Can An Air Purifier Filter Last For 10 Years?

One of the least understood things about room air purifiers is how long a filter lasts before it needs to be replaced. The answer is – it’s not very straightforward, and the manufacturer’s recommendation is not something that you could blindly follow.

In this blog post, we take a deep dive into how manufacturers decide the estimated lifespan of an air purifier’s filter.

How do manufacturers calculate the estimated lifespan of an air purifier’s filter?

There are three variables that are used in order to calculate the estimated lifespan of an air purifier’s filter.

They are:

1. The amount of filtration material that the filter contains
2. The Clean Air Delivery Rate and speed setting of the air purifier
3. The average PM2.5 concentration of the room an air purifier is in after it runs for at least two to three hours

A mathematical formula is then used to calculate the number of hours a filter will last, which could then be used to estimate how long it could be used for.

For example, if the estimated lifespan of a filter is 5,000 hours, the manufacturer could claim that their filter lasts for 7 months (based on 24 hours of daily usage) or over 2 years (based on 8 hours of daily usage).

The big issue, however, is that most manufacturers would not reveal how the estimated filter lifespan was calculated – for instance, a manufacturer that claims that their filter could last for 2 years may decide to withhold the fact that it was calculated according to 8 hours of usage a day.

This formula is based on the industry benchmark of how long it takes for an air purifier’s Clean Air Delivery Rate to be halved (drop by 50%) before it needs to be replaced.

Usually, it is in the manufacturer’s interest to provide an estimate that fits the use case of most of its customers. We will soon see in the next section how certain values could be skewed in order to give customers the impression that their filters last far longer than others.

Can a filter really last for 10 years?

Some Japanese companies, such as Sharp and Daikin, claim that their filters could last for 10 years, giving customers the impression that they don’t have to replace them for that amount of time.

Technically speaking, it’s possible to use the same filter for 10 years if all of the following conditions are strictly met:

• The air purifier is used on a very low speed setting (such as sleep mode) all the time for 10 years
• The air purifier has a relatively high Clean Air Delivery Rate (CADR) at maximum speed (at least 600 m³/h)
• The air purifier contains a decent amount of filtration amount that matches the CADR mentioned above
• The average PM2.5 concentration in the room is assumed to be in the low single digits (1 to 3 µg/m³) all the time for 10 years
• Environmental conditions outdoors stay consistently the same for 10 years (i.e. no natural and man-made pollution outdoors)

As noted on Sharp’s Japanese website, the dust filter (equivalent to a High Efficiency, HEPA, or MERV filter that collects particulate matter) of their air purifiers, which Sharp claims to have an average 10 year lifespan, would have to be replaced in the matter of “several weeks to several months” depending on how and where its used, especially when there is a smell being emitted from the filter.

In fact, Japanese users of these air purifiers have questioned whether the 10 year lifespan is actually true in real world scenarios. Across various Yahoo Chiebukuro (Q&A) pages, actual users of these air purifiers all say the same thing – the 10 year lifespan is either “the very, very best case scenario” or “absolutely impossible in the real world”, and in reality, the filter needs to be replaced much sooner rather than later, even in places where no one is smoking or grilling meat, activities which produce high levels of PM2.5.

It is also worth noting that even if you try to use the same filter for 10 years, the potential drawback would be that if the air-cleaning performance of the air purifier is very weak at the lowest speed and it’s used in a large room that makes the number of air changes per hour (ACH) very low (under 3 ACH), the air will not be as clean as having a higher number of air changes, such as 6 ACH.

What should you do, then?

Take the estimated filter lifespans from the manufacturer with a grain of salt, especially if the lifespan is outrageously long (such as 3 to 10 years) and it has a low CADR at maximum speed. This is because we don’t know the variables they’ve used to calculate the estimated filter lifespan – it’s easy to skew the numbers and make it seem that the filter lasts for a very long time.

If you’re using an AirFanta room air purifier, we have one piece of good news – you can estimate the lifespan of your filters according to the amount of time you actually use it, the speed setting of your air purifier, and the average PM2.5 concentration in your room after it’s left running for two to three hours with our free filter lifespan calculator.

Learn more about how you can use this calculator below:

How To Use The Filter Lifespan Calculator For AirFanta Room Air Purifiers

Purchase safe and highly effective room air purifiers

If you are looking for a safe, reliable, and good air purifier that delivers a high amount of clean air at a reasonable price, consider room air purifiers from AirFanta, which have the following key selling points:

• Delivers up to 3x more clean air than major brands in the same price range
• Consumes up to 3.6x less electricity than products with similar air-cleaning performance
• Relatively quiet between 29 dB to 55 dB
• Safe for everyone, including babies and pets – no ions, no ozone, no UV

Purchase AirFanta room air purifiers below or click here to learn more on our discovery page.