If you don't change the AC filter, it will start to fail. You will no longer be able to filter the air properly, allowing dust and contaminants to enter the air conditioner. Dust clogs moving parts of an air conditioner, such as motors and fan valves. Airflow is restricted, creating a strain on the system.
If the air filter is clogged and can't trap contaminants like it used to, those things can go back to the air that everyone in your home breathes. Immediate problems may include headaches, itchy eyes or throat, and dizziness. If the air filters are not changed and problems persist, the long-term effects could be respiratory disease, heart disease, or cancer. Getting the most value out of your home can be as easy as changing air filters.
Homeowners who ignore filters in their heating and air conditioning systems risk increasing energy costs, damaging expensive equipment, and decreasing indoor air quality and personal health. See below to learn what can happen if you don't change your air filters. In general, filters with a MERV 16 rating or lower are considered HVAC system grade filters for residential, commercial, and general hospital use. I remember that once I inspected a house where there were several filters on the roof, and the owners who worked for a foreign embassy had no idea about the maintenance of the house, it seems that they never changed the filters.
But why is this? How can something as simple as changing an air filter be so important? The truth is that not changing your air filter on a regular basis can cause a number of problems with your HVAC system, which we will discuss below. If I see that the filter is not as clean as when I bought it, it's time to change it. The only type of filters that trap allergens and spores are HEPA, or high-energy particulate air filters. Most of us have one-inch pleated filters that change in the return air filter grille on the ceiling or further down the wall if their ducts are under the house.
Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings. The Minimum Efficiency Report Value (MERV) rating for an air filter measures how effectively the filter prevents dust and other contaminants from passing through the filter into the air stream. If you buy filters in-store, they usually come in white with pleats or ridges to help increase the filter surface area. When air filters are not constantly changed, they become clogged by the accumulation of particles and contaminants that adhere to the filter.
Air filters typically have a MERV (Minimum Efficiency Report Value) that determines the type and size of contaminants against which the filter will act. If you haven't changed your home's air filters lately, the next step should be to determine which filters you need and replace them as soon as possible. In general, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days or 3 months. And often, I notice that HVAC filters aren't even properly installed with missing filter caps and slots.
Sometimes I see filters half bent in the center or other signs of having a low air seal around the filter frame.