Will An Undersized AC unit Freeze Up?

Many homeowners wonder how it is possible that even with such scorching heat, how the air conditioner freezes up. There are several reasons behind the freezing of an AC. Your AC relies on a balance of systems working together to remove warm air from your home and bring cold air.
If any systems are not working properly, it will affect the whole system, and you will need an air conditioning repair in Katy.

Why is Your Air Conditioning Unit Frozen?

There are several reasons why your air conditioner freezes up. Read below to know more:

  • Leaking refrigerant: When the level of refrigerant is low in your AC, the evaporator will overreact and might drop below freezing. When the temperature of the evaporator coil drops below freezing, the moisture in the air will turn into ice that builds up on your unit.
    The low refrigerant also indicates a leak somewhere in the unit.

  • Inadequate airflow: Factors responsible for restricted airflow:

    1. Dirty filters
    2. Ductwork filled with dirt and debris
    3. Leaves and debris on the outdoor unit
    4. Closed indoor vents

    When the airflow to the outdoor unit is restricted, warm air will not be able to pass over the evaporator coil. It will hamper the exchange and balancing of warm air from inside with the cooled air from outside. And the evaporator coil will compensate for this by dropping the temperature below freezing.

  • Not properly sized unit: Load calculation is necessary whenever a new AC is purchased for a home. It is the process by which the air conditioners are sized for maximum effectiveness. But if it is performed incorrectly, you might get an AC too small to cover your needs.

    In the case of an undersized unit, the evaporator coil will have to overcompensate by lowering the temperature below freezing for its workload. It will lead to the buildup of ice. And in addition, even after working for hours, your unit will not be able to provide enough cooling to your home.

  • Other reasons: Other mechanical failures might lead your unit to freeze. So if you have any concerns about your air conditioner, call a professional as soon as possible. Sometimes an issue might seem small to you but can lead to costly repairs. 

Steps You can Take to Avoid Freezing of Your Unit

  • Change air filters regularly: It is a very simple task to do for which you don’t need professional help. You should check your filters monthly and make sure to change the dirty filters with a new one.
  • Check for leaking refrigerant: Call a professional immediately if you find signs of leakage in your home.
  • Maintenance plans: You should sign up for maintenance plans. It will ensure that your system is in good shape and working effectively. You can get the maximum of your Air Conditioning Repair Katy, and all the minor issues will be settled before becoming a big problem.
  • Other things
    1. Open the indoor air vents
    2. Maintain and clean your ducts
    3. Remove shrubs and fences that are blocking the airflow
    4. Clean your unit from debris and grass, etc.


If you need any help with your air conditioner or heating system, do not hesitate to call us at Air Mechanic Services. We provide Emergency AC Repair in Katy to solve all your problems, quickly and effectively.