90% of AC problems are caused by a dirty filter. Before calling an HVAC tech, try this:
1. Turn off your AC
2. Find your air filter (usually behind a return vent or in the furnace)
3. If it's gray and dusty, replace it
4. Wait 30 minutes and turn the AC back on
A clean filter can drop your energy bill by 15% and fix most cooling problems. Change it every 3 months!