Clean Air Delivery Rate or CADR rating is the most important metric when you choose an air purifier.
You need to select your air purifier by the CADR rating for different-sized rooms and indoor air quality conditions. This advanced CADR calculator will help you to find out the minimum required CADR to select an air purifier for your room.
CADR Calculator for Air Purifier:
Here is the formula: CADR = [(ACH x L x W x H) / 60] cfm, and
CADR = [(ACH x L x W x H) / 60) x 1.699] m³/h
CADR or Clean Air Delivery Rate represents an air purifier’s efficiency (not effectiveness) similar to a car’s horsepower. It Indicates how fast an air purifier can filter the whole air (volumetric) of a room within a specific time.
For example, A CADR of 200 cfm (cubic feet per minute) means it can deliver 200 cubic feet of air in every minute on its highest fan speed settings. It also can be expressed as the cubic meter per hour (m³/h).
The term ‘Clean’ means the filtered air and not the quality of the filtration. The ability to trapping airborne pollutants depends on filter types. A True HEPA grade filter can capture 0.3-micron size airborne particles with a 99.97% efficiency.
Check out our reviews:
Should I be Concerned about CADR?
For judging an air purifier on efficiency-wise, the CADR rating is the key point you need to know. To get effective air cleaning, you have to check on the other aspects like filter types, filter surface area, efficient air intake-outlet design, and of course, you have to use it properly.
In a nutshell,
Air Purifier Efficiency = CADR ratings
Air Purifier Effectiveness = Types of filters
Please read our article on using an air purifier correctly to get the most out of it.
AHAM, Association of Home Appliance Manufacturers, tested and certifies air purifiers with three different CADR ratings: Tobacco Smoke, Dust, and Pollen. Tobacco smoke CADR represents the efficiency against fine particles, and the Pollen CADR means the efficiency against the larger particles comparatively.
Tobacco Smoke CADR Calculator:
AHAM CADR Certificate Seal:
To find out the required Tobacco Smoke CADR, divided your room area (sq ft) by 1.55 (AHAM’s 2/3 Rule). For example, if you have a 15 ft x 20 ft room (8 ft ceiling), then the room area is 300 sq ft. So, the minimum required Tobacco Smoke CADR is 300 / 1.55 = 194 cfm.
Here, you can find the list of AHAM-certified air purifiers with room size recommendations. However, AHAM verification is not a must-have thing when you are going to buy an air purifier. The certification will give you some extra validation.