Just go to any home improvement store and the choice of home air filters can be dizzying. Which brand is best? Does the price reflect the quality? These are just two of many 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 determine how efficient your existing filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Hold the filter horizontally, then taking common table salt, begin to pour the salt through the filter to see the amount comes out the other side. If some or all the salt falls through the filter, then you know that the filter will let dust particles of similar size pass through. You really should upgrade your filter to something more efficient.
Size, MERV rating and material – these are the three primary factors used to pick the proper air filter for your home.
1) Filter Size
Size is the easiest factor to ascertain. Simply look at the label of your existing filter to see the proper measurements, or just measure it yourself. The majority of home air filters are 1” thick, but there are a number 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 informs the user, under the least efficient conditions, how well the filter is designed to trap contaminants.
To explain MERV ratings more impactfully, these are some typical MERV ratings and how they relate to efficiencies. This is only a guide, so make sure you 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%
MERV 13-16 >98%
Be Careful About High MERV Ratings
While a higher MERV number may offer better filtration efficiency, it is very important to understand that too high a MERV filter may also require more to operate your furnace and AC system. The higher the MERV, the more restricted the air may flow through the system, and the harder the system may need to work. Your aim is to get the right balance between air flow, air filtration level and energy efficiency.
Look at it this way, the most efficient ‘filter’ would actually be a piece of plywood that stops ALL contaminants and all the air from getting into your Memphis home. That's all-out air filtration, but would also be like living in a box.
Your best 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 technician 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 suffers from allergies or respiratory problems and a high MERV rated filter is required, consider a whole-home air filtration solution that will meet your energy and filter efficiency needs.
Filtration has changed significantly over the past ten years. Originally, home air filters were used in the furnace or air handler only to shelter the comfort equipment itself. The story is different today. Memphis area homeowners expect their air filter to save kids from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!