You know the gist of how air filters generally work, the air comes through clean and your home stays smelling fresh. But this is not as simple as a point A to point B scenario, the air is actually cleaned down to the particles traveling with it through into system behind the filter. This process prevents all kinds of particles like pathogens, contagions, dust, dirt, sand, mold, bacteria, viruses, allergens or pollutants from coming through. The air filters work constantly from the moment they are installed, raising air quality indoor air quality.
The effectiveness of the filters is actually ranked on an easy to follow a system called the MERV scale. The scale is used to tell you just how effective a filter is by rating its mesh weaving and detailing what kind of particles it is capable of stopping. This is useful to know so that you understand just how capable your air filters are from the moment you install them in. The filters continue to work until they become so dirty you have to replace them, so do not worry about their effectiveness until this point.
Understanding the Point of the Ratings
Air filters in system are made to clean up air as it passes through, making sure that your home smells clean but any particles are trapped or absorbed. This is important to not because the MERV rating will tell you just how tight a filters mesh weaving is, thus showing you what particles are stopped. However, you do not want the mesh weaving to be too tight. Higher MERV rated filters are generally used for industrial purposes because the weaving is often too tight for normal air systems to handle.
You need to know what air filters work best for your home and for that to work you should look into the owners manual for a system. The manual will tell what MERV rating is best and what air filters sizes are needed in order to keep the air coming in smoothly. The general consensus is that more average rated air filters are best for a home air system. When the rating is too low, any number of particles could come through. If the rating is too high, then the system will suffer from several problems that could end up costing you.
The same problems that happen with dirty air filters happen with filters that have a MERV rating that is too high. The airflow is unable to travel through into the system behind it due to the fact that there is not enough space in the mesh weaving to allow travel. First of all, this means that your home will see a dip in fresh air quality since less is getting by. But as the filter continues to block air, you could be facing issues of mechanical damage, since the system will continue to try and push the air forward.