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AirDoctor AD5500 3-Stage UltraHEPA Air Purifier vs PuroAir 400 HEPA Air Purifier

These are side-by-side facts taken from each product guide: published specifications, strengths and caveats as their sources state them. This page is not a test, a ranking or a verdict about which model is better.

AirDoctor AD5500 3-Stage UltraHEPA Air Purifier

Large open rooms around 1,000 sq ft with space for a tall floor unit

AirDoctor's AD5500 runs two sets of pre-filters, carbon filters and UltraHEPA filters. AirDoctor gives 1,043 square feet at four air changes per hour and a 556 CFM smoke CADR. It stands 28.75 inches tall, needs paired filter changes, and carries a one-year warranty.

Published specifications

  • AirDoctor: 1,043 sq ft at 4 air changes per hour
  • AirDoctor: smoke CADR 556 CFM (standard not stated)
  • AirDoctor: 16 x 16 x 28.75 in, 33 lb
  • AirDoctor: two pre, two carbon, two UltraHEPA filters
  • Listing: carbon every 6 months, UltraHEPA every 12
  • AirDoctor: one-year limited warranty, service fee applies

Strengths

  • High airflow for large open rooms per the maker's figures
  • Two permanent pre-filters listed in the box contents
  • Six fan speeds per the listing

Caveats

  • Every filter change is a pair of filters
  • Listing coverage figures differ from AirDoctor's
  • One-year warranty; no manual found online

Check this model on Amazon

Read the full AirDoctor AD5500 3-Stage UltraHEPA Air Purifier guide

PuroAir 400 HEPA Air Purifier

Buyers wanting auto mode and a child lock who accept unpublished CADR

The PuroAir 400 uses one composite filter with an air-quality sensor, auto mode, timer and child lock. PuroAir claims 2,000 square feet an hour but publishes no CADR, and its manual gives both 8-inch and 3-foot clearances. Two-year warranty with registration.

Published specifications

  • PuroAir: up to 2,000 sq ft in an hour; no CADR published
  • PuroAir: 14.4 L x 8.1 W x 21.5 H in, 14.7 lb, 80 W
  • Manual: auto mode, fan speeds, 2/4/6/8 h timer, child lock
  • Manual: >8 in from obstacles; 3 ft from appliances
  • Manual: filter not washable; reset hold 10 s
  • Manual: two-year warranty with registration

Strengths

  • Auto mode with a sensor that calibrates on power-up
  • Timer and child lock
  • Manual describes a sensor test at 12 inches

Caveats

  • No CADR or verified room size published
  • Manual gives conflicting clearance distances
  • Humidity can push auto mode to higher speeds

Check this model on Amazon

Read the full PuroAir 400 HEPA Air Purifier guide

How to choose between them

Choose the AirDoctor AD5500 3-Stage UltraHEPA Air Purifier if your situation matches: Large open rooms around 1,000 sq ft with space for a tall floor unit. Its main caveat: Every filter change is a pair of filters.

Choose the PuroAir 400 HEPA Air Purifier if your situation matches: Buyers wanting auto mode and a child lock who accept unpublished CADR. Its main caveat: No CADR or verified room size published.

Both entries repeat what each guide records. Confirm the model, included parts and availability on the current listing before ordering.

Primary sources

  1. AirDoctor product page for the AirDoctor 5500 Source for AirDoctor AD5500 3-Stage UltraHEPA Air Purifier
  2. AirDoctor one-year limited warranty page Source for AirDoctor AD5500 3-Stage UltraHEPA Air Purifier
  3. PuroAir product page for the PuroAir 400 Source for PuroAir 400 HEPA Air Purifier
  4. PuroAir 400 user manual Source for PuroAir 400 HEPA Air Purifier
  5. PuroAir user manuals index Source for PuroAir 400 HEPA Air Purifier

Primary sources checked .