Just go to any home improvement store and the choice of home air filters can be dizzying. What does my system require? Is the more expensive products worth the investment? These are just some of the questions that make purchasing air filters for your home mind-boggling. Let Service Experts Heating & Air Conditioning try to help you de-mystify the air filter dilemma.
Here’s a tried and true way to figure out 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): Hold the filter horizontally, then taking common table salt, pour the salt through the filter and see the amount comes out the other side. If some or all the salt falls through the filter, then you can assume that the filter will let dust particles of similar size pass through. You really should 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
Size is the easiest factor to ascertain. Simply look at the label of your existing filter to see the dimensions, 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
Filter efficiencies are given a number from 1-16 called the MERV rating. MERV stands for Minimum Efficiency Reporting Value. This number informs the user, under the least efficient conditions, how well the filter is designed to hold contaminants.
As a basic example, these are some usual MERV ratings and how they relate to efficiencies. This is only a guide, so make sure you 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 offer better filtration efficiency, it is very important to understand that too high a MERV filter may also require more to operate your heating and air conditioning 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 goal 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 actually be a piece of plywood that would just trap ALL contaminants and all the air from entering your Fort Myers home. That's definitely the “best” air filtration, but would also be a terrible way to live.
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 technician to ensure your system has the capability of moving the proper volume of air through higher efficiency filters. You probably 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 needs a high MERV air filter, consider a whole-home air filtration solution that will satisfy your energy and filter efficiency needs.
Filtration has changed greatly over the past ten years. Originally, home air filters were used in the furnace or air handler only to shelter the comfort equipment itself. But (in the words of Bob Dylan) the times they are a changing. Fort Myers area homeowners expect their air filter to save children from a wide variety of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!