What is the HEPA filter?Baidu encyclopedia explains: HEPA (High efficiency particulate air Filter), the Chinese meaning for High efficiency air Filter, reach the standard HEPA filters, for 0.1 mm and 0.3 mm of efficiency reached 99.7%, HEPA net is the feature of air can pass, but cannot pass tiny particles.
In short, HEPA is a high-density filter.It belongs to a kind of passive air purifier, mainly through the fan, screen, will be greater than 2.5 micron particulate matter in the air, dust, bacteria, viruses, effectively intercept, the advantages of HEPA filter filtering effect is obvious, but the use of material loss is very big, need to be replaced in a timely manner, if not timely replacement, can instead make interception on the screen of bacteria and viruses, the formation of secondary pollution.So how long does it take to replace the HEPA? Is there a general estimate?
HEPA filter from white is black then must be replaced, generally replaced once half a year, change of program is also very simple, as long as open the lid of the side, replaced the old filter can, general air purifier has two layers of filter, a layer of HEPA filter efficiently, a layer of activated carbon filter.Some filters will combine these two layers into one layer, commonly known as composite filters.
Air purifiers can be divided into active air purifiers and passive air purifiers according to different working principles.Principle of active air purifier is effective and active release into the air purification sterilization factor, through the air, the diffusion characteristic, to reach every corner of the indoor no dead Angle of air purification effect.Passive air purifiers are mainly used to pump air into the machine, and then filter the air through a built-in filter to filter dust, odor and disinfection.
The filter type air purifier is mainly used to process air by using HEPA filter + activated carbon filter + photocatalyst (cold catalyst, multi-contact) + ultraviolet sterilization and electrostatic adsorption filter.The HEPA filter has the effect of filtering particulate matter, and the active carbon and other substances are mainly toxic and harmful substances such as adsorption odor.
From the point of two kinds of purification efficiency, active use of the characteristics of the air diffuse, the purification factor to spread to every corner of air purification, and active air purifier get rid of the limitation of the fan and mesh, don't have to passively wait for air is pumping in again after filtered again through the fan.But most of passive air purifier can only put a small piece of space in air purifiers produce certain purification effect, only through a long time after all indoor air filter again.Purely from the purifying effect, the active air purifier is superior.However, the more obvious the active ionic generator is to the smaller particles, the more obvious the purification effect of the larger particles such as hair and dust.