• Is your air conditioner freezing up? The idea is of course to keep air cool but if this goes so overboard as to cause the AC unit itself to freeze, then you have a problem. Not only will the system stop cooling due to the ice becoming and air restriction but it can also damage to your HVAC equipment.

    So how do you prevent this happening? And what might be causing it in the first place? Let’s take a look…

    Refrigerant Leak

    Refrigerant (Freon) is a liquid/vapor that is used in heating and air conditioning systems. If you are unlucky enough to have a leak in your system, at a certain pressure we call "the freezing range" the refrigerant is actually too cold and causes the condensation on the indoor evaporator coil to freeze. If left to run long enough like this you literally end up with a iceberg blocking the airflow through the coil. There are 2 options to restore the AC at tbis point:

    • Add either R-22 or R-410A refrigerant to the system depending on the system type.
    • Perform a leak search to find and repair the leak before recharging. This is the most costly option but at the same time will ensure this will not need to be done yearly or more due to an active leak. Each of which will need to be performed by a local HVAC company.

    Insufficient Air Flow

    There are a few things that can cause insufficient air flow including a dirty air filter (this can and will cause a system to freeze), a dirty evaporator coil, a damper that it stuck closed when it should be open and a blower motor not running at it's rated RPM or at all. This does more than just reducing the air pressure. When the air flow across the coil is reduced it causes the coil to become colder than it should be and again will cause the condensation to freeze as it does with a refrigerant leak. The reason AC preventative maintenance is recommended twice yearly is to stop issues like this before they arise. The best thing you can do for your system is changing your filters every 30-45 days and having a maintenance contract to prevent failure and damage to your AC equipment.

    Cold Weather

    It might sound obvious but cold weather can also cause your AC system to freeze up. Most AC units are designed to run at very specific temperatures but if you decide to keep cooling the air even further when it’s already cold, then it’s no surprise this can cause a problem. If the temperature outside is below 62F, then this can cause the pressure inside the system to drop and can lead to potential freezing. The same principal applies if someone was to drop your thermostats to say 50F, first of all it would never come close to reaching that temperature and at the same time the colder the indoor temperature the colder the evaporator coil. Mix that in with a chilly outdoor temperature and ice is on the menu. At Blake & Sons Heating & Air we recommend never setting the thermostat below 68F in air conditioning for these very reasons.