Just go to any home improvement store and the choice of home air filters can be dizzying. What does my system require? Is the more expensive products worth the investment? These are just a few of the questions that make the selection mind-boggling. Let Freschi Service Experts try to help you de-mystify the air filter dilemma.
Here’s a tried and true way to figure out how efficient your old 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, pour the salt through the filter and see how much 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 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
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. Most 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 informs the user, under the least efficient conditions, how well the filter is designed to hold 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 make sure you read the filter manufacturers’ information when buying 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 provide better filtration efficiency, it is very important to understand that too high a MERV filter may also require more to operate your HVAC 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 objective should be 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 prevents ALL contaminants and all the air from entering your Concord home. That's definitely the “best” 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 Freschi Service Experts service advisor to ensure your system has the capability of moving the correct volume 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 suffers from 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 few years. Early on, home air filters were used in the furnace or air handler only to safeguard the comfort equipment itself. But (in the words of Bob Dylan) the times they are a changing. Concord area homeowners expect their air filter to save children from a wide variety of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!