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FilterScored

Data report · 2026

The true cost of clean air and water

We score every air purifier and water filter on the running cost manufacturers hide and the certifications they blur. This report aggregates what those numbers look like across our catalog of 25 air purifiers and 25 water filters. Every figure is computed from the same data behind the scorecards, so it updates as the catalog grows.

Key findings

  • 44% of scored water filters (11 of 25) market lead or PFAS reduction they hold no accredited certification for.
  • The priciest air purifier to run costs about 14x more per year in filters than the cheapest ($349.98/yr vs $24.99/yr).
  • Only 56% of air purifiers publish an AHAM-verified CADR; the other 11 ask you to trust a marketing number.
  • Cost per gallon swings enormously by format: from about $0.001/gal for whole-house carbon to $1.17/gal for a small-cartridge pitcher - the low sticker price hides the priciest water you can filter.

Air purifiers

$84
Median annual filter cost across scored air purifiers
56%
Publish an AHAM-verified CADR (the rest ask you to trust a marketing number)
10
of 25 use an ionizer or ozone-generating stage
11
overstate their room-size coverage versus their own CADR

The cheapest air purifier to run in our set is the GermGuardian AC4825E at about $24.99/year in filters. The priciest is the Molekule Air Pro at about $349.98/year - roughly 14x more, for filters alone.

Over five years, total cost of ownership ranges from about $224.94 (GermGuardian AC4825E) to about $2749.89 (Molekule Air Pro). Sticker price is a poor guide to either.

Water filters

$0.167
Median cost per gallon across scored water filters
68%
hold at least one accredited NSF/WQA/IAPMO certification
8
of 25 make contaminant claims with zero accredited certification ('tested to', not 'certified to')
11
market lead or PFAS removal they are not certified for

Cost per gallon spans a wide range: from about $0.001/gal (Aquasana Rhino EQ-1000 Whole House) to about $1.167/gal (ZeroWater 5-Stage Pitcher (7-Cup)). Pitchers with small cartridges are usually the most expensive water you can filter, despite the low sticker price.

The headline finding is the one our whole methodology is built on: a meaningful share of popular water filters make lead or PFAS claims with no accredited certification behind them. A claim is not a certification. See our guide on the difference, the full claimed-vs-certified breakdown for every filter, or check whether a specific brand is certified in Is your water filter NSF certified?.

Furnace filters

Furnace filters have their own version of "tested to vs certified to": MERV is the one standardized rating (ANSI/ASHRAE 52.2), while the big MPR (3M) and FPR (Home Depot) numbers on the box are proprietary scales the seller controls - and the same FPR number can map to a different MERV by filter depth. We score the true MERV and mark a brand down for hiding it. See the full MERV-honesty breakdown for every furnace filter, or the guide on MERV vs MPR vs FPR.

Method

Figures are computed across every product on FilterScored at the time of writing. Annual filter cost is replacement-filter price times replacements per year; cost per gallon is cartridge price divided by rated gallons. Certification counts reflect only certifications verifiable on an official NSF, WQA, or IAPMO database. Products with no public replacement-filter price are excluded from cost figures and labeled on their scorecards. See the full methodology.

Cite this report

Journalists and researchers are welcome to cite these figures with attribution to FilterScored and a link to this page. The underlying data is available under a CC BY 4.0 license.

FilterScored. "The True Cost of Clean Air and Water (2026 Data Report)." https://www.filterscored.com/reports/

Questions or a figure you want broken out for a story? editor@filterscored.com.