The filter is the heart of every air purifier, but it does not last forever. Exactly how often it needs replacing depends on the type of filter, how much the device runs, and how polluted the air in and around your home is.
Why filters wear out
A HEPA filter captures fine dust, pollen, house dust, bacteria, and other small particles by literally trapping them in the filter material. Over time, that material becomes saturated: there is simply no more room for particles. From that moment on, the effectiveness of the filter decreases, even if the device seems to be working normally at first glance. An activated carbon layer, which captures odors and volatile substances, becomes saturated in a similar way.
A general guideline
Most manufacturers of HEPA filters assume a replacement interval of approximately 6 to 12 months with normal, daily use. If you run the device almost continuously, live on a busy road, have pets, or use the air purifier a lot during pollen season, the chances are high that your filter will become saturated faster and therefore need replacement more often. With occasional use in a relatively clean environment, a filter can actually last longer than the stated period.
Signs that a filter needs replacing
- The airflow from the device feels noticeably weaker than before, even on the highest setting.
- A strange or musty odor persists, even after the device has been running for a while.
- The filter looks clearly gray, brown, or dirty upon visual inspection.
- Any filter indicator on the device indicates that replacement is necessary.
How to keep track
Because filter wear is gradual, it is not always immediately noticeable. It helps to note the replacement date somewhere, for example in a calendar app on your phone, so that you do not have to rely on your memory. Many people set a reminder for six to nine months ahead when purchasing a new filter, and adjust it based on their own usage.
HEPA and activated carbon: not always the same rhythm
Some air purifiers work with combined filters, where a HEPA layer and an activated carbon layer are housed in a single unit, such as with the four-stage filtration of the PA244. In that case, you replace both parts at the same time, even if the odor-controlling carbon layer might become saturated faster than the HEPA section. This makes maintenance simpler: one replacement moment for the entire filter, instead of separate parts that you have to keep track of individually.
The convenience of a replacement filter
Replacing a filter on time is not only good for air quality, it is also good for the device itself. A saturated filter provides more resistance, causing the fan to work harder for the same result. Over time, this can affect both the noise level and the power consumption.
Our advice
For an air purifier that you use daily, check the condition of the filter every few months and replace it after about a year at the latest, even if there is no indicator. For the Dynter AirPure Plus PA244, the matching HEPA13 replacement filter is available separately, so you can easily restore the device to full strength yourself without having to buy a new appliance.