If your air conditioning is blowing air that’s not especially cool, you are probably low on refrigerant. You most likely have a leak somewhere but it could have been undercharged on the last tune-up.
Adding refrigerant is not a fix, you are going to need to see if there is a leak and if so get it repaired. We recommend calling your local air conditioning experts. This will take a trained expert to repair the leak in the air conditioner, to test the repaired and recharge the system with refrigerant. This is a repair job for an air conditioning technician, air conditioners work best when the amount of refrigerant matches exactly to the manufacturer’s specifications and fixing the leak is not for novices.
If the refrigerant is not properly filled the air conditioner’s performance will be compromised.