Bringing clarity to home air filtration confusion

Trying to select the right air filter for your Austin home can be a daunting experience. Which brand is best? Is the more expensive products worth the investment? These are just a couple of the questions that make selecting home air filters so mind-boggling. Let Strand Brothers Service Experts Heating & Air Conditioning try to help you de-mystify the air filter dilemma.

Here’s a simple way to determine how efficient your existing filter is (NOTE: Do this outdoors or with something below the filter so you don’t end up with a mess): Position the filter horizontally, then using common table salt, start pouring 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 really should upgrade your filter to something 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. 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 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 usual MERV ratings and how they connect to efficiencies. This is only a guide, so don’t forget to 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%
Extended pleated

MERV 13-16 >98%
Electronic

Be Careful About High MERV Ratings

While a higher MERV number may offer better filtration efficiency, it is extremely important to understand that too high a MERV filter may also require more to operate your furnace and AC system. The higher the MERV, the less 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 probably be a piece of plywood that prevents ALL contaminants and all the air from entering your Austin home. That's maximum air filtration, but would also be like living in a box.

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 Strand Brothers Service Experts Heating & Air Conditioning representative to verify your system has the capability of moving the proper quantity of air through higher efficiency filters. You probably do not want to sacrifice energy-efficiency for filter efficiency; you want a balance of the two. However, if your family deals with allergies or respiratory problems and the situation necessitates a high MERV rated air filter, consider a whole-home air filtration solution that will achieve 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 protect the comfort equipment itself. The story is different today. Austin area homeowners expect their air filter to save kids from a whole host of harmful pollutants, dust mites, and even prevent the need for dusting. Dare to dream!