You’ve probably experienced the feeling of confusion when trying to select the correct home air filter for your needs. What does my system require? Is the more expensive products worth the investment? These are just some of the questions that make purchasing air filters for your home mind-boggling. Let A1 Chesney Service Experts Heating & Air Conditioning try to help you de-mystify the air filter dilemma.
Here’s an easy way to determine how efficient your old filter is (NOTE: To avoid a big mess, we highly recommend conducting this test outside or over a protected surface): Position the filter horizontally, then taking common 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 particles of similar size pass through. You might want to upgrade your filter to an air filter that’s 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
Purchasing a properly sized air filter for your Calgary home is important. 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
The efficiencies of filters are rated on a scale of 16, known as MERV ratings. 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.
To explain MERV ratings more impactfully, these are some common MERV ratings and how they relate to efficiencies. This is only a guide, so make sure you read the filter manufacturers’ information when shopping for 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 extremely important to understand that too high a MERV filter may also take 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.
Consider it this way, the most efficient ‘filter’ would equivalent to a piece of plywood that stops ALL contaminants and all the air from entering your Calgary home. That's definitely the “best” 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 A1 Chesney Service Experts Heating & Air Conditioning service advisor to ensure your system has the capability of moving the suitable amount of air through higher efficiency filters. You normally do not want to give up energy-efficiency for filter efficiency; you want a balance of the two. However, if your family has allergies or respiratory problems and needs a high MERV air filter, consider a whole-home air filtration solution that will satisfy your energy and filter efficiency needs.
Filtration has changed considerably over the past ten years. In the beginning, 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. Calgary area homeowners expect their air filter to save loved ones from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!