- Poor Airflow
If you have blocked ducts or closed dampers you can cause you’re A/C to not get enough warm air flow (that the a/c pulls out of your house to prevent freezing up) which can cause the condensation on the coil to freeze over. Also if your filters are not clean you can also get poor air flow and cause freezing up
2. Low Refrigerant
Sometimes AC freeze ups can be because of the refrigerant being too low. In a properly running a/c, the refrigerant is passed through the system at a temperature low enough to keep your house cool and form where condensation sometimes outside the lines but not so low that it freezes up.
According to the Joule-Thomson Effect when the air in you’re a/c is not compressed the temperature of the air will decrease as it expands to fill the space. So based on this effect when you have low refrigerant it will expand in your unit and the temperature will drop. Once it drops below freezing point you will start to have frost and ice build up on your lines and evaporator coil.
3. Dirty Coils
The third most common cause of AC freezes is a dirty air conditioner coil.
Evaporator coils not only cool the air inside your home but they also dehumidify your space. They pull water out of the air and this causes condensation that builds up on the coils. Usually your system can handle this no problem however if the drip pan becomes over filled the coil can get waterlogged and freeze up. Dirty coils become an issue because they can get a layer of dirt built up on them which stops the coils from absorbing water fast enough which causes freezing.
4. Damaged Blower Fan
The blower fan gets the systems cold air into the house and the warm out pushed out of the house.
To have you’re A/C run efficiently is to have the correct amount of airflow and air pressure.
If the blower fan breaks or is damaged it changes the amount of air flow in the unit and that results in a build-up of condensation. Too much condensation will result in the coil freezing up because the water cannot drain properly. If you blower is broken it can cause your refrigerant line to freeze up to which could damage your condenser