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.
Bottom line
In our scoring the Medify MA-40 earns 5.9/10, a weak result, and it stands out on certification (10.0/10). On the data, its 240 cfm CADR is AHAM-verified. Filters run about $120 a year (~$850 over five years with the device), on the expensive end to run. Its weakest area in our scoring is total cost of ownership (2.5/10).
Where to buy
No buy link on this one: it scored Limited under our rubric, and we only link products we would shortlist ourselves.
Total cost of ownership
Checked 42 days ago- Annual filters
- $120/yr
- Device
- $250
- 5-year total
- $850
Certifications
- Energy Star Room Air Cleanersefficiency
- CARB ozone complianceozone
- AHAM Verifidesmoke, dust, pollen
Filters only protect you on their swap schedule. Get an email reminder when this one is due - one note around swap time, nothing else.
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 240 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
- 240 cfm (AHAM-verified)
- Real coverage at 4.8 ACH
- ~372 sq ft
- Manufacturer room claim
- 370 sq ft
- 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
- - Total Cost of Ownership: 2.5/10
Who it is for
- · Large living rooms and open-plan spaces
Who should skip it
- · 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
7.0/10 · 30%AHAM CADR, true sealed HEPA, air changes per hour, honest room-size match.
- +3AHAM Verifide CADR published A240 cfm (AHAM Verifide) - CADR is third-party verified by AHAM, not a manufacturer claim.
- +2Hits ~5 air changes/hour at rated room B4.9 ACH at 370 sq ft - Delivers at least 4.8 air changes per hour at its rated room size.
- +2Honest room-size claim Brated 370 sq ft, CADR supports 372 - Claimed room size is within what the unit's own CADR can clean.
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
- Is the Medify MA-40's CADR AHAM-verified, and does it emit ozone?
- Its 240 cfm Clean Air Delivery Rate is AHAM-verified - independently tested, not a box claim. It has a defeatable ionizer, CARB-certified for low ozone.
- 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.
Compared head-to-head
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 2026-06-06. Scored under air-v1.0. Prices were last checked 42 days ago; the freshness chip above the cost panel shows the current state. See the methodology for how each rule fires.