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 a couple of the questions that make selecting home air filters so mind-boggling. Let Levy & Son Service Experts try to help you de-mystify the air filter dilemma.
Here’s a tried and true way to tell how efficient your existing filter is (NOTE: Spare yourself a huge mess by conducting this experiment outside or with something below the filter to help keep things clear): Set the filter horizontally, then using standard 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 particles of similar size pass through. You might want to upgrade your filter to an air filter that’s 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. 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
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 hold contaminants.
As a basic example, these are some typical MERV ratings and how they connect to efficiencies. This is only a guide, so be sure to read the filter manufacturers’ information when shopping for 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.
Think about 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 coming inside your Dallas 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 subject to the advice of your Levy & Son Service Experts technician to ensure your system has the capability of moving the correct amount of air through higher efficiency filters. You generally do not want to give up 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 satisfy your energy and filter efficiency needs.
Filtration has changed significantly over the past few years. In the beginning, home air filters were used in the furnace or air handler only to safeguard the comfort equipment itself. But (in the words of Bob Dylan) the times they are a changing. Dallas area homeowners expect their air filter to save children from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!