Right Size Air product guide
AirDoctor AD3500 3-Stage UltraHEPA Air Purifier
Rooms up to about 630 sq ft by AirDoctor's four-changes-per-hour figure
AirDoctor's AD3500 pairs a carbon filter with potassium permanganate and an UltraHEPA filter behind a pre-filter. AirDoctor gives 630 square feet at four air changes per hour and a 340 CFM smoke CADR. Carbon is changed every six months, UltraHEPA yearly, under a one-year warranty.
Listing checked . Confirm the model, included parts and availability before ordering.
Published specifications
- AirDoctor: 630 sq ft at 4 air changes per hour
- AirDoctor: smoke CADR 340 CFM (standard not stated)
- AirDoctor: 15.75 W x 8.75 D x 23 H in, 18 lb
- Listing: carbon every 6 months, UltraHEPA every 12
- Listing: PM2.5 auto mode, 4 fan speeds, timer
- AirDoctor: one-year limited warranty, service fee applies
Fit and limits
Strengths
- Listing describes a carbon stage with potassium permanganate
- Clear four-changes-per-hour room figure from the maker
- Filters shared with the older AD3000
Caveats
- Carbon filter needs replacing every six months
- One-year warranty with a shipping and processing fee
- No manual found online for clearance or cleaning
What the AD3500 is and what is in the box
The AD3500 is AirDoctor's 3500 model. AirDoctor's page lists three filtration stages, with a pre-filter that comes attached to the carbon filter and an UltraHEPA filter behind it. The Amazon listing describes the carbon stage as activated carbon with potassium permanganate. AirDoctor's page offers Classic and Smart versions.
The Amazon listing says auto mode uses PM2.5 sensors with a colour-coded Halo light, with four fan speeds and a timer. AirDoctor's filter collection lists replacement pre-filters, carbon filters, UltraHEPA filters and combo packs as compatible with both the AD3500 and the older AD3000.
Coverage: 630 square feet at four changes an hour
AirDoctor's technical specifications give room coverage of up to 630 square feet at four air changes per hour, and a smoke CADR of 340 cubic feet per minute. The 2,520 square foot figure on Amazon is for one air change per hour, the same airflow spread across four times the floor area.
Neither AirDoctor page we read names the test standard behind the CADR or mentions AHAM verification, and only a smoke figure is given. Use the 630 square foot number when sizing a room, and note that neither page states a ceiling height for that figure.
Size and weight figures do not agree
AirDoctor lists the unit at 15.75 inches wide, 8.75 inches deep and 23 inches tall, weighing 18 pounds. The Amazon listing gives several different sets of dimensions, including 20 by 20 by 20 inches and 24 by 16 by 8.5 inches, and weights of 23.9 and 24 pounds.
The listing does not explain which figures describe the unit and which the carton. For shelf or floor planning, use AirDoctor's figures and allow extra space around the intake and outlet, since we found no manual stating the clearance AirDoctor recommends.
Filter schedule: carbon twice as often as HEPA
The Amazon listing says to replace the carbon filter every six months and the UltraHEPA filter every 12 months. AirDoctor's own filter subscription ships the first order at six months and then every 12 months, which matches those intervals.
So the running pattern is one carbon change at six months and a carbon and HEPA change at twelve. AirDoctor sells the pre-filter in three-packs; how often it should be cleaned or replaced is in the manual, which we could not find online. The listing says the UltraHEPA filters are made in Japan.
Claims we do not repeat
AirDoctor's page and the Amazon bullets make broad claims about removing bacteria, viruses and toxic gases, compare UltraHEPA with the HEPA standard at 0.003 microns, and describe wellness benefits. We did not review the testing behind these claims, so this guide does not restate them as facts.
What the pages do state plainly is the filter construction, the four-times-per-hour coverage figure, a smoke CADR and the replacement intervals. Neither page we read says whether the unit produces ozone or carries CARB certification, so we make no claim either way.
One-year warranty, with a shipping and processing fee
AirDoctor's warranty page gives a one-year limited warranty from the original purchase date against defects in materials and workmanship, for the original purchaser only. AirDoctor repairs or replaces a defective unit without charge, but the page says a shipping and processing fee will apply.
The warranty excludes accident, misuse, use other than described in the product manual, and damage from failing to maintain and clean the unit as the manual specifies. The product page also advertises a five-year extended warranty that is included only while a filter subscription is active. Amazon purchases are not mentioned; confirm with AirDoctor before counting on more than one year.
Check the current listing
Confirm the model, included parts and availability before ordering.
Primary sources
- AirDoctor product page for the AirDoctor 3500
- AirDoctor 3000-series replacement filters for AD3500 and AD3000
- AirDoctor one-year limited warranty page
Primary sources checked .
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