Current offer comparison — October 25, 2026 snapshot
These are DealsChecked feed observations collected at 12:45 UTC, not completed checkout tests. Cards can refresh separately. The merchant confirms the final price, seller, shipping, tax and return terms.
| Use | Product | Feed price | Feed discount | Offer type | Action |
|---|---|---|---|---|---|
| Bedroom or home office | AIRDOCTOR AD2000 for Small & Medium Rooms and Small Bedrooms. 3 Stage Filtration with Pre-Filter, UltraHEPA, Carbon/VOCShop on Amazon Details | $368.10 | 10% | Automatic discount | Shop on Amazon |
| Living room or large bedroom | AIRDOCTOR Air Purifier for Home, Medium/Large Rooms up to 2520 ft² | AD3500Shop on Amazon Details | $503.10 | 10% | Automatic discount | Shop on Amazon |
| Slightly larger room | AIRDOCTOR AD4000 Air Purifier. Perfect for Large Rooms, Basements Up to 2,776 ft2. Removes Smoke, Dust, Pet Hair, Odors, Pollen. Hospital-Grade UltraHEPA & Premium Carbon FiltrationShop on Amazon Details | $719.10 | 10% | Automatic discount | Shop on Amazon |
| Open floor plan | AIRDOCTOR AD5500 Air Purifier. Cleans Whole Home, Extra Large Rooms Up to 4172 ft2. Removes Smoke, Dust, Pet Hair, Odors, Pollen. Hospital-Grade UltraHEPA & Premium Carbon FiltrationShop on Amazon Details | $899.10 | 10% | Automatic discount | Shop on Amazon |
How to choose an AirDoctor purifier
These are AirDoctor's four purifiers with current offers. We compare them on the coverage and smoke CADR printed on AirDoctor's own product pages, because those pages use one basis: the floor area each model can circulate four times an hour.
Before opening an offer, multiply the room's length by its width. Pick the smallest model whose four-changes-an-hour figure covers that number, and choose a unit sized for a larger area if the ceiling is above 8 feet, as the EPA suggests.
Which model fits your room
AirDoctor's AD2000 page says it circulates the air in 305 square feet four times an hour and lists a smoke CADR of 162 CFM. AirDoctor's AD3500 page says it circulates the air in 630 square feet four times an hour and lists a smoke CADR of 340 CFM. AirDoctor's AD4000 page lists room coverage up to 694 square feet at four air changes an hour and a smoke CADR of 370 CFM. AirDoctor's AD5500 page says it circulates the air in 1,043 square feet four times an hour and lists a smoke CADR of 556 CFM. AirDoctor's AD3500 page lists a weight of 18 pounds. AirDoctor's AD5500 page lists a weight of 33 pounds. By those figures, we suggest the AD2000 for a bedroom or office of up to about 300 square feet, the AD3500 for a room of up to about 630 square feet, and the AD5500 for an open area of up to about 1,000 square feet.
Why the Amazon room sizes look bigger
The Amazon listing for the AD2000 says it cleans 305 square feet in 15 minutes and up to 1,220 square feet in one hour. The Amazon listing for the AD3500 says it cleans 630 square feet in 15 minutes and up to 2,520 square feet in one hour, and its title says up to 2,520 square feet. By our arithmetic, the hour figure is exactly four times the 15-minute figure, so it describes one air change an hour rather than four. The EPA says the higher the CADR, the larger the area an air cleaner can serve, that CADRs are calculated for an 8-foot ceiling, and that rooms with higher ceilings call for a unit sized for a larger area. Read the four-changes figure on AirDoctor's pages when sizing.
AD3500 or AD4000
AirDoctor's AD4000 page lists room coverage up to 694 square feet at four air changes an hour and a smoke CADR of 370 CFM. AirDoctor's AD3500 page says it circulates the air in 630 square feet four times an hour and lists a smoke CADR of 340 CFM. In this snapshot the AD4000 costs $216.00 more than the AD3500 for 64 more square feet and 30 more CFM of smoke CADR. AirDoctor's AD4000 page says to replace both the UltraHEPA and carbon/VOC filters every 6 months. AirDoctor's AD2000 page lists three filter stages (pre-filter, carbon/VOC and UltraHEPA), a carbon/VOC filter change every 6 months and an UltraHEPA change every 12 months. We suggest the AD3500 for most rooms; the AD4000 makes sense when the price gap is much smaller than in this snapshot.
Another brand we checked
We also checked one rival from another brand. Coway lists the Airmega 400 at 1,560 square feet at two air changes per hour, with a CADR of 328 for smoke. Because Coway uses two air changes an hour and AirDoctor uses four, the headline square footage of the two brands cannot be compared directly; compare CADR instead.
FAQ
Which selected offers are current?
4 current offers are confirmed for the selected products: $368.10–$899.10. These are automatic discounts; no code is required.
Which AirDoctor is right for a bedroom?
We suggest the AD2000: AirDoctor's page says it circulates 305 square feet four times an hour, so it suits a bedroom or home office of up to that size.
Why does Amazon say the AD3500 covers 2,520 square feet?
Its listing says it cleans 630 square feet in 15 minutes and up to 2,520 square feet in one hour, so by our arithmetic the larger number is one air change an hour. AirDoctor's own page sizes it at 630 square feet at four changes an hour.
How often do AirDoctor filters need replacing?
The AD2000 page lists the carbon/VOC filter every 6 months and the UltraHEPA every 12 months; the AD4000 page says both filters every 6 months.
Sources and method
The AirDoctor AD2000 page , AirDoctor AD3500 page , AirDoctor AD4000 page , AirDoctor AD5500 page , Amazon AD2000 listing , Amazon AD3500 listing , EPA guide to air cleaners in the home and Coway Airmega 400 page were checked October 25, 2026 UTC. Offer values are dated feed observations collected at 12:45 UTC. We have not tested these products ourselves; performance figures are manufacturer ratings.