You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. Which brand is best? Should you just get the cheapest? These are just two of many of the questions that make the selection mind-boggling. Let BW/Cook Service Experts Heating & Air Conditioning attempt to resolve your home air filter questions and allow you to continue enjoying the comfort of your home without concern.
Here’s an easy way to figure out 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): Hold the filter horizontally, then using standard table salt, start pouring the salt through the filter and see the amount comes out the other side. If some or all the salt falls through the filter, then you know that the filter will let dust that same size flow through. You really should upgrade your filter to something 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
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 height by width and thickness, or just measure it yourself. Typically home air filters are 1” thick, but there are a number 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 tells the user, under the least efficient conditions, how well the filter is designed to contain contaminants.
To help explain the scale of this system, these are some typical 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 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.
Consider it this way, the most efficient ‘filter’ would probably be a piece of plywood that prevents ALL contaminants and all the air from getting into your Elkhart home. That's all-out air filtration, but would also be the least comfortable way to go.
Your best bet for most systems would be a MERV 6-8. A higher MERV filter should be used subject to the advice of your BW/Cook Service Experts Heating & Air Conditioning technician to ensure your system has the capability of moving the suitable volume of air through higher efficiency filters. You probably do not want to lose energy-efficiency for filter efficiency; you want a balance of the two. However, if your family has allergies or respiratory problems and a high MERV rated filter is required, consider a whole-home air filtration solution that will satisfy 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 shelter the comfort equipment itself. But (in the words of Bob Dylan) the times they are a changing. Elkhart area homeowners expect their air filter to save kids from a wide variety of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!