Many people do not realize just how many options they have when choosing a filter for their air conditioner. While you may have grown accustomed to just grabbing whichever type is the cheapest at the hardware store, it’s important to recognize that not all filters are created equal. Some are far more efficient than others. And if you’re interested in improving the efficiency of your air conditioning system to both lower your energy bills and keep the air in your home clean and safe to breathe, you’ll want to choose a filter with a high efficiency rating.
Here, we’ll tell you more about how filters are ranked by efficiency and help you discover the perfect filter type for your home.
What Is MERV Rating?
MERV stands for Minimum Efficiency Reporting Value. This scale, ranging from 1 to 20, is how air filters are ranked for their efficiency: the higher the MERV rating, the more effective the filter. This means fewer airborne particles, some of which can be harmful to our health, are allowed to pass through it. However, it is important to note that the most efficient filter is not necessarily the best, as filters with the highest MERV rating may actually impede airflow.
Air Filters Ranked by Efficiency
Here’s a look at some of the most common types of disposable air filters and how they measure up.
Fiberglass: MERV 1-4
While you can find fiberglass filters for just couple of bucks, these filters do little to protect your indoor air quality. A fiberglass filter will typically remove only about 10 percent of the pollen, dust mites, mold spores, pet dander and other particles that circulate through your air.
Electrostatic: MERV: 10
Electrostatic air filters contain self-charging cotton or paper fibers that attract particles in the air and trap them. As most air conditioners can effectively remove harmful particles with a filter rated MERV 7 or above, an electrostatic filter is a great choice for those with pets or who are prone to allergies. One downside, however, is that these filters can become expensive when custom sizing is necessary.
Pleated: MERV 10-13
Made from cotton or polyester, pleated filters are one the most popular and efficient filter choices. Their effectiveness, however, varies upon pleats per foot. For a pleated filter to have an efficiency rating of 10 to 13, it should have at least 18 pleats per foot. These filters will need to be changed frequently, but since they can be purchased for less than $5 a piece, they are still an affordable option.
High-efficiency Pleated: MERV: 14-16
These filters are a step up from regular pleated filters, as they are 4 to 5 inches thick. Made of synthetic cotton, these filters will do a great job of filtering even the smallest particles, but can typically only be installed in special units, due to their thickness. While these filters will not have to be changed out as frequently, they can be pricey for the average homeowner.
HEPA (High Efficiency Particulate Air): MERVE 17-20
While a HEPA filter is 98 percent effective at removing pollutants from the air, it is not practical for use in most homes. Because these filters restrict airflow, they can only be used in a whole-home filtration system or a separate, standalone air purifier.