Air changes per hour (ACH) refers to how many times the air is changed with new, clean air in a given space within the span of an hour. A Harvard University Study cited by the CDC recommends at least 4 air changes per hour to effectively remove allergens like smoke, bacteria, viruses, dust, and pollen.

CADR, or Clean Air Delivery Rate, refers to your air purifier’s efficiency in removing these three contaminants over time: pollen, dust, and smoke. Higher CADR numbers indicate better air cleaning performance. The smoke CADR number is most stringent, reflecting the unit’s ability to eliminate the smallest and most dangerous particles from your indoor air.

Great question! Choosing the right air purifier will depend on the size of your room and the air circulations per hour. According to the Harvard University study, 4 air changes per hour are recommended for optimal purification. AirDoctor units are designed to meet this standard.

AirDoctor 1000: Replace UltraHEPA® and Carbon/VOC filters every 6 months.

All other AirDoctor units:

• Replace Carbon/VOC filters every 6 months.
• Replace UltraHEPA® filters every 12 months.

The indicator light on your AirDoctor will also light on when it’s time to replace your filter

– no more guesswork!

We stand behind the quality of our products. That’s why we offer a 30-day money-back guarantee on all purchases. If for any reason you’re not completely satisfied with your AirDoctor, simply reach out to our friendly customer service team at 1-800-221-2515, and we’ll gladly issue you a full refund, minus shipping and processing fees.

Yes! If you’re interested in a payment plan option, just select the Affirm payment option at checkout and follow the instructions. Terms and conditions apply.**

**Various purchase plans are available based on approval. Regretfully, Affirm is NOT available in Iowa or West Virginia due to state-specific financial regulations.