the function of fresh air system filter
the fresh air system filter is quite important, it collects fine dust to improve indoor air quality and protect the heat exchange system.
Now more and more families use fresh air systems for their health, especially the health of the respiratory tract, because there is a lot of PM2.5 in the air, especially for some developing cities where the air quality is not very good.
In winter, in some northern regions, in order to maintain the indoor temperature to close doors and windows for a long time, the indoor air quality continues to decline.
Fresh air system filter make sure the air from out to indoor is purified, it makes the fresh air system available, in time replace of those filters are quite necessary.
In order to purify the fresh air and protect the sensitive heat exchanger. There are 4 types of air filters that are used popularly.
- G series primary filter
- F series medium filter
- H series HEPA filter
- C series activated carbon filter

Fresh air system filter G series
The G series primary filter can remove large particles of dust in the air and has a very good dust holding capacity. Its main function is to filter the visible dust. Because it filters out the largest dust, it can improve the medium filter and HEPA Service life.

Pre filter mat

Pleated pre filter

Flat pre filter
F Series
The medium-efficiency filter of the F series further improves the filtering level. It can effectively filter the pollen, dust, smoke and other finer particles in the air. It is also to extend the service life of HEPA. At the same time, if HEPA is not required in some fresh air systems, Then it will serve as the final filter.
There are two designs. The first is a mini pleat filter, which maximizes the filter area while reducing installation space. The second type is a bag filter, which has a very good dust holding capacity and has a very good effect for some areas with poor air quality.

F7 F8 Fine filter

F7 F8 Pocket filter
H Series
The last level is HEPA, which has a filtration level of more than 99%. For 0.3 micron particles, it can completely protect the heat exchange of the fresh air system to a large extent, while maximizing the indoor air quality.

Cardboard HEPA

Metal frame HEPA
C Series – Carbon fresh air system filter

Carbon particle filter