The replacement cycle of air filters is affected by many factors, the following is the specific introduction:
1. Classification according to the use environment
1. ** Ordinary family environment **
- ** Primary filter ** : In the air conditioning system of ordinary families, if the primary filter is only used for daily air filtration, it can generally be replaced once every 3-6 months. If you live in an area with poor air quality and dust, or if you keep pets at home, hair and dust are more, it may take 2-3 months to replace.
- ** Medium effect filter ** : For the medium effect filter used at home, it can be replaced once every 6-12 months under normal circumstances. However, if someone in the family has respiratory diseases or allergies, in order to better filter allergens and other impurities in the air, it is recommended to replace 4-8 months.
- ** High efficiency filter (HEPA) ** : HEPA filter used in home air purifiers, usually replaced once every 1-2 years. However, if the most high-grade purifier is often used or the ambient air quality is poor, such as close to factories and traffic arteries, it may take about 1 year to replace.
2. ** Commercial buildings and office environments **
- ** Primary filter ** : Generally installed in the air inlet of the air conditioning system of the primary filter, according to the location of the building and the surrounding air quality, the replacement cycle is about 1-3 months. For example, commercial buildings located in a busy area in the center of a city or near a construction site are dusty and may need to be replaced within 1-2 months.
- ** Medium Efficiency filter ** : In the air conditioning system of a commercial building, medium efficiency filter can usually be replaced every 3-6 months. However, if the building is densely populated, such as large shopping malls, office buildings, and frequent air circulation, it may need to be replaced in 3-4 months to ensure air quality.
- ** High efficiency filter (HEPA) ** : HEPA filter used in some office areas with high air quality requirements, such as senior management offices, meeting rooms, etc., should be replaced once every 1-2 years. However, in special commercial buildings such as hospitals and laboratories, the replacement cycle may be shortened to 3-6 months according to the specific cleanliness level requirements and use conditions.
3. ** Industrial environment **
- ** Initial filter ** : In general industrial ventilation systems, initial filter may need to be replaced in 1-2 weeks. For example, in places with more dust such as foundries and cement plants, due to the high content of solid particles in the air, the primary filter will soon be blocked and need to be replaced frequently.
- ** Medium efficiency filter ** : In industrial environments, medium efficiency filter replacement cycle is usually 1-3 months. For example, in the electronics factory, although there are certain clean requirements, compared with the ultra-clean chip manufacturing area, the replacement cycle can be slightly longer.
- ** High Efficiency Filter (HEPA) and ultra-high efficiency filter (ULPA) ** : In industrial environments with high air cleanliness requirements such as semiconductor manufacturing and pharmaceuticals, HEPA and ULPA filters may need to be replaced every 3-6 months according to production schedules and air quality monitoring. In some key production links, it may even be shorter, such as chip lithography areas may be replaced every 1-3 months.
### Two, according to the filter status
1. ** Resistance change ** : the air filter in the process of use, with the accumulation of impurities, its resistance will gradually increase. Filter replacement should be considered when the resistance reaches 1.5 to 2 times the initial resistance. Resistance changes can generally be monitored by pressure sensors mounted at both ends of the filter. For example, a primary filter has an initial resistance of 50Pa, and when the resistance reaches 75-100 Pa, it needs to be replaced.
2. ** Dust capacity ** : Each air filter has a specified dust capacity. When this dust capacity is reached, the filtration efficiency of the filter will decrease significantly. Different types and specifications of the filter dust capacity is different, such as a medium effect filter dust capacity of 500g, when the accumulated dust weight is close to this value, it needs to be replaced.
3. ** Appearance check ** : The appearance of the filter can be checked regularly. If the filter surface is found to be significantly damaged, deformed, or dust has penetrated the filter, then it should be replaced immediately. For example, if the filter paper of the HEPA filter is found to crack during the inspection, it must be replaced to prevent unfiltered air from entering the room.