You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. What does my system require? Is the more expensive products worth the investment? These are just a few of the questions that make selecting home air filters so mind-boggling. Let Service Experts Heating & Air Conditioning crack the code of home air filters for you, so you can feel comfortable with your purchase.
Here’s a tried and true way to figure out how efficient your old filter is (NOTE: To avoid a big mess, we highly recommend conducting this test outside or over a protected surface): Hold the filter horizontally, then using common table salt, pour the salt through the filter then see how much comes out the other side. If some or all the salt falls through the filter, then you can imagine that the filter will let dust that same size flow through. You might want to upgrade your filter to something more efficient.
Home air filter selection depends primarily on three factors: Size, material and MERV rating.
1) Filter Size
Purchasing a properly sized air filter for your Raleigh home is important. Simply look at the label of your existing filter to see the dimensions, or just measure it yourself. Typically home air filters are 1” thick, but there are a variety of standard width and height dimensions, and some systems have thicker filters.
2) Material & MERV Rating
The efficiencies of filters are rated on a scale of 16, known as MERV ratings. MERV stands for Minimum Efficiency Reporting Value. This number identifies for the user, under the least efficient conditions, how well the filter is designed to contain contaminants.
To help explain the scale of this system, these are some common MERV ratings and how they relate to efficiencies. This is only a guide, so be sure to read the filter manufacturers’ information when purchasing specific filters.
Rating Average Filtration Efficiency
MERV 1-4 60-80%
Fiberglass, Disposable Panel, Washable metal/synthetic, self-charging (Passive)
MERV 5-8 80-95%
Pleated, Media panel, Cube
MERV 9-12 >95%
Extended pleated
MERV 13-16 >98%
Electronic
Be Careful About High MERV Ratings
While a higher MERV number may ensure better filtration efficiency, it is very important to understand that too high a MERV filter may also cost you more to operate your heating and air conditioning system. The higher the MERV, the less the air may flow through the system, and the harder the system may need to work. Your objective should be to get the right balance between air flow, air filtration level and energy efficiency.
Consider it this way, the most efficient ‘filter’ would probably be a piece of plywood that stops ALL contaminants and all the air from entering your Raleigh home. That's all-out air filtration, but would also be a terrible way to live.
A safe bet for most systems would be a MERV 6-8. A higher MERV filter should be used subject to the advice of your Service Experts Heating & Air Conditioning representative to verify your system has the capability of moving the proper amount of air through higher efficiency filters. You generally do not want to lose energy-efficiency for filter efficiency; you want a balance of the two. However, if your family deals with allergies or respiratory problems and needs a high MERV air filter, consider a whole-home air filtration solution that will achieve your energy and filter efficiency needs.
Filtration has changed greatly over the past several years. In the beginning, home air filters were used in the furnace or air handler only to protect the comfort equipment itself. Today it’s a whole new ballgame. Raleigh area homeowners expect their air filter to save loved ones from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!