Just go to any home improvement store and the choice of home air filters can be dizzying. What’s the best one? Does the price reflect the quality? These are just a couple of the questions that make purchasing air filters for your home mind-boggling. Let Finch Air Conditioning & Heating try to help you de-mystify the air filter dilemma.
Here’s an easy way to tell how efficient your current filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Hold the filter horizontally, then with everyday table salt, begin to pour the salt through the filter to 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 pass through as well. You really should upgrade your filter to higher quality filter that is more efficient.
Size, MERV rating and material – these are the three primary factors used to pick the proper air filter for your home.
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 variety 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 capture contaminants.
To explain MERV ratings more impactfully, 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 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 ensure better filtration efficiency, it is critical to understand that too high a MERV filter may also take more to operate your HVAC 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.
Consider it this way, the most efficient ‘filter’ would equivalent to a piece of plywood that prevents ALL contaminants and all the air from getting into your La Porte home. That's all-out air filtration, but would also be a terrible way to live.
A safe bet for most systems would be a MERV 6-8. A higher MERV filter should be used subject to the advice of your Finch Air Conditioning & Heating technician to verify your system has the capability of moving the correct 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 suffers from allergies or respiratory problems and needs a high MERV 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 ten years. Initially, 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. La Porte area homeowners expect their air filter to save children from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!