Why CBC Marketplace needs to use modern air purifier testing

The test – Clean Air Delivery Rate or CADR – is designed around an older generation of purifier – big white boxes – which were favoured in the 1980s when homes had ceiling fans and software engineering was rudimentary. Many manufacturers still favour this test as it promotes big energy consumptive motors in white boxes, allowing them to tinker with old designs rather than invent anything new. A bigger motor, means a bigger CADR, which means a better machine goes the marketing. It is however, false.

In using the CADR test, CBC risks perpetuating the marketing myth but worse still it misleads people on the real-world performance of air purifiers. We think it’s time to set the record straight and help debunk the myths surrounding the testing of purifiers and the sole use of the Clean Air Delivery Rate (CADR) as a metric to judge superiority.

Using CADR alone as a measure of performance is like buying a car based solely on which one drives the fastest.

The reality is when buying a car you will also consider other things such as noise of the engine, durability and lifespan, safety, functionality and smoothness of ride in all conditions.

The Clean Air Delivery Rate (CADR) is simply a speed metric. It’s like the speedometer of a car. It measures how fast a purifier can clean the air in a small, controlled chamber. It is calculated by measuring how much faster a purifier removes particles from the air compared to how quickly they would naturally drop and settle on surfaces.

But knowing how fast a purifier cleans a small test chamber doesn’t help you choose the right purifier for your home. From a functional standpoint, a purifier needs to be able to filter out particles down to a microscopic level and it needs to project and circulate the clean air so it reaches every corner of the room, without relying on environmental factors, or ceiling fans.

Beyond functional abilities, consumers also need to consider real world impacts of adding a purifier to their environment such as noise level, energy use, ease of use, etc. In addition, many consumers care about additional functionality such as connectivity and multifunctionality.  Others will factor design and aesthetic into their choice. An educated consumer should not pick a purifier solely on the speed metric.

 The CADR metric is outdated

Some test methods used to achieve the CADR metric date back to the 1980s. Purification technology has advanced significantly since and the rooms these purifiers are placed in continue to grow.

CADR does not consider what airborne pollution is being filtered or how effectively. It pays no testament to the advances in filtration technology and the ability to remove nasties such as formaldehyde from the air.

It is crucial that test methods continue to evolve alongside these technological and home advancements.  Dyson regularly speaks with standards organizations across the globe to actively communicate our concerns with current test methodologies. In fact, the Chinese Household Electrical Appliances Research Institute (CHEARI) which standardizes test methods in Mainland China, the world’s biggest and most advanced purifier market, has already adopted similar test methodology to the Point Loading Auto Response (POLAR) test, Dyson’s in-house test methodology.  

A test method which is unrealistic of modern day living

While each chamber used to achieve the CADR score may be slightly different, there are flaws that run through each test.

• Room Size – The size of the test chamber ranges between 28m³ and 30m³. This is unrepresentative of the average size of a room in a real, modern home. Especially now as open concept floor plans are increasingly popular.  A machine could achieve a high CADR score based on this small chamber, but in reality the score achieved doesn’t mean the purifier is able to clean a whole room in your home as the results suggest.
• Artificial Circulation – Before the test begins, a ceiling fan is switched on to mix the pollutant in the room. During the test a wall fan is also switched on to circulate the air around the room during the test. Many homes do not have ceiling fans and those that do may not always have them turned on. It is our firm belief that the purifier itself must be responsible for circulating clean air around the room and you cannot rely on environmental factors.
  
• Max Mode – All purifiers are tested on their highest setting. In real world use, owners would rarely keep their product on this setting continuously because it could potentially waste energy and can be quite noisy. The test does not account for things like auto mode where the product would sense and react to a pollutant until it was cleared from the air.

To read more about CADR and Dyson’s preferred test methodology (POLAR) please visit https://www.dysoncanada.ca/en/newsroom/overview/updates/what-is-cadr.