Air purifier · large-room
Medify MA-40
An affordable large-room H13 True HEPA purifier with an activated carbon layer and an optional ionizer that can be switched off.
Flags
- · Claimed room size exceeds what the unit's AHAM CADR can deliver.
Flags indicate missing certifications or data gaps under our rubric, not a confirmed finding that a product fails to perform.
Total cost of ownership
- Annual filters
- $120/yr
- Device
- $250
- 5-year total
- $850
Certifications
- Energy Star Room Air Cleanersefficiency
- CARB ozone complianceozone
- AHAM Verifidesmoke, dust, pollen
Overview
The Medify MA-40 is a large-room air purifier built around a H13 filter. Its Clean Air Delivery Rate is AHAM-verified at 380 cfm, and it uses a defeatable ionizer (can be switched off). Filters run about $120 per year, on the expensive end to run.
By the numbers
- Clean Air Delivery Rate
- 380 cfm (AHAM-verified)
- Real coverage at 4.8 ACH
- ~589 sq ft
- Manufacturer room claim
- 840 sq ft (a ~2 ACH figure; larger than its CADR supports)
- Filter
- H13
- Ozone / ionizer
- a defeatable ionizer (can be switched off)
- Noise (low)
- 46 dBA, 41 dBA sleep
- Annual filter cost
- $120/yr
- 5-year cost of ownership
- $850 (device + filters)
- Certifications
- Energy Star Room Air Cleaners, CARB ozone compliance, AHAM Verifide
Strengths
- + Certification: 10.0/10
Watch-outs
- - Verified Performance: 3.0/10
- - Total Cost of Ownership: 2.5/10
- - Claimed room size exceeds what the unit's AHAM CADR can deliver.
Who it is for
- · Large living rooms and open-plan spaces
Who should skip it
- · Large rooms - its real coverage is smaller than the box claims
- · Buyers focused on low running cost - filters are pricey
What to know before buying
- · The MA-40 uses a 3-in-1 replacement filter (pre-filter, H13 HEPA, activated carbon; part MA-40-R) that Medify rates for about 4 months or 3,000 hours, a relatively short cadence.
- · Measured noise runs from about 46 dB on the lowest setting to roughly 66 dB at top speed, on the louder end for its class.
- · The unit is AHAM-verified and CARB-certified, and Medify states its ionizer models are tested to produce zero ozone.
How it scored
Verified Performance
3.0/10 · 30%AHAM CADR, true sealed HEPA, air changes per hour, honest room-size match.
- +3AHAM Verifide CADR published A380 cfm (AHAM Verifide) - CADR is third-party verified by AHAM, not a manufacturer claim.
Total Cost of Ownership
2.5/10 · 25%Computed annual filter cost vs the room-size class median. The number nobody surfaces.
- +2.5Annual filter cost vs class median A$119.98/yr (near class median) - Computed annual filter cost scored against the room-size class median.
Certification
10.0/10 · 15%AHAM Verifide, Energy Star, CARB, published lab efficiency.
- +3AHAM Verifide seal AAHAM Verifide - Carries the AHAM Verifide performance seal.
- +2Energy Star certified AEnergy Star - Energy Star certified for energy efficiency.
- +2CARB certified ACARB compliant - Meets California's air-cleaning-device ozone-emission rules.
- +3Published lab-tested efficiency AAHAM-listed CADR - Filtration performance is independently lab-tested and published.
Safety
5.0/10 · 15%Ozone and ionizer behavior. Ozone generators hard-fail.
- +5Ionizer is CARB-certified and defeatable ACARB ionizer, switchable - Ionizer can be turned off and meets CARB ozone limits.
Practical Fit
6.0/10 · 15%Noise, filter-change indicator, energy draw. Smart features are neutral.
- +4Quiet at low speed B46 dBA low - Runs at 50 dBA or quieter on its lowest useful speed.
- +2Filter-change indicator Bindicator present - Tells you when the filter actually needs replacing.
- ·Smart features (neutral) Capp / auto mode - App control and auto mode are neither rewarded nor penalized.
FAQ
- How often does the MA-40 filter need replacing?
- Medify recommends replacing the combined H13 HEPA and carbon filter about every 4 months, or after roughly 3,000 hours, more frequent than many 12-month rivals.
- Is the MA-40 loud?
- At its lowest setting it measures around 46 dB, and at maximum speed it can reach about 66 dB, so the top speeds are noticeably loud.
Related guides
This score is our opinion under our published rubric, not a statement of objective fact or a lab test of this product. We score what third-party certifications prove; absence of a certification means we found no verification, not that a product fails to perform. Last reviewed 2026-06-01. Scored under air-v1.0. Prices and certifications are re-verified on a cadence; see the methodology for how each rule fires.