According to Energy.gov, routinely replacing the AC filter on your air conditioner is the most important maintenance task that you can perform to ensure the efficiency of your air conditioner.
That’s because a clogged, dirty filter will block the normal airflow and significantly reduce your system’s efficiency. When normal air flow is obstructed, the air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil’s heat-absorbing capacity. Replacing that dirty, clogged filter with a clean one can lower your air conditioner’s energy consumption by 5% to 15%!
But which air filter do you choose?
If you’ve been to the hardware store lately, you’ve probably noticed how much the air filter aisle has grown over the last few years. Let’s take a closer look at the myriad of choices available to homeowners now and answer 5 of the most common questions we hear from our customers about their AC filters.
What Size AC Filter Do I Need?
It’s important to use the size of filter recommended by the manufacturer of your unit. Using an improperly-sized filter can be just as detrimental to your unit as having a dirty filter! If you’re not sure how to determine what size filter your unit needs, let us know and one of our friendly technicians would be happy to assist you!
Most air filters are 1” in thickness but can range in thickness from 1” to 4”. Thicker filters are preferable to thinner filters because they trap more contaminants and need to be replaced less frequently. Not all AC units are designed to accommodate thicker filters, however, so you should measure the filter area of your unit to make sure it will accommodate a thicker filter before purchasing one.
What Type of AC Filter Do I Need?
Filters are generally categorized by the material they are made of and by their MERV rating.
All filters have a Minimum Efficiency Reporting Value (MERV) rating. MERV stands for Minimum Efficiency Reporting Value. These filters are rated on how small of a particle they can filter out of the air. The numbers range from 1 to 16. The higher the number, the better the filtration.
A low ranking filter is rated 1-4 MERV. A medium filter falls into the 5-13 MERV range. A high-efficiency filter will range from 13 to 16 MERV.
You might think that the filter with the highest MERV rating is automatically the best choice but the same technology that traps small particles in a high-end filter will also reduce airflow which causes your AC unit to work harder. The best filter to choose is one that balances good filtration with good airflow.
Types of Filters
Fiberglass filters are typically the least expensive choice. They have a low MERV rating of 1-4 and trap only the largest particles. Fiberglass filters need to be replaced every 30 days. Many HVAC professionals prefer fiberglass filters because they have minimal impact on unit airflow and overall efficiency.
Pleated filters are more expensive than fiberglass filters but are capable of holding more particle contaminants due to their accordion-like structure. They typically have a mid-level MERV rating of 8-13. With a lifespan of 90 days, pleated filters don’t need to be replaced as often as fiberglass filters. Because they trap more contaminants, they typically reduce unit airflow more than fiberglass filters.
HEPA stands for High-Efficiency Particulate Air filters. They typically range from 17-20 MERV.
HEPA filters meet standards that remove at least 99.97% of airborne particles. Hospitals often use these types of filters to stop the spread of disease-causing organisms.
How Often Should I Change My AC Filter (Really)?
At Gator Air & Energy, we recommend that customers change their AC filter roughly four times per year but this number can vary based on the individual. For instance, if you rarely use your AC, you might be able to go six months without changing your filter. If you have multiple pets or someone in your home has allergies, you might need to change your filter as often as every three weeks. To change the filter, all you have to do is measure the size of the filter (the size is usually written around the edge of the filter), pick up a new filter at your local hardware store, and replace the old with the new. If you need help removing your old filter and installing the new one, give us a call.
How Can I Make it Easier to Remember to Change My Air Filter?
If you’re someone who has trouble remembering to change your filter, you’re not alone.
Many filter manufacturers and retailers (including Amazon) now offer home delivery so you don’t have to make a special trip to the hardware store to buy a new one. You can even sign up for a monthly subscription plan and get a fresh, new AC filter delivered right to your door every few months. At a minimum, you can use daylight savings time (Spring Forward, Fall Back) as a reminder to change your filters once every six months.
When Should I Call a Professional?
As we explained in a previous article, changing your air filter regularly is only half of the problem when it comes to dust, mold, and mildew in your home. A thorough air duct cleaning will also help to improve the air quality in your home and improve your HVAC system’s efficiency.
We hope you found this information helpful! If you have additional questions about home filtration or indoor air quality, contact us and one of our friendly Gator Air & Energy professionals would be happy to help you. We wish you and your family good health all through the year!