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What Happens When You Don’t Change Your Air Filter?


Neglecting to change your air filter has consequences that increase cooling bills, erode air quality and shorten your HVAC system’s life. The filter is your cooling or heating equipment’s first line of defense against airborne particulates. Neglecting to change or clean the filter can result in these specific problems with your system:

  • Slow cooling. A dirty air filter doesn’t let as much air pass through the air handler, resulting in less air blowing through the ductwork. It will take the A/C longer to cool your home and reach the thermostat’s setting, which drives up energy consumption.
  • Poor air quality. Depending on the type of air filter you use, it will trap many of the airborne particulates in your air, including pollen, dust, pet dander and mold spores. As it reaches its saturation point, a clogged filter will start sending those particulates into the air handler, the ductwork and your home’s air. Anyone who has allergies or asthma may experience more symptoms and less comfort, both of which will improve when the air filter is changed. You may also need to have your ductwork professionally cleaned if you run the system routinely with a dirty filter.
  • Frozen evaporator coil. Over time, dust, grime and even mold can collect on the evaporator coil, impeding the heat exchange process. The humidity in the air will have a chance to freeze on the evaporator coil. This slows the cooling process. When the frost melts, it can flood the drain pan, causing water damage to the areas surrounding the air handler.
  • Premature part failure. Dirt and dust on parts can impair their performance. The compressor in the outdoor condenser suffers some of the worst effects of a dirty filter. Should the evaporator coil freeze and the system continue to run, it can irreparably damage the compressor, the system’s most expensive part to replace.

The experts at HVAC & Plumbing Unlimited Heating & Air Conditioning can give you more information about when to change your air filter and the benefits of doing so. We proudly provide HVAC services for homeowners in Northern Virginia.

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