Just go to any home improvement store and the choice of home air filters can be dizzying. Which brand is best? Should you just get the cheapest? These are just two of many of the questions that make the selection mind-boggling. Let Pardee Service Experts Heating & Air Conditioning crack the code of home air filters for you, so you can feel comfortable with your purchase.
Here’s an easy way to figure out how efficient your current 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 using common table salt, begin to 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 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
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 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 informs the user, under the least efficient conditions, how well the filter is designed to capture contaminants.
As a basic example, these are some common MERV ratings and how they correspond to efficiencies. This is only a guide, so don’t forget 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 offer better filtration efficiency, it is extremely important to understand that too high a MERV filter may also cost you 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 Charleston home. That's definitely the “best” air filtration, but would also be the least comfortable way to go.
The default choice for most systems would be a MERV 6-8. A higher MERV filter should be used on the advice of your Pardee Service Experts Heating & Air Conditioning technician to confirm your system has the capability of moving the suitable quantity 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 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 greatly over the past few years. Early on, home air filters were used in the furnace or air handler only to safeguard the comfort equipment itself. Today it’s a whole new ballgame. Charleston area homeowners expect their air filter to save kids from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!