Why You Can’t Trust CADR Ratings When Comparing Air Purifiers

When you're shopping for an air purifier, you’ll inevitably see the acronym CADR—Clean Air Delivery Rate. This rating, often presented as the gold standard for comparison, promises a simple way to judge a purifier's performance.

But here’s the truth: CADR ratings can be misleading. They don’t tell the full story about an air purifier’s performance, real-world effectiveness, or long-term air quality benefits.

At INOVA Air Purifiers, we believe in transparency and long-term results — not just lab numbers. Let’s explore why CADR ratings shouldn’t be your only measure when choosing an air purifier.

1. CADR Tests Are Conducted in Unrealistic Conditions

CADR testing is performed in a small, sealed room — typically around 28.5 cubic meters — with constant air circulation and short test durations (about 20 minutes).

These lab conditions don’t reflect real homes, offices, or medical environments, where air circulation, humidity, and particle sources are constantly changing.

In the real world, an air purifier’s ability to maintain consistent filtration over time is far more important than how fast it cleans a tiny sealed room.

2. CADR Doesn’t Account for Particle Size Effectiveness

CADR ratings focus on just three particle sizes:

• Smoke (0.09–1 micron)

• Dust (0.5–3 microns)

• Pollen (5–11 microns)

However, some of the most dangerous pollutants — like ultrafine particles, bacteria, viruses, and volatile organic compounds (VOCs) — are much smaller than what CADR measures.

A purifier with a high CADR score might perform well on larger particles but fail to effectively capture the tiniest, most harmful ones.

INOVA Air Purifiers, for example, use medical-grade HEPA filters that trap particles down to 0.3 microns and smaller, ensuring comprehensive protection that CADR tests simply don’t measure.

3. Filter Quality and Longevity Are Ignored

CADR testing is performed using new filters only. It doesn’t take into account how quickly performance drops as the filter becomes loaded with particles.

Some air purifiers achieve a high CADR score initially, but their performance declines rapidly — especially if they rely on thin or low-quality filter media.

INOVA’s multi-stage filtration systems are engineered for long-term efficiency, with large-capacity filters that maintain airflow and filtration performance for years, not months.

4. Noise and Airflow Are Not Factored In

To achieve a higher CADR score, some manufacturers simply increase the fan speed — which boosts airflow but also increases noise.

While this may improve the CADR number on paper, it’s not how most people use their purifiers day-to-day. Most users operate at medium or low settings for comfort and energy efficiency, where CADR no longer represents actual performance.

INOVA air purifiers are designed for quiet, consistent operation, delivering high clean air performance even at lower fan speeds.

5. CADR Doesn’t Measure Chemical or Gas Removal

CADR focuses solely on particulate removal — not gases, odours, or chemical pollutants.

If you’re dealing with issues like formaldehyde, vehicle emissions, or cooking odours, a high CADR purifier may not make a noticeable difference.

That’s why INOVA air purifiers integrate activated carbon filtration, designed to capture gases, VOCs, and odours — ensuring a cleaner, healthier indoor environment overall.

The Bottom Line: Real-World Air Quality Matters More Than a Number

While CADR can provide a rough benchmark, it’s not a comprehensive measure of an air purifier’s effectiveness, especially for long-term use or in challenging environments.

When choosing an air purifier, look beyond CADR. Consider:

• Filter quality and size

• Particle and gas removal capability

• Airflow design and coverage area

• Noise levels and energy efficiency

• Real-world, long-term performance

At INOVA Air Purifiers, we design our systems for true, measurable improvement in indoor air quality — not just for lab tests, but for real living and working spaces.

Explore our range of INOVA Air Purifiers today and experience what genuine, long-term clean air feels like — beyond the numbers.