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 a couple of the questions that make selecting home air filters so mind-boggling. Let Midland Air Service Experts try to help you de-mystify the air filter dilemma.
Here’s a tried and true way to determine how efficient your existing filter is (NOTE: To avoid a big mess, we highly recommend conducting this test outside or over a protected surface): Set the filter horizontally, then with everyday 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 pass through as well. You should probably 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
Unless you have the proper size home air filter, you will never enjoy the full effectiveness your system and filter can provide. Simply look at the label of your existing filter to see the height by width and thickness, 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 tells the user, under the least efficient conditions, how well the filter is designed to hold contaminants.
To help explain the scale of this system, these are some usual 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%
MERV 13-16 >98%
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 take more to operate your HVAC 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 goal is 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 would just trap ALL contaminants and all the air from getting into your Columbia home. That's maximum air filtration, but would also be a terrible way to live.
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 Midland Air Service Experts technician to confirm your system has the capability of moving the correct 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 has allergies or respiratory problems and the situation necessitates a high MERV rated air filter, consider a whole-home air filtration solution that will meet your energy and filter efficiency needs.
Filtration has changed considerably over the past several years. Early on, home air filters were used in the furnace or air handler only to shelter the comfort equipment itself. The story is different today. Columbia area homeowners expect their air filter to save children from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!