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 purchasing air filters for your home mind-boggling. Let Becht/Givens Service Experts try to help you de-mystify the air filter dilemma.
Here’s an easy way to determine how efficient your old filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Position the filter horizontally, then using common table salt, begin to 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 can imagine that the filter will let dust pass through as well. You might want to upgrade your filter to higher quality filter that is 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 proper measurements, or just measure it yourself. The majority of 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
The efficiencies of filters are rated on a scale of 16, known as MERV ratings. 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 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 extremely important to understand that too high a MERV filter may also cost you more to operate your heating and air conditioning system. The higher the MERV, the less 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 equivalent to a piece of plywood that stops ALL contaminants and all the air from entering your Louisville 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 subject to the advice of your Becht/Givens Service Experts technician to ensure your system has the capability of moving the suitable quantity of air through higher efficiency filters. You normally do not want to lose energy-efficiency for filter efficiency; you want a balance of the two. However, if your family deals with allergies or respiratory problems and a high MERV rated filter is required, consider a whole-home air filtration solution that will meet your energy and filter efficiency needs.
Filtration has changed greatly over the past several 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. Louisville area homeowners expect their air filter to save loved ones from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!