You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. What’s the best one? Is the more expensive products worth the investment? These are just some of the questions that make selecting home air filters so mind-boggling. Let Service Experts Heating & Air Conditioning try to help you de-mystify the air filter dilemma.
Here’s a simple way to tell how efficient your old filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Position the filter horizontally, then taking standard table salt, begin to pour the salt through the filter then see the quantity that 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 might want to upgrade your filter to higher quality filter that is more efficient.
There are 3 primary considerations when choosing a household air filter; Size, Material and MERV rating.
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. Most home air filters are 1” thick, but there are a numerous 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 capture contaminants.
To explain MERV ratings more impactfully, these are some usual MERV ratings and how they correspond 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 ensure better filtration efficiency, it is extremely important to understand that too high a MERV filter may also take more to operate your furnace and AC system. The higher the MERV, the more difficult 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.
Think about it this way, the most efficient ‘filter’ would equivalent to a piece of plywood that prevents ALL contaminants and all the air from getting into your Miami home. That's all-out air filtration, but would also be like living in a box.
A safe bet for most systems would be a MERV 6-8. A higher MERV filter should be used on the advice of your Service Experts Heating & Air Conditioning service advisor to confirm your system has the capability of moving the correct amount of air through higher efficiency filters. You normally do not want to give up energy-efficiency for filter efficiency; you want a balance of the two. However, if your family has allergies or respiratory problems and a high MERV rated filter is required, consider a whole-home air filtration solution that will achieve your energy and filter efficiency needs.
Filtration has changed greatly over the past few years. Initially, home air filters were used in the furnace or air handler only to shelter the comfort equipment itself. The story is different today. Miami area homeowners expect their air filter to save loved ones from a wide variety of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!