3 HVAC System Issues That Ruin Your Home's Air Quality

You've used your HVAC system for the past several months without any problems. However, you're noticing that your HVAC system is causing you or your family members to have allergies, headaches, or even asthma-like symptoms while active. Instead of continuing to tolerate these problems, determine whether or not these three issues are present in your HVAC system:

Dirty Air Filter

Although your air filter is specifically designed to clean contaminants from the air that flows through your HVAC system, it will have the opposite effect when it's dirty. Your air filter is only capable of trapping a certain amount of dirt, dust, pet fur, and other debris. When enough of this debris collects on your air filter, debris particles will slip through the pores of your filter and contaminate the air that's sent through your furnace or air conditioner.

Luckily, replacing your air filter doesn't require much work. Open the access panel on your HVAC system's blower motor compartment and locate your filter—it will be on the side of your compartment that's connected to your return duct. Pull your filter out of your blower compartment, clean away any remaining debris with a damp rag, and slide in a replacement filter that's compatible with your HVAC system.

Cracked Heat Exchangers

Your gas furnace may have lower operating costs than an electric furnace, but it still has one serious downside: the production of carbon monoxide. Carbon monoxide is a natural by-product of gas combustion. To account for this, your gas furnace ventilates its carbon monoxide production through heat exchangers—long, metal tubes that lead out of your furnace towards a flue or ventilation pipe.

However, heat exchangers can develop cracks when they're used for several years. Due to their metal structure, heat exchangers will expand and contract while hot or cold, respectively. After expanding and contracting thousands of times, your heat exchangers will develop small cracks that will leak carbon monoxide into your home. If you're exposed to even a small volume of carbon monoxide (about 70 parts per million) for a couple hours, you'll experience headaches, fatigue, and even nausea. At higher concentrations, carbon monoxide can cause a loss of consciousness or even death.

Frozen Evaporator Coil

Your air conditioner's evaporator coil is the part that cools the air blowing through your system. While your air conditioner is active, icy cold refrigerant flows through your evaporator coil. When the air flowing through your air ducts passes over your evaporator coil, your coil absorbs the heat from the air and leaves the air cool and slightly humid.

However, if there isn't enough warm air blowing through your evaporator coil, your evaporator coil will freeze—which will cause the metal conduits of your coil to contract and potentially crack. Additionally, the accumulation of frost and ice on your evaporator coil will melt once you deactivate your air conditioner. As your coil freezes and leaks water, your air ducts will become an ideal environment for mildew and mold growth—which will release spores capable of causing respiratory problems for you and your family members.

Your evaporator coil won't freeze simply because the air inside your home isn't warm enough to keep your coil at a reasonable temperature. Instead, your evaporator coil will freeze when there isn't a high volume of air passing through your coil. There are a few issues (including a dirty air filter) that can cause this issue, but the most common issue is a burnt out or malfunctioning blower motor.

If your HVAC system appears to have a clogged air filter, cracked heat exchanger, or mold growth, then contact your local HVAC technician to learn more about getting an inspection and arrange for the necessary repairs. By doing so, you can significantly improve the air quality throughout your home.