Are You Choosing the Right Air Filter for Your Home?

Published on: January 23, 2015

When you’re at the big-box store, the air filter aisle may not be the most exciting stop. However, choosing the right air filter may save the typical homeowner the headache of an HVAC repair, improve indoor air quality (IAQ) and even save substantial energy dollars. Keep reading through to learn how to choose the right air filter, and why changing it regularly makes good sense.

Choosing the Right Air Filter

Air filters are manufactured in many different types in regards to efficiency, filtering method, materials and life span. There isn’t one universal filter that’s right for every home. The filter that’s right for your needs may be different than the best filter for your neighbor. Decide on what you want from the air filters you choose regarding efficiency rating, IAQ, balancing HVAC efficiency and filter efficiency and the general type of filter, such as mid-efficiency disposable, permanent electrostatic or perhaps a high-efficiency particulate air (HEPA) filter.

Filter Efficiency and IAQ

To choose a filter with the right efficiency for your needs, you must decide what your IAQ needs are. Many people suffer from allergies, asthma and other respiratory ailments. If this is true in your home, you want an air filter that’s suited to capture contaminants that trigger respiratory attacks.

Following are the three categories of airborne contaminants. Most filter packaging lists the most common contaminants, which makes it easier to choose the right one.

  • Particulates consist of airborne substances smaller than 100 microns, such as dust, pollen and pet dander.
  • Micro-organisms are microscopic living organisms, such as mold, fungi, viruses and bacteria, and they typically thrive in the Southeast U.S. region.
  • Odors and chemical vapors are common with cooking, smoking, pets, mold and VOCs, which are volatile organic compounds found in building structure, furnishings, carpets, cleaning supplies and solvents.

The minimum efficiency reporting value (MERV) is a good filter efficiency to guide your decision. Air filter packaging that list MERV numbers, which range from 1 to 20 and reflect low to high efficiency, will typically list the contaminants captured in that filter’s MERV range.

Filter Efficiency vs. HVAC Efficiency

Filters create airflow resistance, which affects HVAC energy consumption. The harder it is for the furnace blower to pull air through the filter, the more electricity it must use. Part of your air filter decision may include a pressure drop rating, which allows you to compare the effect different filters will have on HVAC efficiency. If your concerns lean toward better HVAC efficiency, you could choose a mid-efficiency filter with a MERV rating of 7 or 8. If you would like better indoor air quality, you may select a higher-rated filter (MERV 9-12), or one with a better pressure drop rating.

Generally speaking, you want to avoid low-efficiency filters since they do little for IAQ and allow much more debris through to HVAC components. It won’t take long for debris accumulation to lower HVAC efficiency

Types of Air Filters

The type of filter you choose determines how often it needs to be changed, and the method used to capture contaminants. For example, mid-efficiency pleated disposable air filters generally last up to three months. Permanent electrostatic filters, which are charged to use attraction and impaction to capture contaminants, may last up to eight years. Permanent air filters still need to be washed, which may actually add to the maintenance requirements.

Moreover, it’s possible that if permanent filters aren’t washed thoroughly, mold spores, bacteria and other micro-organisms may survive and can be pulled into the ducts. Read manufacturing packaging carefully to determine maintenance requirements of permanent air filters, and the suggested changing times of disposable types.

Reasons to Change the Air Filter

Now that you’re ready to pick out a filter that serves your needs, remember to change or clean it as suggested by the manufacturer.

  • HVAC malfunction or failure: A clogged air filter causes the blower to work much harder to pull airflow. This could lead to malfunction or failure of the blower and other parts.
  • Energy consumption: The U.S. Department of Energy states that a clogged filter can raise energy consumption by 15 percent. It pays to change the filter as needed.
  • Indoor air quality: If you don’t change the air filter, you lose IAQ points, too.
  • Dirty HVAC components: Debris accumulation on HVAC components decreases heating and cooling efficiency and increases energy bills.

For more expert advice about choosing air filters, please contact us at AirConditioningSouthEast.com for help finding a qualified HVAC technician in your area.