Have you ever gone to a store to pick up a new filter for your furnace and just stared at the aisle unsure which one you should get? When choosing the right filter for your furnace there are a couple things you should keep in mind. Your filter size, the MERV rating and filter type. Making sure your filter is the correct size is important because putting a filter that is either too big or too small could cause damage to your furnace. MERV stands for “Minimum Efficiency Reporting Value”. The higher the MERV rating, the less particulates are getting into your home. Here are the most common types of filters that are used in a home and the pros and cons of each.
Fiberglass filters are the most common furnace filters as they are most economical and can be found in almost any store that carries home supplies. They are created from spun fiberglass and usually only one inch thick. They will provide maximum airflow. However, they have a low rating of MERV 4 meaning that it will only filter 20% of the particulates that pass through it. Fiberglass filters will need to be checked on a monthly basis as they are more prone to getting clogged due to their construction. They will protect your furnace from large objects/debris damaging mechanical components. However, they do not help if you have concerns about allergens or mold spores in your home.
Pleated filters are made of cotton-polyester with a cardboard frame. They come in an array of sizes ranging from 1-5 inches thick. The pleats (waves) increase the surface area which results in better filtration as it can take in more air. These filters are great for homeowners looking to filter dust mites, mold spores and other fine particles as they have a MERV 8 rating meaning that it will filter 30-35% of all particulates that pass through it. Since pleated filters are very fine, they will slightly decrease airflow, but not enough to be noticeable for the common homeowner. Although more expensive than fiberglass filters they will only need to be changed on a 3 to 4-month basis as the filter itself has a larger surface area than that of a fiberglass. Pleated filters are what Modern PURAIR® recommends for homeowners looking to protect themselves from common allergens and to help their homes Indoor Air Quality. However, if you are looking to protect your home from bacteria, exhaust fumes, carbon emissions than this is not the best option for you.
Electrostatic filters can be found in disposable and permanent form. At Modern PURAIR® we recommend the “Dynamic Polarized Media Electronic Air Cleaner” as it’s housing is permanent and will only require yearly media pad changes. Although the Dynamic Filter has a larger initial investment, it requires substantially less maintenance than both the fiber glass and pleated filters. This filtration system has a MERV 20 rating meaning it will filter 97 % of all particulates passing though. If you are looking to protect your home from not only dust, mold spores and common allergens, but also all bacteria, combustion smoke and viruses. Or, if the indoor air quality in your home is a concern to you than this the best option for you. It is the same MERV rating that is used in hospital operation rooms so you can be sure that it can handle almost anything found in the common residential home.
So before you go and purchase your next furnace filter think about what expectation you have for it and it will help make your decision much easier.