What Does CADR Actually Mean on an Air Purifier Box?

If you have researched air purifiers, you have probably seen the letters CADR near the specifications. This one number can help tell you whether a purifier will work well in your room or barely keep up.

What Does CADR Stand For?

CADR stands for Clean Air Delivery Rate. It indicates how much filtered air a purifier can deliver, commonly measured in cubic feet per minute (CFM) or cubic metres per hour (m³/h). Ratings may be shown separately for dust, pollen, and smoke. A higher number generally means the purifier cleans the room faster.

Why Should I Care About This Number?

CADR helps you judge whether a purifier can move enough clean air for your room size. A large, loud machine can still have a low CADR, while a smaller unit may deliver clean air faster. Checking the rating replaces guesswork with a useful performance measure.

My Room Feels Stuffy Even With the Purifier On. Why?

The purifier may be undersized. If it is designed for a much smaller room, it can run continuously without catching up with new pollutants. This is often a room-size and CADR mismatch rather than a fault in the machine.

How Do I Match CADR to My Room Size?

A commonly used guide is to choose a smoke CADR in CFM that is at least two-thirds of the room's area in square feet. For example, a 150 sq. ft. room needs roughly 100 CFM. Always check ceiling height, the manufacturer's stated test conditions, and your desired air changes per hour; when between sizes, round up.

Does a Higher CADR Always Mean a Better Purifier?

Not by itself. CADR tells you about delivery speed and coverage, not every aspect of filtration quality, noise, energy use, or gas removal. Look for a strong CADR together with a proper HEPA-grade filter and activated carbon when odours or VOCs matter.

How Do I Avoid Getting Confused While Shopping?

• Measure the room's length and width to calculate its square footage.
• Choose a CADR that meets or exceeds the room's requirement.
• Confirm that the purifier uses appropriate HEPA and carbon filtration.
• Compare noise, filter replacement costs, and energy use for the speed you will run most often.

What Should You Do Next?

If your purifier runs all day but the room still feels stuffy, check its CADR against the actual room size. EnviroTech's Olivia 300 is intended for smaller rooms such as bedrooms and cabins, while Olivia 700 is designed for larger spaces such as living rooms, open offices, and waiting areas.