Regular maintenance on your air conditioning system is extremely important. Having regular maintenance can help your system to maintain up to 95% of their efficiency, but for every year that your system does not receive maintenance, it can lose 5% efficiency. The evaporator coil and condensing coil are two elements that can have particularly negative effects on your system and your comfort if they become dirty or blocked.

The evaporator coil cools and dehumidifies the air as it flows across it while circulating into your home while the condensing coil cools down hot gas refrigerant, condensing it back into a liquid. These coils are key system components that cool the air in order to keep your air conditioning system running smoothly.

The most common culprit for clogging coils is dust. Your system can naturally become dirty when particles and debris accumulate, especially when sticking to surfaces that are kept damp by condensate. Particles such as soot, pollen and mold can also collect. Installing an air filter helps, but there is no way of preventing the coils from becoming dirty over time. The closely spaced cooling fins also create small spaces where dirt can build up.

Dirty or blocked coils can lead to the following:

  • Decreased performance and lifespan of equipment
  • Increased utility bills
  • Reduced comfort levels inside the home
  • Imbalanced refrigerant levels
  • Blocked airflow through the system

Severely blocked coils can lead to the following:

  • Decreased cooling capacity
  • An overheated compressor which can degrade lubricants and decrease the lifespan of the compressor motor
  • Damaged compressor
  • Ice on the evaporator coil
  • In some cases, a gray layer of dust, dirt or ice can become so think on the AC coils that the airflow through the system is almost entirely blocked

If you have questions or would like to have the coils cleaned on your system, call Ace Hi Plumbing, Heating & Air at 970-667-0300. Cleaning of the evaporator and condensing coils can run anywhere between $300 to $600 depending on the size of your system.



The following signs can indicate a freeze-up or other problems with your air conditioning system:

  • Sudden decrease in performance
  • Reduced airflow from the system’s vents
  • Unusually large amount of condensate drainage
  • Continuously draining system
  • Uncomfortably warm indoor temperature

If you notice any of these problems, we recommend that you turn your AC off immediately and call a professional HVAC company to investigate. Sometimes these symptoms can be subtle, but because the consequences can become severe, it is important to stay alert to the signals your system may be sending. Running a frozen air conditioner without correcting the problem can potentially lead to irreversible damage to the system’s compressor.

Here are some signs that you can check for to help confirm that the indoor evaporator coil is frozen:

  • Ice buildup on the outdoor refrigerant line
  • Ice buildup on the evaporator coil inside the air handler
  • Condensation forming on the surface of the indoor air handler
  • Condensation forming on the surface of the condensate drain
  • Unusually large amount of condensate drainage


Causes of a frozen evaporator coil:

Reduced Air Flow

  • Dirty air filter
  • Return air ducts too small
  • Blocked air ducts
  • Closed or blocked registers
  • Malfunctioning fan

Other Potential Problems

  • Dirty or blocked evaporator coil
  • Blocked drain pipe
  • Refrigerant leak
  • Low outdoor air temperature
  • Too-low nighttime thermostat setting

If you, yourself, have verified that the evaporator coil is frozen, you should leave your air conditioning system off until the coil thaws which generally takes several hours. Without using the air conditioning, turning on the fan can help to speed up the process.

After your system has thawed completely, your wisest move would be to call and HVAC specialist in inspect your system because some causes of a frozen coil can be more serious or technical than others. Also, a refrigerant leak is a serious issue that must be handled by a professional HVAC technician who is certified in the safe handling of AC refrigerant. Ace Hi Plumbing, Heating & Air has NATE-Trained technicians with experience who can diagnose and correct problems your AC system may be having.


ac schematic of system