Bringing clarity to home air filtration confusion Published on February 06, 2015 Trying to select the right air filter for your Salt Lake City home can be a daunting experience. Which brand is best? Should you just get the cheapest? These are just a couple of the questions that make purchasing air filters for your home mind-boggling. Let Mountainwest 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 a tried and true way to tell how efficient your existing filter is (NOTE: To avoid a big mess, we highly recommend conducting this test outside or over a protected surface): Set the filter horizontally, then with standard table salt, start pouring 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 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 proper measurements, or just measure it yourself. Most 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 identifies for the user, under the least efficient conditions, how well the filter is designed to hold contaminants. To help explain the scale of this system, 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 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% Extended pleated MERV 13-16 >98% Electronic Be Careful About High MERV Ratings While a higher MERV number may ensure 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 aim is to get the right balance between air flow, air filtration level and energy efficiency. Look at 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 Salt Lake City home. That's all-out air filtration, but would also be the least comfortable way to go. 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 Mountainwest Service Experts Heating & Air Conditioning technician to ensure your system has the capability of moving the proper quantity 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 satisfy your energy and filter efficiency needs. Filtration has changed considerably over the past few years. Originally, home air filters were used in the furnace or air handler only to protect the comfort equipment itself. But (in the words of Bob Dylan) the times they are a changing. Salt Lake City area homeowners expect their air filter to save loved ones from a a growing list of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!