Do AC Coils Ever Go Bad?


Warm temperatures in Hilton Head, South Carolina can last well into fall. This means a lot of people use their air conditioners for anywhere from six to seven-plus months a year. Extended use of an air conditioner, of course, adds additional wear and tear to it, including its evaporator coils. These AC coils can go bad over time, but proper maintenance can extend their lifespan and optimize cooling efficiency. Although temperatures are cooling, our overview of the importance of maintenance for your heating and cooling system is always relevant.

What Does the AC Coil Do?

Air conditioners produce cooled air much differently than the way a furnace produces warm air. It uses refrigerant to absorb heat from the air and then turns it into the cool air that is distributed throughout the home. As the air conditioner cools the air, any remaining heat is released outside through a vent. The goal of the air conditioner is to remove as much warm air as possible until the thermostat reads your desired temperature. The evaporator coil on the air conditioner is the component that absorbs heat. This is also the component from which the cooled air is released from. It is located close to the air handler, which is usually placed near the blower fan. Made from copper, steel, or aluminum, the evaporator coils consists of tubes that are generally bent into the shape of a U. Evaporator coils are usually placed into panels that are in the shape of an “A.” Lined with thin pieces of metal, the panels allow warm air to pass through very close to the coils, which maximizes the refrigerant’s ability to cool the air. Most people think the refrigerant cools the air, but it actually absorbs heat and as it does, it warms it up and then the warm air evaporates. As water vapor passes by the evaporator coils, it will condense into a liquid, thus being the reason you usually see droplets of water dripping from the air conditioner. This water drips into a condensate pan, which has a drain on it to ensure the water droplets are drained outside of the house.

Evaporator Coils Are Important for Energy Efficiency

The evaporator coil plays a major role in how efficient your air conditioner can cool your home. If you replace the coil with one that isn’t suitable for your HVAC unit, this can lead to inefficient cooling and it puts unnecessary wear and tear on the system. Your unit will have to work harder than it should to keep your home at your desired temperature. Much of the time, if the evaporator coil needs to be replaced, the condenser will as well. A professional HVAC contractor can advise you on the best step to take. The finned area on an evaporator coil performs about 70 percent of the component’s work. The bond area that exists between the fins and its tubing is extremely important as the coil can’t function properly when the bond isn’t made. Over time, though, the bond becomes less efficient because of the expansion and contraction that takes place among the coil. The coil itself is actually constructed not to allow for movement, but the bond between the fins and tubing naturally weakens. Over the course of 20 years, this can lead to a 30 percent reduction in the coil’s efficiency.

Why Do Evaporator Coils Go Bad?

In addition to natural wear and tear, evaporator coils often go bad because of volatile organic compounds (VOCs) that are released into the air from:

  • Building materials
  • Furniture materials
  • Common cleaning solutions

A professional HVAC contractor can inspect your system to see why the coils are going bad.

Knowing How to Keep Evaporator Coils From Going Bad

VOCs not only cause corrosion to evaporator coils, but they can also be harmful to your health. Three simple ways to mitigate this issue is by:

  • Increasing household ventilation
  • Installing a whole-home air purifier
  • Investing in regular HVAC maintenance

Investing in regular HVAC maintenance is the number one way to extend the life of evaporator coils and the entire heating and cooling system. Old Coast Heating & Air Conditioning specializes in a wide variety of HVAC maintenance plans whether it’s for spring or summer air conditioning or fall and winter heating. Contact us today by visiting our website or give us a call at 912-250-5771.