Trying to select the right air filter for your Knoxville home can be a daunting experience. What’s the best one? Should you just get the cheapest? These are just a few of the questions that make the selection mind-boggling. Let R & M Climate Control 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 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): Hold the filter horizontally, then using common table salt, begin to 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 know that the filter will let dust pass through as well. You should probably upgrade your filter to higher quality filter that is more efficient.
There are 3 primary considerations when choosing a household air filter; 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. 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 identifies for the user, under the least efficient conditions, how well the filter is designed to capture contaminants.
As a basic example, these are some common 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 require more to operate your heating and air conditioning 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 objective should be to get the right balance between air flow, air filtration level and energy efficiency.
Look at 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 Knoxville home. That's maximum air filtration, but would also be like living in a box.
A safe bet for most systems would be a MERV 6-8. A higher MERV filter should be used based upon the advice of your R & M Climate Control Service Experts Heating & Air Conditioning representative to verify your system has the capability of moving the suitable amount 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 few years. Initially, home air filters were used in the furnace or air handler only to protect the comfort equipment itself. The story is different today. Knoxville 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!