Updated October 2026US pricing Independent
AD2000 Vs AD3500 Vs AD5500: Which AirDoctor Is Right
Three models, three very different running costs. Here is the comparison on the numbers that decide it — and the filter compatibility trap that catches most buyers.
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Straight Answer First
Pick The AD3500
- Living room, large bedroom or a open-ish 400–600 sq ft area at a real 4 air changes per hour.
- You want the separate carbon/VOC and UltraHEPA stages, not a single combined cartridge.
- Filter bill of roughly $178 a year as a combo pack is acceptable.
- This is the volume seller for a reason — it is the sweet spot of the range.
Pick The AD5500 Only If
- You are treating a genuinely open-concept floor, not one closed room.
- You accept roughly double the filter cost — about $319–$344 a year.
- Buying one AD5500 beats buying two AD3500s for your layout. Often it does not.
- For a single bedroom the AD2000 does the job at a fraction of both costs.
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Head To Head
| AD2000 | AD3500 | AD5500 | |
|---|---|---|---|
| Built for | Small & medium rooms, bedrooms | Living rooms, large bedrooms | Extra-large & open-concept |
| Filtration stages | 3-stage | 4-stage | 4-stage, dual filter set |
| Carbon / VOC filter | Combined with UltraHEPA | Separate filter | Separate, two of them |
| Air quality sensor | On 2000i | Yes | Yes |
| Wi-Fi / app | 2000i only | 3500i only | 5500i only |
| Approx. unit price | ~$399 (2000i ~$459) | ~$419–$559 (3500i ~$609) | ~$999 |
| Approx. filter cost / year | ~$120–$140 | ~$178 combo pack | ~$319–$344 combo pack |
| Takes filters from | AD2000 series | AD3500 set (also fits AD3000) | AD5500 set (also fits AD5000) |
US retail figures observed October 2026, rounded. AirDoctor's direct pricing and promotions often differ from marketplace listings.
Where The Model Numbers Get Confusing
AD3000 versus AD3500. The AD3500 is the reworked version of the original AD3000. The cabinet, the fan arrangement and the four-stage design are essentially the same unit. The practical difference is the filter set: AD3500 filters fit both machines, but original AD3000 filters will not fit an AD3500. If you are buying new, there is no reason to hunt down an AD3000.
AD5000 versus AD5500. Same relationship. AD5500 filters fit both; AD5000 filters do not fit the 5500.
The "i" models. AD2000i, AD3500i and AD5500i are the same hardware with Wi-Fi and app control added, at roughly $50–$60 more. If you will never open the app, skip it — the physical controls and the auto mode work identically without it.
The AD4000. This one sits outside the pattern. It uses a single all-in-one cartridge instead of separate filters, so there is one part to buy but it is replaced roughly every 6 months rather than on a split 6/12-month schedule.
Judging The Coverage Claims
AirDoctor, like every brand, publishes its largest coverage figure at 1 air change per hour. That is why the same AD5500 appears as "4,172 sq ft" in one retail listing and roughly 1,040 sq ft in a testing publication — the second figure is at a far more useful air-change rate.
For allergens, pet dander, cooking smoke or wildfire season, aim for 4–5 air changes per hour. The quick rule: take the headline square footage and divide by four. That is the room size the unit will actually keep clean.
Applied to this range, the AD2000 is a bedroom unit, the AD3500 is a living-room unit, and the AD5500 is for an open floor — regardless of how large the box numbers look.
Compare Live Prices
Model availability and the current promotion are shown on AirDoctor's own site.
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Frequently Asked Questions
Is the AD3500 better than the AD3000?
They are effectively the same machine; the AD3500 is the current revision. The meaningful difference is the filter set — AD3500 filters fit both units, but original AD3000 filters will not fit an AD3500. Buy the AD3500 if you are buying new.
Is the AD5500 worth double the AD3500?
Only for genuinely open-concept square footage. You pay roughly twice for the unit and roughly twice again every year in filters. For most homes, one AD3500 in the main living space — or two AD3500s in two rooms — delivers more usable air changes per rupee spent.
Do I need the i version with Wi-Fi?
No. The 2000i, 3500i and 5500i are the same hardware with app control added for roughly $50 to $60 more. Auto mode, the air quality sensor and all fan speeds work from the physical controls without it.
Which AirDoctor is best for a bedroom?
The AD2000. It is built for small and medium rooms, costs the least to run, and at bedroom square footage it reaches a high air-change rate on a low, quieter fan setting. Putting an AD5500 in a bedroom is paying for capacity you cannot use.