Air Filtration

Most generally, air filters clean the air of particles which enhances the air quality which we breathe. Several different methods are used ranging from electrostatic filters to the simple pad filter or styrofoam. The higher the efficiency number the more filtration is being done.

In the case of operating room quality filters they too are available, but have a much higher price tag and in some cases tighter installation requirements to achieve the high filtration percentage.

Most home owners use the fiberglass disposable filter which is about a 5-7% efficiency. In essence it will get the big chunks, but the smaller particles flow right through and get stuck on the wet surface of the evaporator coil or moisture laden leaving air surfaces, blower, and ductwork. This can cause a vast and sometimes costly remediation issues. The filter above is this type of filter.

A better filter is the pleated filter because of the pleating configuration increases the actual filter surface area and therefore reduces the fpm (feet per minute) or velocity of the air. This enables the filter to be from 25-35% efficient and of course will pick up much more particles in a shorter period of time. Some material will still get through, but it is well worth the difference in price. Generally, this filter shown above is about twice the cost of the spun fiberglass flat filter.

A general conception is that any filter is better than no filter, and this is true, but the higher the efficiency the less the maintenance cost of coil and duct cleanliness will be required. Microbial growth is a totally different issue and is examined completely aside of the filtration function.