V4.0) leads clearly here, 3.5 against 3.0 — a 0.5-point margin on the trap dimension for this category. Almost every brand derives its headline square footage from ONE air change per hour, which does close to nothing for smoke, pollen or wildfire particulate — the useful standard is 4.8 air changes an hour, and it is typically a fifth of the number on the box. A high score means the manufacturer publishes the 4.8-ACH figure prominently and it survives comparison with the AHAM Verifide room size; a low score means a big number with no stated air-change basis, or no CADR at all to derive one from.. If that is what you are buying for, the Alen BreatheSmart 75i (V2) does not close the gap elsewhere.
Verified Clean-Air Delivery
The Alen BreatheSmart 75i (V2) leads clearly here, 6.5 against 6.0 — a 0.5-point margin on how much air the unit actually cleans per minute, weighted heavily toward AHAM Verifide smoke CADR over manufacturer-published figures. Self-reported CADR scores below Verifide CADR, and 'no CADR published at all' scores below both. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Filtration Quality
The Alen BreatheSmart 75i (V2) leads clearly here, 8.5 against 7.5 — a 1.0-point margin on what the media is really rated at — sealed H13, True HEPA, HEPA-Type, EPA 12 or charged fabric — whether the whole machine is sealed so air cannot bypass the filter, and how much genuine activated carbon there is for odours and VOCs. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Running Cost
The Alen BreatheSmart 75i (V2) leads clearly here, 5.0 against 3.5 — a 1.5-point margin on filters, pre-filters, cartridges and subscriptions over three years, against the purchase price. Several units here cost more to feed than to buy; a high score means cheap, long-lived, non-proprietary consumables. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Quietness
The Alen BreatheSmart 75i (V2) leads clearly here, 8.0 against 4.0 — a 4.0-point margin on measured decibels at the lowest setting you would run overnight AND at the top speed you need in a smoke event — a purifier is only useful at a speed you can tolerate. Not publishing a figure at either end costs points. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Sensor Quality
The Alen BreatheSmart 75i (V2) leads clearly here, 8.5 against 1.0 — a 7.5-point margin on whether there is a real laser particle sensor resolving PM1/PM2.5/PM10 with numeric output, a vaguer 'air quality' index, an inference from a cheap VOC element, or no sensor and therefore no auto mode at all. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Freedom From Ozone & Air Chemistry
The Alen BreatheSmart 75i (V2) leads clearly here, 7.5 against 7.0 — a 0.5-point margin on whether the unit adds an ioniser, plasma, UV or photocatalytic stage to the airstream, whether that stage can be switched off, and how CARB classifies the device — 'Mechanical' means filtration only, 'Electronic' means capable of generating ozone and certified only as being at or below 0.050 ppm. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Controls & Independence
The Alen BreatheSmart 75i (V2) leads clearly here, 8.0 against 6.0 — a 2.0-point margin on whether every mode works from the machine itself with no account or cloud, how good the auto mode is, filter-change access, and whether losing a remote or a login costs you function. If that is what you are buying for, the Medify Air MA-40 (V4.0) does not close the gap elsewhere.
Best For
Choose the Alen BreatheSmart 75i (V2) if…
- • Sensor Quality matters most to you — the Alen BreatheSmart 75i (V2) scores 8.5/10 here (whether there is a real laser particle sensor resolving PM1/PM2.5/PM10 with numeric output, a vaguer 'air quality' index, an inference from a cheap VOC element, or no sensor and therefore no auto mode at all).
- • Quietness matters most to you — the Alen BreatheSmart 75i (V2) scores 8.0/10 here (measured decibels at the lowest setting you would run overnight AND at the top speed you need in a smoke event — a purifier is only useful at a speed you can tolerate. Not publishing a figure at either end costs points).
- • Controls & Independence matters most to you — the Alen BreatheSmart 75i (V2) scores 8.0/10 here (whether every mode works from the machine itself with no account or cloud, how good the auto mode is, filter-change access, and whether losing a remote or a login costs you function).
- • Running Cost matters most to you — the Alen BreatheSmart 75i (V2) scores 5.0/10 here (filters, pre-filters, cartridges and subscriptions over three years, against the purchase price. Several units here cost more to feed than to buy; a high score means cheap, long-lived, non-proprietary consumables).
- • Filtration Quality matters most to you — the Alen BreatheSmart 75i (V2) scores 8.5/10 here (what the media is really rated at — sealed H13, True HEPA, HEPA-Type, EPA 12 or charged fabric — whether the whole machine is sealed so air cannot bypass the filter, and how much genuine activated carbon there is for odours and VOCs).
Choose the Medify Air MA-40 (V4.0) if…
- • You want to spend less — it's $549 cheaper.
Pros & Cons
Alen BreatheSmart 75i (V2)
Pros
- +Publishes actual ozone figures at both ioniser settings — 0 ppm off, under 0.001 ppm on — which almost nobody does
- +PM2.5, TVOC, eCO2, temperature and humidity sensing is the broadest package here
- +25–51 dBA across the whole range from a genuinely large-room machine
- +Four filter chemistries in one body, so you can retune it for odour or wildfire smoke
- +Interchangeable panels make it the only unit here designed to be seen
Cons
- −The "Forever Guarantee" is conditional on registration AND an active filter subscription — stop buying filters and the lifetime warranty stops
- −"Up to 2,800 sq ft" is a 1-ACH figure; Alen's own CADR implies roughly 580 ft² at the 4.8 ACH that matters
- −Alen's own page states two different CADRs, 375 and 350, in two places
- −Not in the AHAM Verifide directory, so nothing about the CADR is independently confirmed
- −CARB lists the 75i_V2 as an Electronic (ozone-capable) device, and the Odor filter pushes running costs past $165/yr
Medify Air MA-40 (V4.0)
Pros
- +239 CFM smoke CADR is real firepower for $250 and beats every unit here below $340
- +Limited lifetime warranty with no registration-plus-subscription strings, unlike Alen's Forever Guarantee
- +Pelletised carbon rather than carbon-coated mesh gives it more genuine odour capacity than most
- +Publishes its coverage at four different ACH values, so the honest number is at least findable
- +The current V4.0 is CARB-certified Mechanical — no ozone pathway on the standard HEPA SKU
Cons
- −Every Medify listing carries an "AHAM Verified" badge, yet the AHAM Verifide directory shows zero certified Medify Air models in August 2026
- −The famous "896 sq ft" is a 2-ACH figure; at the 4–5 ACH that actually controls smoke it is 358–448 ft²
- −H13 is footnoted as "tested by Intertek for HEPA filter material" — media grade, not a sealed-unit rating
- −Sleep mode is 40.5 dBA. That is audible-conversation territory and the top speed is not published at all
- −$59.99 filters on a 120–180 day cadence — Medify's own pages disagree — means $120–180 a year, near the price of a whole Levoit
- −No sensor of any kind, so no auto mode: you are the air-quality sensor
Shop by Need
FAQs
Is the Alen BreatheSmart 75i (V2) or Medify Air MA-40 (V4.0) better overall?+
Based on our 8-category scoring, the Alen BreatheSmart 75i (V2) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Sensor Quality, the Alen BreatheSmart 75i (V2) or the Medify Air MA-40 (V4.0)?+
The Alen BreatheSmart 75i (V2) scores higher on Sensor Quality (8.5/10 vs 1.0/10) — whether there is a real laser particle sensor resolving PM1/PM2.5/PM10 with numeric output, a vaguer 'air quality' index, an inference from a cheap VOC element, or no sensor and therefore no auto mode at all.
Which is better for Quietness, the Alen BreatheSmart 75i (V2) or the Medify Air MA-40 (V4.0)?+
The Alen BreatheSmart 75i (V2) scores higher on Quietness (8.0/10 vs 4.0/10) — measured decibels at the lowest setting you would run overnight AND at the top speed you need in a smoke event — a purifier is only useful at a speed you can tolerate. Not publishing a figure at either end costs points.
Which is better for Controls & Independence, the Alen BreatheSmart 75i (V2) or the Medify Air MA-40 (V4.0)?+
The Alen BreatheSmart 75i (V2) scores higher on Controls & Independence (8.0/10 vs 6.0/10) — whether every mode works from the machine itself with no account or cloud, how good the auto mode is, filter-change access, and whether losing a remote or a login costs you function.
Which is better for Running Cost, the Alen BreatheSmart 75i (V2) or the Medify Air MA-40 (V4.0)?+
The Alen BreatheSmart 75i (V2) scores higher on Running Cost (5.0/10 vs 3.5/10) — filters, pre-filters, cartridges and subscriptions over three years, against the purchase price. Several units here cost more to feed than to buy; a high score means cheap, long-lived, non-proprietary consumables.
Is the Alen BreatheSmart 75i (V2) worth the price difference over the Medify Air MA-40 (V4.0)?+
The Medify Air MA-40 (V4.0) is the cheaper option at $249.99 versus $799. Whether the pricier model is "worth it" depends on how much you value its lead in Sensor Quality.
Which is better suited to my use case?+
The Alen BreatheSmart 75i (V2) is the better fit if you mainly care about bedroom-quiet. The Medify Air MA-40 (V4.0) is the better fit for large-room or wildfire-smoke.
What's the warranty on the Alen BreatheSmart 75i (V2) vs the Medify Air MA-40 (V4.0)?+
The Alen BreatheSmart 75i (V2) ships with a 0-month warranty; the Medify Air MA-40 (V4.0) ships with a 0-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Coway Airmega AP-1512HH Mighty — $239.99
Premium Option
Molekule Air Pro with PECO-HEPA Tri-Power filter (SQ2PH-US) — $1014.99
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.