AC Not Working?

2. What is the thermostat set on? A/C should be in the "ON" setting and the temperature needs to be set to below room temperature. The fan setting should be set to auto. 

3. Does the thermostat say low battery? If so, replace the battery.  

4. Are the coils (unit) frozen? If so, turn the unit off and turn the fan on and allow it to defrost for a couple of hours. When it has defrosted turn it back on. The most common culprit behind a frozen AC is a dirty/clogged air filter. When your air conditioner doesn't get enough warm air flowing over your evaporator coil, the refrigerant inside gets colder and colder causing it to freeze over.  

5. Check your air filters, a clogged air filter will not allow the unit to run efficiently.  Air filters must be changed every 30 days. 

6. Check your ac vents and ensure that they are open.  

TEMPERATURE DIFFERENCES BETWEEN INSIDE AND OUTSIDE AIR

Generally speaking, an air conditioning system is designed to accommodate up to a 20-degree difference between the outside air and inside air while still keeping around a 55% humidity level which is comfortable.  This means that it is 80 outside your AC can easily reach 70 degrees since that is only a 10-degree temperature difference.  So even if it is 90 degrees out your air conditioner should still easily reach the 70-degree mark.  However, if it is 100 degrees outside, it will be nearly impossible to reach 70 degrees inside without the air conditioner working completely overtime and causing problems such as excess humidity.

If you have your air conditioner set to a temperature that makes that differential more than twenty degrees you will likely run your AC all day long and still not quite reach those desired temperatures.  This becomes a waste of money on your end by overusing a system that was not designed to accommodate what you are trying to do. 

WHAT TEMPERATURE SHOULD YOU SET YOUR THERMOSTAT WHEN IT’S 100 DEGREES?

A good rule of thumb is during the hottest days when the dial reaches 100 degrees it is best to set your AC to somewhere between 75 and 80 degrees.  You can also supplement that slight temperature difference with closed curtains on the sunny side of the building, running ceiling fans, and portable fans in the rooms in which people are present.