The answer to 'AC freezing up' is that a frozen air conditioning unit is a common problem that can be caused by several issues. The most common causes are a dirty air filter, low refrigerant levels, or a problem with the blower fan. Symptoms include reduced airflow, ice buildup on the coils, and the AC unit not cooling properly.
If your AC is freezing up, the first thing to try is replacing the air filter. A dirty filter can restrict airflow and cause the coils to freeze. You can also try increasing the thermostat setting to allow the coils to thaw. If the problem persists, it's best to call a professional HVAC technician to diagnose and repair the issue, as they have the expertise and tools to properly identify and fix the problem.