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? Should you just get the cheapest? These are just a couple of the questions that make selecting home air filters so mind-boggling. Let Midway Services try to help you de-mystify the air filter dilemma.
Here’s a simple way to determine 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 with everyday table salt, pour the salt through the filter to see the quantity that 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 particles of similar size pass through. You really should upgrade your filter to higher quality filter that is 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 height by width and thickness, or just measure it yourself. Most 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
Filter efficiencies are given a number from 1-16 called the MERV rating. 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 capture contaminants.
As a basic example, these are some typical 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 critical 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 entering your Clearwater home. That's definitely the “best” 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 on the advice of your Midway Services technician to verify your system has the capability of moving the proper volume of air through higher efficiency filters. You generally do not want to sacrifice 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 achieve your energy and filter efficiency needs.
Filtration has changed significantly over the past ten 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. Clearwater area homeowners expect their air filter to save kids from a wide variety of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!