When it comes to buying an air purifier, a common question arises: "Can this air purifier really clean the air in my entire room?" Unfortunately, the answer is not as clear-cut as manufacturers' claims might suggest.
In an industry that lacks official standards in New Zealand, some brands overstate their product's capabilities, leaving you with a machine that's not up to the task.
What's coming up:
- Air Purifier Room Sizes: Many manufacturers' suggested room size claims should not be believed.
- CADR Explained: Luckily we have an industry-standard measurement for air purifier effectiveness you should use instead.
- Unregulated New Zealand Market: Understanding the implications of the lack of official air purifier standards.
- Comparing Air Purifier Brands: The truth behind their CADR ratings and actual performance.
- Honourable Competitors: Acknowledging brands that maintain integrity with accurate figures.
Unveiling the Truth Behind Air Purifier Room Size Claims
The Heater Analogy: A Case of Selective Marketing
Imagine purchasing a heater rated for spaces up to 50m². You place it in your living area, expecting it to create a nice cosy environment. Unfortunately the warmth falls short of what you'd expect. The heater, it turns out, is only powerful enough to increase the temperature by a couple of degrees in a space that size. To achieve the comfort promised, it would be better suited to a 20m² area. This scenario mirrors the tactics used by some air purifier brands: the product might technically work in the advertised room size, but the level of purification is inadequate for the intended use.
What is CADR and Why Does it Matter?
Clean Air Delivery Rate (CADR) is the amount of filtered air volume an air purifier delivers. Measured in cubic meters per hour (m³/h) in New Zealand, CADR is the industry standard way to judge effectiveness. However, if you can't find this number, it's possible the manufacturer is intentionally obscuring less-than-ideal performance.
How to calculate the required CADR for a room
To calculate the required CADR for a room, you'll need to know the room's size, ceiling height, and desired Air Changes per Hour (ACH). Multiply the room size by the ceiling height to get the room volume, then multiply the volume by the desired ACH (typically at least 3) to get the required CADR.
A simple rule of thumb for CADR calculation
As a quick rule of thumb, multiply the room's area (in square meters) by 7.5 to estimate the required CADR. This method provides a rough estimate for most residential situations.
This is also in line with generally accepted standards overseas, such as AHAM in the USA and GB-18801
See further details here
The Wild West of Air Purifier Standards in New Zealand
A Market Without Regulation
In the absence of official standards, air purifier recommendations in New Zealand are a mixed bag. Companies are free to claim almost anything, which can mislead well-intentioned customers.
It gets more interesting when you look at these air purifiers being sold in other countries, where they often are required to use these standard ways of calculating room sizes. This suggests to us its not through ignorance that they inflate their figures here, but a deliberate attempt to mislead customers.
Comparing Brands: The Good, the Bad, and the Ugly
Based on using the standard calculations used overseas, there's some fairly stark differences between what some air purifiers claim, vs their actual effectiveness.
Above are examples of some the worst ones in the NZ market, where their effectiveness is less than half of what they state. We've looked at dozens of models sold in NZ, and have been able to break down how much each brand on average inflates their room sizes compared to the benchmark (current as at November 2023).
Our findings show while a handful of companies provide realistic room sizes in New Zealand, unfortunately most inflate their numbers by quite significant amounts!
*Based on standard calculations used overseas, dividing CADR by 7.5 to get effective room size coverage
The Ugly:
We couldn't even fit this on our chart!
The prize for the most misleading unit goes to the i-air Pro. Which with a Clean Air Delivery Rate of 600m³/hour, claims to be suited for spaces up to 500m². This is a whopping 6.25x the room size it should be used in!
Our Commitment to You
Balancing Business with Honesty
While we offer a range of air purifiers for sale, our commitment goes beyond just business. We aim to provide accurate and transparent information about each product and the air purifier market. Our goal is not just to sell, but to ensure that you find the air purifier that truly fits your needs. Whether it's one we sell, or a worthy competitors!
