My ac unit is not cooling. It has been running 2 degrees warmer than what I have it set on. I live in Tx and we have been having triple digit temps. For the past two days it has been staying right at what I have it set on. Last night it simply quit cooling. Everything seems to be working. I have noticed a lot of condensation on the copper wire coming from outside unit and is now dry. Could this mean it needs to be charged or something more serious?