WHY IS AIR PURIFICATION REQUIRED?
PURIFICATION
There are many different types of filters available on the market today. Particulate filters can be classified into 5 basic categories. To scroll directly to a particular filter type, click on one of the following 5 selections. The page will automaticaly scroll to it's destination.
1. LOW EFFICIENCY FILTERS
Most Low Efficiency Filters are pad or panel type filters, with average filter efficiency reaching 30%. These filters remove large particles, usually 10 microns or larger. Ideal application is light residential.
2. MEDIUM EFFICIENCY FILTERS
Medium Efficiency Filters can be in the Form of a bag type or box type lifter, with an average efficiency ranging between 40% to 60%. These Medium Efficiency Filters effectively remove particles in the 3.0 to 10.0 microns in range. These filters are usually pleated allowing for a much greater surface area which significantly increases the filter’s longevity while reducing pressure drop.
This filter is usually a flat, large surface pleated filter with an aerodynamic design and superior filtering capacity. The alignment of the pleats ensures consistent airflow through the filter. Its design increases its filtering surface as air passes through the media on each side of the pleats. The larger dust particles are usually trapped at the bottom of the pleats, while the smaller ones collect on the sides.
Medium Efficiency PLEATED Odor Filters
A pleated activated carbon filter has the same Dust removal features as MEDIUM EFFICIENCT FILTER mentioned above, however this filter features a flameproof cardboard frame and carbon impregnated filter media, which is laminated and pleated. This filter is the perfect solution to eliminate light odors caused by gases, cigarette smoke, etc.
3. HIGH EFFICIENCY FILTERS
High Efficiency Filters can be in the form of a bag type or box type filter. with an average efficiency ranging between 80% to 90%. These High Efficiency filters effectively remove particles 1.0 microns and larger.
Filter media is made of ultra fine fiber. Aluminum separators between each pleat ensure a longer life to the filter. It can be available in three efficiency levels: 60-65%, 80-85% and 90-95%, 6 or 12-inch thick.
4. HEPA FILTERS
HEPA (High Efficiency Particulate Absolute) Filters are designed to capture sub-micron particles that would tend to pass straight through traditional Ashrae rated ventilation filters. These microscopic particles can come in the form of smoke, powders, aerosols, metal fumes, bacteria, mold and lung spores. HEPA Filters are extremely critical in order to provide a safe working environment where small particulate matter is generated. It is these sub-micron particles that escape the human built-in filtration system and as a result can make their way deep into our lungs where they cannot be expelled, causing long term health concerns. It is For this reason that allergists, asthma specialists and air filtration specialists alike, recommend the use of HEPA filtration to provide healthy environments.
HEPA filters are also used to protect sensitive electronic equipment by introducing extremely clean air over the working
environments. By doing this we reduce the impact that the particulate matter can have on the micro circuitry of today’s
sophisticated machinery. Essentially as electronic equipment becomes smaller it also becomes more susceptible to its’
environment.
All HEPA Filters are rated and tested against the same standard to ensure accurate and reliable ratings from supplier to supplier. Manufacturers use an upstream concentration of D .0. P. (dioctylphthalate) which is an oil commonly used in the plastics industry. The intent is to produce a high concentration of 0.3 micron particulate matter by heating the D.O.P oil to a temperature of approximately 200 C. This air-stream is then introduced and measured upstream of the HEPA filter to establish an inlet concentration. Measuring downstream of the filters using a photometer, removal efficiencies as high as 99.997% can be seen.
High-Tech industries are extremely familiar with the use of HEPA filters in their clean rooms to ensure that essentially all particulate matter greater than 0.3 microns are eliminated. This is essential, to not interrupt their production facility, cause rejects, and minimize poor quality products as a result of air quality. Other applications that rely on the effectiveness of HEPA filtration include medical, pharmaceutical, films, graphic arts, bio-medical/research and the electronics industry to name a few.
5. CHEMICAL FILTERS
HEPA filters and traditional ventilation filters only remove particulate matter and therefore some other means must be employed to treat and remove gases, odors and vapors. A commonly used and readily available product to achieve this goal is activated carbon.
Activated carbon can come in many shapes, sizes and forms. Traditionally raw substrate materials such as coal, wood, peat-moss and coconut shell are thermally processed to produce an air filter quality activated carbon. A Virgin non-impregnated activated carbon is useful in the removal of general volatile organic compounds (VOC's) or hydrocarbons. It’s uses are widespread, and are frequently applied as a general purpose catch all material for non-critical applications.
For more specific and critical gas phase control, activated carbons can also be impregnated with specialty chemicals. This is done to enhance the removal efficiency and capacity for a specific contaminant that is not effectively captured by the virgin non-impregnated activated carbon. Common impregnates include phosphoric acid, sodium and potassium hydroxide. iodine, potassium permanganate and sulfur to name a few.
It is extremely important to realize that there are thousands of different types of carbons available on the market and the appropriate carbon must be selected for the specific application. That is to say that if you have purchased a “BLACK” carbon it is not necessarily what you need. For the novice, making media selections is often the most difficult aspect of the gas-phase filtration design process. Please feel free to contact us at Quatro and use our in-house chemical engineers to evaluate your needs for your specific application. |