How to Choose Between Different Types of Air Filters

All HVAC systems come with a built-in air filter. These are designed to help trap airborne pollutants to not only improve your indoor air quality but also keep these pollutants from entering the internal components of your system. We’re going to discuss the different types of air filters that are available for your system so that you can choose the best one to meet your needs.

The 3 Basic Filter Options

In general, there are three main types of HVAC air filters that you can purchase. These include fiberglass, pleated, and washable filters. Each filter comes with its own benefits and drawbacks that you need to be aware of.

Fiberglass

Fiberglass filters are the cheapest to purchase. They’re ideal for collecting large particles like pet dander from your air. Fiberglass filters come with a cardboard frame that houses a single, flat filter. These filters tend to have a low minimum efficiency reporting value (MERV) rating of 2 to 4. 

Pleated

Pleated air filters come at a slightly higher cost and can trap smaller particles. Some of these include lint, pollen, and dust mites. Unlike flat fiberglass filters, these have a pleated filter fabric that provides more surface area to catch debris. Pleated filters have MERV ratings of 5 and above.

Washable

Lastly, we have the washable filter that is specifically designed to be reusable. This type of filter will have a MERV rating between 1 and 4. Much like the fiberglass filter, it can trap larger airborne particles. These filters can last up to five years, with proper maintenance. 

A Note on MERV Ratings

Simply put, a MERV rating measures how efficiently your filter will stop dust and other airborne contaminants. The MERV scale runs from 1 all the way up to 20. Generally speaking, air filters with a MERV rating between 17 and 20 are not compatible with most residential HVAC systems. Rather, they’re designed to be used with commercial-grade units.

Below is a list of MERV ratings and their filtering capabilities. All ratings include the items listed next to them, as well as all the items listed for filters with a MERV rating below them. 

• MERV 1 to 4: dust, carpet fibers, and pollen
• MERV 5 to 8: mold spores, animal dander, hair spray
• MERV 9 to 12: bacteria and lead dust
• MERV 13 to 16: tobacco smoke, viruses, and other pathogens

In general, the higher MERV rating a filter has, the more expensive it will be. Following this logic, fiberglass filters with a MERV rating of 4 will be much cheaper than pleated filters with a rating of 12. However, the 12-rated pleated filters are going to remove many more airborne pollutants, especially smaller ones, than the fiberglass 4-rated filter.

Pet Owners and Medical Conditions

When deciding on the perfect air filter for your home, it’s important to take into account any unique features that may affect your home more than the average household. One of these factors is pets. The more pets you have indoors, the more pet dander and debris will be introduced into your air. For this reason, you’ll want to consider getting a filter with a higher MERV rating. Most experts recommend one with a rating around 11. 

If you or another member of your household suffers from asthma, allergies, or a respiratory condition, then you’ll need a higher-rated filter. This way, you can trap more airborne allergens that would otherwise lead to symptom flare-ups. A good filter to trap finer airborne pollutants is MERV 13.

Locating Your Air Filter

One of the best places to start when determining the ideal filter for your home is to check the rating on your existing filter. Your air filter is located in a housing inside the return ducting near your heating or cooling system. There should be a lid you can pop off to allow you direct access to the filter. You’ll want to turn your HVAC system off at the thermostat. Then, pull out your existing filter, and check its MERV rating and size. 

It’s important to note that all filters must be installed in the appropriate direction. Your filter should have an arrow on the side of its frame. Additionally, the direction of airflow should be marked on your ducting. If not, it flows from the vents and into your heating system. When installing your new filter, be sure the arrow on the filter matches the appropriate direction of airflow throughout your HVAC system. Installing your filter backward could result in inefficient airflow and even system failure.

Filter Sizing

All HVAC filters will be given a size that designates its length, height, and depth, such as 16x20x1. All sizes are rounded up to be nominal numbers. For example, if your filter depth is 0.75 of an inch, its size marking will be rounded up to the nominal 1 inch. 

It’s important to replace your existing air filter with one of a similar size. If you get a filter that’s too big, it won’t fit in the filter housing. If you get a size that’s too small, air will be pulled around the filter and enter your HVAC system unfiltered. 

Maintenance Requirements

All air filters have a finite lifespan, usually around two to three months. It’s advisable to pull out your air filter every month. Hold it up to a light source and see if you can adequately see through it. If so, it’s still good. If not, it needs to be replaced with a new one. You should have at least one spare filter on hand to replace a worn-out one without delay. 

The frequency of filter replacements depends highly on numerous factors specific to your household. These include the filter’s rating, how many pets you have, how often you have guests, your cleaning habits, and so forth. You may even notice that you need to change filters more often during the winter and summer seasons, as your family spends more time indoors. 

When it comes to washable filters, you can save money by not having to fully replace the filter when it gets dirty. However, you must take appropriate care when washing these filters to ensure their longevity and the overall health of your HVAC system. Make sure that you shut off your HVAC system completely before removing the washable filter. Using a gentle dish soap alongside warm water and a soft-bristle brush, you can easily scrub any grime and debris off the air filter. Make sure you let the filter dry out completely before reinstalling it. Running it wet can allow for unwanted mold and mildew growth. 

Expert IAQ Services

Revival Energy Group offers expert indoor air quality services for Vancouver, WA and the surrounding areas. We can also help with all your air conditioning, heating, ductless mini-split, oil to gas conversion, air sealing, window, insulation, and ductwork improvement needs. 

Give us a call today to schedule your next service appointment!