Trying to select the right air filter for your Hillsborough home can be a daunting experience. Which brand is best? Should you just get the cheapest? These are just a couple of the questions that make the selection mind-boggling. Let Fras-Air/General Service Experts Heating & Air Conditioning try to help you de-mystify the air filter dilemma.
Here’s a simple way to determine how efficient your current filter is (NOTE: Spare yourself a huge mess by conducting this experiment outside or with something below the filter to help keep things clear): Position the filter horizontally, then with everyday table salt, pour the salt through the filter then see the quantity that comes out the other side. If some or all the salt falls through the filter, then you know that the filter will let dust particles of similar size pass through. You might want to upgrade your filter to something more efficient.
There are 3 primary considerations when choosing a household air filter; Size, Material and MERV rating.
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. Typically 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 contain contaminants.
As a basic example, these are some common MERV ratings and how they correspond 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 offer 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 difficult 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 would just trap ALL contaminants and all the air from entering your Hillsborough home. That's maximum 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 Fras-Air/General Service Experts Heating & Air Conditioning technician to verify your system has the capability of moving the proper volume of air through higher efficiency filters. You normally do not want to give up energy-efficiency for filter efficiency; you want a balance of the two. However, if your family has 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 considerably over the past several years. Originally, 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. Hillsborough area homeowners expect their air filter to save kids from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!