With the increasing concern about air quality, more and more homes and offices have begun to install fresh air systems to ensure fresh and healthy indoor air. The fresh air system removes harmful substances in the outside air through the filter, such as PM2.5, pollen, bacteria, mold, etc., to keep the fresh circulation of indoor air. However, with the extension of use time, the filter will gradually accumulate a large amount of dust and impurities, affecting the performance of the fresh air system. Therefore, regular replacement of the filter is the key to ensure the efficient operation of the fresh air system.

This article will describe in detail how to correctly replace the filter of the fresh air system to help users maintain the equipment and improve air quality.

First, the role of the fresh air system filter

The filter of the fresh air system is one of its core components, which mainly plays the following roles:
1. Removal of harmful substances: the filter can effectively intercept harmful substances such as PM2.5, dust, pollen, and bacteria in the air to prevent them from entering the indoor air.
2. Improve air quality: The filtered air is fresher, which helps to improve indoor air quality and reduce health problems such as allergies and respiratory diseases.
3. Extend the life of the equipment: Keeping the filter clean can reduce the accumulation of dust inside the equipment, thereby extending the service life of the fresh air system.
Second, the type of fresh air system filter
Fresh air systems are usually equipped with multi-layer filters, different filters have different functions, common filters include:
1. Primary filter: This is the most common filter, mainly used to filter large particulate matter in the air, such as dust, hair and so on.
2. Medium effect filter: used to filter small particles, such as pollen, mold, smoke, etc.
3. High efficiency filter (HEPA filter) : can filter smaller particles, such as PM2.5, bacteria, viruses, etc., which has a great effect on indoor air quality.
4. Activated carbon filter: used to absorb harmful gases in the air, such as formaldehyde, TVOCs and so on.

The replacement cycle of each filter is different, in general, the replacement frequency of the primary and medium effect filters is higher, and the HEPA and activated carbon filters need to be replaced in time according to the actual use.

When to replace the filter of the fresh air system?
1. Use time: Most fresh air system filters will have a recommended use time, usually 6 months to 1 year. The specific replacement time depends on the use of the home, the air quality in the area and the frequency of use.
2. Obvious dirt: If there is obvious dust accumulation, stains or other pollutants on the surface of the filter, it indicates that the filter has begun to fail and should be replaced as soon as possible.
3. Abnormal operation of the system: If the air volume of the fresh air system becomes smaller or the noise increases, it may be caused by the filter obstruction, then it is necessary to check and replace the filter.
4. Decline in air quality: If the indoor air quality suddenly deteriorates, especially after the haze weather, it may be that the filter is full and can not effectively filter harmful substances.
Fourth, how to replace the filter of the fresh air system?
Replacing the filter of the fresh air system is actually a relatively simple process, and most users can do it themselves. The following are the steps to replace the filter:
1. Prepare
Before replacing the filter, prepare the following tools and materials:
• New filter (purchased according to original filter model)
• Screwdriver (may be required depending on model)
• Clean cloth or gloves (to avoid finger grease contaminating the new filter)
2. Power off and shut down the device
For safety reasons, before replacing the filter, first make sure that the power supply of the fresh air system has been cut off. Find the power socket and turn off the power switch to avoid accidents during operation.

3. Open the device cover
Most fresh air system filters are hidden in the equipment housing, the specific operation can refer to the manual. Usually, the housing will have a screw or snap design. Use a screwdriver to remove the cover or press the buckle to gently open the outside of the device.
4. Take out the old air filter
Locate the filter that needs to be replaced. According to the design of the fresh air system, the filter can usually be easily slipped out or pulled out. Gently remove the old filter to prevent dust from spreading. At this time, you can observe the degree of dirt on the air filter to determine whether it needs to be replaced.
5. Clean up the system
After removing the old filter, use a clean cloth to clean the dust and debris inside the device. In particular, dust accumulation in fans and air intakes may affect the operation effect of fresh air systems.
6. Install a new air filter
Place the new air filter into the device in the original position. When installing, ensure that the direction of the filter is correct and tightly fitted, without leaving gaps. Different models of fresh air systems may have different installation methods, so it is necessary to operate according to the instructions in the installation.
7. Close the cover and power on
After installing the new air filter, close the device housing and ensure that the screws or fasteners are secured. Reconnect the power supply, start the fresh air system, and check its operation. At this point, you can hear the wind power of the device return to normal, and the system should function smoothly.
8. Get regular checkups
After replacing the air filter, it is recommended to periodically check the working status of the fresh air system. It can be determined by the air quality monitoring equipment installed or the air freshness of the home whether the system needs further cleaning and maintenance.
Precautions

1. Choose the right filter: When replacing the filter, be sure to choose the model and specification compatible with your fresh air system. You can obtain a suitable replacement by referring to the original air filter model or contacting after-sales service.
2. Regular maintenance: Although the filter of the fresh air system needs to be replaced regularly, it can also be cleaned regularly. Most of the primary and medium effect filters can be cleaned and used again. When cleaning, it is recommended to use a vacuum cleaner to gently absorb dust and avoid using water.
3. Follow the manufacturer's recommendations: Different brands and models of fresh air systems will have different maintenance requirements, so it is recommended that users replace the filter according to the recommendations in the product manual.
Vi. Conclusion
Replacing the filter of the fresh air system is a necessary and simple maintenance work, by regularly replacing the filter, you can ensure that the fresh air system efficiently freshen the indoor air and ensure a healthy living environment. Although the process of replacing the filter is simple, it is also necessary to pay attention to the operational details to ensure the long-term stable operation of the fresh air system.