How to maintain the HEPA filter

We all know that the principle of the general mainstream purifier is to use a fan to suck in the surrounding air, and then the air is filtered through the HEPA filter to discharge fresh air. But do you know why the HEPA filter cannot be washed?

1: What are the disadvantages of washing the HEPA filter?

In an air purifier, the resistance and air volume are no longer in a linear relationship, but an upward arc. When the air volume increases by 30%, the resistance may increase by 50%. The HEPA filter can capture any form of particulate matter, including liquid droplets. Therefore, if water is used for flushing directly, the resistance will reach several times the ventilation volume. The result is that while washing away the dust particles, the gap of the HEPA filter will also become larger, which directly causes the diameter of the filter to become larger, which seriously affects the filtering effect. In addition, most air purifiers currently use paper-like filters, which will be severely deformed after washing with water, lose precision, and have poor filtering effects.

2: Is it useful to use a vacuum cleaner?

Many people propose to use the "shaking off" method to remove dust. Although it has a certain effect, shaking and sucking with a vacuum cleaner can remove some large particles of dust, but small particles will settle in HEPA. The fine particles will eventually block the micropores on the filter screen, causing the resistance to increase, the air volume to reduce, and the noise to increase. It's time to change the filter, there is no other way.

3: Why is there a HEPA filter that can be washed in the market?

The material of the HEPA filter itself is generally polypropylene, or other composite materials, which belong to the paper type, so generally, it cannot be cleaned. However, some air purifier products do claim to clean HEPA filters with water. So how to do it?

As we know, this kind of products that are claimed to be able to clean the HEPA filter is not much different in the material of the HEPA filter, but it does some waterproof treatment on the surface of the filter so that it can play a role when it is washed with water. But it should be noted that even so, it is only limited protection for the HEPA filter, and frequent washing will still significantly weaken the filtering effect. According to research, even if the HEPA filter can be cleaned, after 20 cleanings, its filtration effect is only 60% of the new filter. Therefore, even an air purifier that can be cleaned needs to be operated carefully, and the number of cleanings should be strictly limited.

Therefore, in general, it is the water washing function obtained by reducing the adsorption capacity, which is not completely recyclable without loss.

4: Why can the HEPA filter of the vacuum cleaner be washed with water but not the air purifier?

The materials are different. HEPA cannot be washed with water. The HEPA materials of industrial vacuum cleaners are mostly blends of glass fiber, polyurethane, and other materials. Washing will have a certain impact on the material. Originally, HEPA is used for high-efficiency filtration, and washing will cause precision. Therefore, it is not recommended to wash with water (it is not ruled out that some HEPA that can be washed with water are not HEPA at all, and BIA certification can be requested for verification).