How Do I Choose the Best Home Air Filters?
There are 3 factors that you should use to choose the best air filter for your home: the size of the filter, the filter’s MERV rating, and the type of filter. If even one of these is ill-matched to your home’s HVAC system, it will result in poor air quality, a higher heating or cooling bill, and damage to the unit.
Why Does Size Matter For Home Air Filters?
Imagine if you went to buy new work clothes, grabbed something that was a few sizes too small, and tried to show up to work in it. The situation would be very uncomfortable for you and your boss probably wouldn’t take it too well. Size matters is everything from clothing to air filters. The same principle applies when you replace your home air filter. If the filter is too big, it will not fit properly into the unit. If it is too small, it will not effectively filter the air inside your home.
The best way to buy the right size air filter is to simply look at your previous filter. The old filter should be marked with the dimensions and the thickness. All you need to do is jot down these measurements and look for a similar product at your nearest home improvement store. It may help to take the old filter with you, or take a photo of it, to ensure that you are buying the correct product.
What is MERV Rating For Home Air Filters?
MERV stands for Minimum Efficiency Reporting Value. This is the number that identifies how well an air filter will work under the least ideal conditions. The MERV rating reflects how effectively a home air filter will prevent dust and particles from getting into your home.
While the MERV rating system goes from 1 all the way up to 16, this does not mean that a higher rating is inherently better. Air filters work best when they are matched to the needs and design of the HVAC unit. If an air filter is poorly matched, then it will not be as effective. This is the case for older units; a filter with a higher MERV score may be more effective generally, but using it in an older unit may damage the unit.
Filters made from synthetic mesh, fiberglass, washable metal, and disposable filters usually have a MERV score in the 1 to 4 range. This means that they have over 80% efficiency under the least ideal conditions.
Traditional pleated, cube-shaped, and densely pleated air filters normally have a 5 to 8 MERV score. This gives them 80% to 95% efficiency.
Home air filters rated in the 9 to 12 range have over 95% effectiveness. The only type of filter in this category is an extended pleated filter.
The home air filter with the highest MERV rating is electronic filters, which are in the 13 to 16 range and are over 98% effective.
In general, most HVAC units should have an air filter that is rated between MERV 6 and 8.
What Are the Different Types of Home Air Filters?
The MERV scale addresses several types of home air filters. For most HVAC units, the MERV score and size matters more than the material of the filter. However, some homeowners have a preference for one type of filter over another.
- Flat-Panel Air Filters: These are affordable and disposable; they are made from fiberglass that is set into a frame. While they are easy to replace, they are not the best quality.
- Pleated Air Filters: Pleated filters look a lot like flat-panel filters, but the key difference is the folds in the material. Disposable pleated filters are normally made from plastic or cotton fiber that is set into a frame. They are more effective than flat filters, but cost a little more.
- Electrostatic Air Filters: The appeal of electrostatic filters is that they are charged in order to more effectively catch particles. This type of filter comes in both disposable and reusable options, as well as pleated and flat designs.
- Washable Air Filters: This type of filter also comes in both flat and pleated designs. The key difference is that this type of filter can be taken outside, washed down, and replaced. Many homeowners love washable filters because they save money long term and are better for the environment.
- HEPA Air Filters: HEPA stands for “High-Efficiency Particulate Air” because it describes any kind of filter that removes at least 99.97% particles. Most residential HVAC systems are unable to handle HEPA filters because they are most often used in commercial settings, such as hospitals and labs.
How Often Do You Have to Change Home Air Filters?
How often you will have to change home air filters depends on how much use the home gets. For vacation homes and residences that are not occupied year round, it is safe to only change the air filters every 9 to 12 months.
For most homes, the frequency for changing the air filter will depend on:
- The number of people who live full-time in the home.
- The number of pets that have air.
- The season.
- The concentration of allergens in the air.
- If anyone in the home has seasonal allergies or is allergic to any local plants.
- How many children are in the home.
- If anyone with a respiratory condition lives in the home.
- The type of air filter you use.
If you have multiple pets with fur, children, or live with more than 3 other people, it is recommended that you change the air filters every 2 months. This will limit the amount of pet hair in the air and keep everyone healthy.
If you or someone you live with experiences allergies, it will be necessary to change the air filters more often. It will also depend on the season and if you live near fields, cottonwood trees, or any kind of factory. If this is the case, the home air filters will need to be replaced every 50 days for the duration of the allergy season. Once winter comes and there are fewer allergens in the air, it will be safe to go down to a 60 day replacement cycle.
The final factor that determines how often you need to replace your air filter is the type of filter. The lower the MERV rating, the more often the filter will need to be replaced. Most disposable flat-panel filters should be replaced every 30 to 50 days for optimal air quality. Pleated air filters can be changed out slightly less often.
Any air filter with a MERV rating over 8 only needs to be changed out every few months. The exact timeline will depend on the individual filter. The best way to learn about your air filter’s timeline is to look at the packaging or visit the manufacturer’s website.
Why Are Home Air Filters Important?
Home air filters are important because they trap dust, pollen, pollution, pet fur, and dirt that would otherwise be swirling around your home. Most people spend upwards of 90% of their time indoors, so the quality of inside air is very important to health.
Air filters are also vital to the functionality and longevity of HVAC units. A good air filter will be thick enough to effectively catch particles, but will not be too thick as to damage the unit. If you place the wrong thickness of air filter into your HVAC system, it could drive up energy bills because the unit has to work harder.
Over time, not having an adequate home air filter can contribute to respiratory diseases and worsen conditions such as asthma and allergies.