You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. Which brand is best? Is the more expensive products worth the investment? These are just a few 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 an easy way to tell how efficient your existing filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Set the filter horizontally, then taking standard table salt, begin to pour the salt through the filter to see the quantity that 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 that same size flow through. You should probably upgrade your filter to an air filter that’s more efficient.
Home air filter selection depends primarily on three factors: Size, material and MERV rating.
1) Filter Size
Unless you have the proper size home air filter, you will never enjoy the full effectiveness your system and filter can provide. Simply look at the label of your existing filter to see the dimensions, or just measure it yourself. The majority of home air filters are 1” thick, but there are a variety of 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 identifies for the user, under the least efficient conditions, how well the filter is designed to contain contaminants.
As a basic example, these are some usual MERV ratings and how they correspond to efficiencies. This is only a guide, so don’t forget 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 offer better filtration efficiency, it is critical to understand that too high a MERV filter may also require more to operate your HVAC system. The higher the MERV, the less the air may flow through the system, and the harder the system may need to work. Your objective should be to get the right balance between air flow, air filtration level and energy efficiency.
Consider it this way, the most efficient ‘filter’ would actually be a piece of plywood that prevents ALL contaminants and all the air from entering your Denver home. That's all-out air filtration, but would also be a terrible way to live.
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 Service Experts Heating & Air Conditioning technician to confirm your system has the capability of moving the proper volume 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 deals with allergies or respiratory problems and needs a high MERV air filter, consider a whole-home air filtration solution that will achieve your energy and filter efficiency needs.
Filtration has changed greatly over the past few 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. Denver area homeowners expect their air filter to save children from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!