HEPA and ULPA

http://www.ultraclean-cn.com/ 2006-9-27 11:04:54
[Brief] HEPA (High Efficiency Particulate Air Filters):the HEPA has to achieve two important technique indexes: one is the minimum purifying particles must reach 0.0001mm, the other is the purification efficiency reaches more than 99.97%. Only these two indexes achieved;ULPA (Ultra Low Penetration Air). ULPA filter technology has the efficiency for removing airborne allergens; removing 99.99% of airborne particles as small as 0.1 micron...
In recent years our awareness of how the quality of the air we breathe affects our general health has been heightened. High filtration efficiencies are very important to all of us, especially those who suffer from dust related sensitivities. Improving the quality of the air we breathe can be important to our general health. Most high efficiency HEPA and ULPA filters gives the user the assurance that the stated specification is actually being achieved by the filter.
 
HEPA (High Efficiency Particulate Air Filters)
From the point of purification technology, the HEPA has to achieve two important technique indexes: one is the minimum purifying particles must reach 0.0001mm, the other is the purification efficiency reaches more than 99.97%. Only these two indexes achieved, it can be called HEPA., otherwise, it can only be called ordinary filters
HEPA purification principle: It is formed by electrostatic fiber irregularly close interweaving. It can effectively capture the particles less than 0.0001mm and the purification efficient rate can reach more than 99.97%.
HEPA has the powerful filtration ability mainly on smoke, dust, pollen and bacteria. It can effectively remove radioactive dust from plant exhausts without redistribution.
 
ULPA (Ultra Low Penetration Air).
ULPA filter technology has the  efficiency for removing airborne allergens; removing 99.99% of airborne particles as small as 0.1 micron.
The difference between HEPA and ULPA
1. Different requirement on materials: HEPA use two kinds of materials: one is electrostatic PP fiber, the other is electrostatic fiberglass. ULPA only adopts electrostatic fiberglass.
2. Different Purification efficiency: HEPA  filtration efficiency only need to reach 99.97%, but ULPA need to have an efficiency rate more than  99.99%
3. Different cost: ULPA has a high technique requirement on material because its purification rate nearly reaches 100%, the cost is higher 30% than HEPA