You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. What’s the best one? Does the price reflect the quality? These are just some of the questions that make selecting home air filters so 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 tell 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 taking everyday table salt, pour the salt through the filter then 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 pass through as well. You should probably upgrade your filter to an air filter that’s 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 height by width and thickness, or just measure it yourself. Typically 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
MERV ratings are the efficiencies of the filter on a scale of 16. MERV stands for Minimum Efficiency Reporting Value. This number tells the user, under the least efficient conditions, how well the filter is designed to contain contaminants.
To explain MERV ratings more impactfully, 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 purchasing 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 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.
Look at 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 getting into your Livermore home. That's all-out 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 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 deals with allergies or respiratory problems and the situation necessitates a high MERV rated air filter, consider a whole-home air filtration solution that will meet your energy and filter efficiency needs.
Filtration has changed significantly over the past several years. Originally, home air filters were used in the furnace or air handler only to shelter the comfort equipment itself. Today it’s a whole new ballgame. Livermore 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!